PALEOGENE LITHOSTRATIGRAPHIC UNITS (BELGIUM)

Pieter LAGA, Stephen LOUWYE & Stéphane GEETS

ABSTRACT

The presented lithostratigraphy of the Paleogene deals only with the formal lithostra-tigraphic units of formation rank or higher (groups). The names of the lower rank units (members and beds) are just mentioned without description or other information. This lithostratigraphy corresponds largely with the legend of the new series of geological maps of Belgium - Flanders Region on scale 1:50.000, edited since 1993.

KEYWORDS: lithostratigraphy, Paleogene, Belgium

1. INTRODUCTION

The Paleogene of Belgium is divided into 23 formations. Eighteen formations are placed into 8 groups: the Chalk Group (Houthem Fm), the Haine Group (Ciply Fm, Mons Fm and Hainin Fm), the Landen Group (Hannut Fm, Tienen Fm), the Ieper Group (Kortrijk Fm, Tielt Fm and Gentbrugge Fm), the Zenne Group (Aalter Fm, Brussel Fm and Lede Fm), the Tongeren Group (Zelzate Fm, Sint-Huibrechts-Hern Fm and Borgloon Fm) and the Rupel Group (Bilzen Fm, Boom Fm and Eigenbilzen Fm). The Opglabbeek Fm, Bertaimont Fm, Heers Fm, Maldegem Fm and Voort Fm are not placed into a group. The occurrences of the paleogene formations are illus-trated in Figs. 1, 2 and 3. A subdivsion of the formations into members or layers is given. However, this subdivision must not be considered as formal since some of the members are still under debate. Stratigraphic units with a rather local significance such as the Hyon Fm and the Onhaye Fm are not yet incorporated in this overview. The latter formation is considered as a tertiary relict found in sinkholes of the Sambre and Meuse region.

2. LITHOSTRATIGRAPHY

2.1. CHALK GROUP

2.1.1. Houthem Formation - Ho

Authors: Romein (1962), Felder (1975), De Geyter & Laga (1988a).

Description: this marine entity consists of soft, pale grey to pale yellow, mostly coarse and porous limestone with firm shell layers and limestone knolls. The basal part looks more greenish and contains glauconite grains. At the contact with the underlying Maastricht Fm, a hard layer with bioturbations ("hardground") is found.

Stratotype: The section between -240 m and -274 m in the borehole Opoeteren (KS 22 or 63E222) can be considered as a hypostratotype. Sheet 26/2 (Opoeteren). Co-ordinates: x = 238.831, y = 191.238, z = +88 m.

Area: the formation is found in the subsoil of Central and North Limburg and in the northern part of the province of Antwerp. It is locally found in outcrops southwest of Maastricht (Vroenhoven).

Members: the formation is subdivided into following members in The Netherlands (Felder, 1975): Geleen Chalk, Bunde Chalk and Geulhem Chalk.

Thickness: probably maximum 63 m (Turnhout).

Age: Early and Middle Danian.

Remarks: the formation is also discussed by Cogels & Van Ertborn (1886), Felder et al. (1985), Gulinck (1961), Hofker (1957), Legrand R. (1968), Marlière (1968), Mei-jer (1965), Moorkens (1972a, 1982), Slimani (1994), Streel et al. (1977) and Vincent (1928).

2.2. HAINE GROUP

2.2.1. Ciply Formation - Ci

Authors: Le Hardy de Beaulieu (1861), Robaszynski (1988a).

Description: the Ciply Fm consists of a white-yellowish, marine calcarenite, with lo-cally different silicification levels. The lime content is very high, attaining sometimes more than 99%. In outcrops the formation starts by a conglomerate, composed of fragments from the underlying Upper Cretaceous sediments: brown pebbles of phos-phatic hardgrounds, more or less rounded, and phosphatised fossil fragments: the "Malogne Conglomerate".

Stratotype: not formally designated. The formation was most completely exposed in the now abandoned and infilled quarry "André" along the road from Mons to Bavay (Ciply). The most closely located outcrop is in the quarry "Vandamme", where at the base of the quarry the "Tuffeau de Ciply" and the "Poudingue de Malogne" outcrop in an approximately 10 m thick section (sheet 45/7-8, Mons - Givry). Coordinates: x = 119.39, y = 122.84, z = +60 m.

Area: the Mons Basin, in outcrops and in boreholes.

Members: the formation is not subdivided into members.

Thickness: some 20 m in the quarries of Ciply and more than 30 m in boreholes.

Age: Middle and Late Danian, based on planctonic Foraminifera.

Remarks: the formation is also discussed by Cornet & Briart (1866), Maréchal (1993), Meijer (1969), Rutot & Van Den Broeck (1886a, 1886b).

2.2.2. Mons Formation - Mo

Authors: Dewalque (1868), Robaszynski (1988b).

Description: the Mons limestone is a pale, marine limestone, friable or sometimes very coherent; it contains a very abundant neritic macrofauna. An erosional surface separates the Mons Fm from the Spiennes Chalk in the borehole of the stratotype. A clear superposition of the Mons limestone on the sediments of the Ciply Fm has never been demonstrated.

Stratotype: "Goffint" pit at Mons (cf. Cornet & Briart, 1865), "Coppée" pit at Mons (cf. Cornet & Briart, 1865; Robaszynski, 1981). Mons borehole (cf. Marlière, 1977). Sheet 45/7-8 (Mons - Givry). Co-ordinates: x = 123.10, y = 128.14, z = +56.8 m.

Area: the central part of the Mons Basin, only in boreholes.

Members: the formation is not subdivided into members.

Thickness: strongly fluctuating, from 15 to nearly 70 m.

Age: Middle and Late Danian.

Remarks: the formation is also discussed by Briart & Cornet (1870-1889), Cornet & Briart (1865), Maréchal (1993), Marlière (1977) and Robaszynski (1979, 1981).

2.2.3. Hainin Formation - Ha

Authors: Le Hardy de Beaulieu (1861), Robaszynski (1988c).

Description: the sediments are from lacustrine - continental origin and consist of lime-stones, grey and white marls, black clays and lignites, and some sands. They rest in the Mons region on the limestones of the Mons Fm.

Stratotype: outcrop along the railroad from Mons to Quiévrain, between Boussu and Thulin. Sheet 45/5-6 (Quiévrain - Saint-Ghislain). The borehole HA1 (1970) near the outcrop penetrated about 30 m of the Hainin Fm. Co-ordinates: x = 107.25, y = 124.89, z = +26 m.

Area: the formation is known in outcrops and boreholes in the region of Hainin and St.-Ghislain (western part of the Mons Basin), and only in boreholes in the region of Mons and Ghlin.

Members: the formation is not subdivided into members.

Thickness: approximately 30 m.

Age: Early Selandian.

Remarks: the formation is also discussed by Godfriaux & Thaler (1972), Godfriaux & Robaszynski (1974), Maréchal (1993), Robaszynski (1978), Rutot (1886) and Steur-baut (1998).

2.3. OPGLABBEEK FORMATION - Op

Authors: De Geyter & Laga (1988b).

Description: a heterogeneous deposit, consisting of dark and reddish clay, small lig-nitic layers, plant remnants, shell-layers and fine sands, locally calcareous. In north-east Limburg a homogeneous sand complex (37 m thick) covers a more clayey entity, whereas in many boreholes only the clayey facies is found.

Stratotype: stratotypes have only been designated for the members.

Area: the northeastern part of Limburg, only in boreholes.

Members: the formation is subdivided into the Opoeteren Mbr and the Eisden Mbr.

Thickness: 25 m in the type area, 60 m in the Molenbeersel well.

Age: Early Selandian.

Remarks: the formation is named after the village of Opglabbeek where the Opoeteren and Eisden members are well represented in borehole 63W215 (KS19). The Maas-mechelen beds are considered a calcareous zone with the sandy Eisden Mbr. The for-mation is also discussed by Felder (1975), Felder et al. (1985), Halet (1932a), Maré-chal (1993), Marlière (1968), Moorkens (1972a, 1972b, 1982), Schmitz & Stainier (1909), Stainier (1931), Steurbaut (1998) and Vincent (1930).

2.4. BERTAIMONT FORMATION - Be

Author: Dupuis (1988).

Description: this marine unit contains, from base to top, three units:

- a grey, sandy, smectite clay, poorly calcareous and glauconiferous, with some peb-bles;

- green, very glauconitic, clayey sands, with some marl layers; disseminated pebbles are present. Polymorphina are frequent, few lamellibranchs and gasteropods occur;

- marls, lithified calcareous marls, grey or yellowish, glauconiferous limestone, with detritic quartz grains and pebbles. Foraminifera, gasteropods and lamellibranchs occur frequently, sometimes abundantly.

Stratotype: for the first time described as the "Heersien" in the "Brasserie Paternostre" borehole at Mons (Delvaux, 1877). Sheet 45/7-8 (Mons - Givry). Co-ordinates: x = 120.32, y = 126.44, z = +31 m. The formation is most complete in borehole no. 7 of the "Charbonnage du Hainaut" (1918) between 65.5 m and 97 m depth (incomplete core recovery) (Saint-Ghislain 138, in Marlière, 1969). Sheet 45/5-6 (Quièvrain - Saint-Ghislain). Co-ordinates: x = 108.90, y = 128.15, z = +24 m.

Area: deepest parts of the Mons Basin, only known from boreholes.

Members: the formation is not subdivided into members.

Thickness: probably not more than 40 m.

Age: Thanetian.

Remarks: the formation is also discussed by De Geyter (1981), Delvaux (1877), Du-puis & Robaszynski (1986), Cornet (1927), Maréchal (1993), Marlière (1969), Moorkens (1982) and Robaszynski (1978).

2.5. HEERS FORMATION - Hs

Authors: Dumont (1849a), Laga & De Geyter (1988).

Description: this marine unit consists mainly of whitish grey, calcareous marl with imprints of leaves, covering green, glauconitic sand.

Stratotype: stratotypes have only been designated for the members.

Area: the eastern part of northern Belgium. Outcrops are locally found in the Hesbaye area, a.o., at Heers and Orp-Jauche.

Thickness: maximum about 60 m in the east. It decreases to the west and to the north.

Members: the formation is subdivided into the Orp Mbr and the Gelinden Mbr.

Age: Middle and Late Selandian.

Remarks: the formation is also discussed by De Geyter (1981), De Saporta & Marion (1873, 1877), Dumont (1851), Gosselet (1874), Gulinck (1965a), Herman (1972), Le-riche (1903), Moorkens (1972b, 1982), Schumacker-Lambry (1978), Steurbaut (1998), Thielens (1871) and Vincent (1873).

2.6. LANDEN GROUP

2.6.1. Hannut Formation - Hn

Author: De Geyter (1988a).

Description: this marine unit consists of clay, sandy clay and silt, siliceous limestone, siltstone and sandstone, mostly covered by glauconitic, fine sand.

Stratotype: stratotypes have only been designated for the members.

Area: the formation extends almost over the whole northern part of Belgium. The out-crops are mainly situated in the Hesbaye area and in Hainaut.

Thickness: the formation thickens to the northeast and reaches more than 100 m in the Campine (Mol borehole). In the Mons Basin the maximum thickness is about 55 m. In East- and West-Flanders the thickness mostly varies between 20 and 40 m, but mark-edly decreases in the north of West-Flanders (Knokke borehole).

Members: the formation is subdivided into the Chercq Mbr (Hainaut), the Lincent Mbr (Hesbaye area), the Halen Mbr and the Waterschei Mbr (northeast Belgium), and the Grandglise Mbr (almost the whole northern part of Belgium).

Age: Early and Middle Thanetian.

Remarks: the formation is also discussed by Baudet (1939), Cornet (1899), De Geyter (1980, 1981), D'Omalius d'Halloy (1939, 1842), Gullentops et al. (1995), Gulinck (1948), Gulinck & Hacquart (1954), Kaaschieter (1961), Lyell (1852a), Macar et al. (1947), Maréchal (1993), Moorkens (1972b, 1982), Nijs & De Geyter (1985), Steur-baut (1998) and Vincent & Rutot (1879).

2.6.2. Tienen Formation - Ti

Author: De Geyter (1988b).

Description: the continental-lagoonal unit mainly consists of lignitic clay and lignite, white sand, pale marl and shell beds. Locally silicified wood fragments, traces of roots and quartzites occur. Important fossil vertebrates have been found at Dormaal and Erquelinnes.

Stratotype: stratotypes have only been designated for the members.

Area: outcrops are known in the Hesbaye area and in Hainaut. The formation occurs in the subsurface in the northern part of West- and East-Flanders and in a part of northeastern Belgium with an extension to the Tienen-Landen area.

Thickness: the maximum thickness is about 35 m.

Members: the formation is subdivided into the Erquelines Mbr (Hainaut area), the Knokke Mbr (northwest Belgium), the Loksbergen Mbr (northeast Belgium) and the Dormaal Mbr (Hesbaye area).

Age: Late Thanetian (- Early Ypresian).

Remarks: the formation is also discussed by Casier (1967), De Coninck et al. (1981), De Geyter (1980, 1981), D'Omalius d'Halloy (1862), Feugueur (1955), Gulinck (1973, 1967), Kaasschieter (1961), Laga & Vandenberghe (1990), Leriche (1899, 1902), Maréchal (1993), Moorkens (1972b), Nijs & De Geyter (1984), Quinet (1966, 1969), Rutot (1881, 1884, 1903), Smith & Smith (1995), Stevens (1913), Steurbaut (1998) and Teilhard de Chardin (1927).

2.7. IEPER GROUP

2.7.1. Kortrijk Formation - Ko

Authors: Geets (1988a), Steurbaut (1998).

Description: the formation is an essentially marine deposit, consisting mainly of clayey sediments.

A standard sequence contains from bottom to top:

- an alternation of horizontally laminated, glauconiferous clayey sands or sandy clay, and compact, silty clay or clayey silt, locally bioturbated. The base consists of oxi-dized and indurated clayey sand, with lenses of pure sand;

- a homogeneous deposit of very fine silty clay, with some thin intercalations of coarse silty clay or clayey, very fine silt;

- a less homogeneous deposit of clayey, coarse or medium silt, with some sand con-taining layers; fossil rich layers occur; the whole deposit becomes more sandy to the east and the south;

- a very fine silty clay.

To the east, in the Brabant and the Campine, and towards the Mons basin, the depos-its become more sandy.

Stratotype: the formation is defined by boundary stratotypes (Steurbaut, 1998). The lower boundary stratotype is placed at 288 m depth in the Knokke borehole at the base of the Het Zoute Mbr. Sheet 5/6 (Westkapelle). Co-ordinates: x = 78.776, y = 226.37, z = +4.91 m. The upper boundary is placed at 71 m depth in the Tielt bore-holes at the top of the Aalbeke Mbr. Sheet 21/6 (Wakken). Co-ordinates: x = 67.425, y = 187.55, z = +48 m.

Area: the formation is found in the western and central part of Belgium. It outcrops in the north of Hainaut, the southern and central part of West-Flanders, the south of East-Flanders Flanders and the southwest of Brabant. Outliers occur in the Mons Ba-sin and south of the river Sambre.

Thickness: 125 m in the northern part of West-Flanders, but the thickness decreases in eastern and southern direction.

Members: the formation is subdivided into the Het Zoute Mbr, Mont Héribu Mbr, Or-chies Mbr, Roubaix Mbr and the Aalbeke Mbr.

Age: Early and Middle Ypresian.

Remarks: the formation is also discussed by Cornet (1874), De Ceukelaire & Jacobs (1998), De Coninck (1973), De Coninck et al. (1983), De Heinzelin & Glibert (1964), De Moor & Geets (1975), Geets (1990), Gosselet (1874), Gulinck (1965a, 1967), Gu-linck & Hacquaert (1954), King (1990), Laga et al. (1980), Lyell (1852b), Maréchal (1993), Ortlieb & Chelloneix (1870), Steurbaut (1988), Steurbaut & Nolf (1986), Vandenberghe et al. (1990) and Wouters & Vandenberghe (1994).

2.7.2. Tielt Formation - Tt

Author: Geets (1988b), Steurbaut (1998).

Description: this marine unit consists in general of a very fine sandy, coarse silt, up-wards there is a transition into very fine sand.

Stratotype: the formation is defined by boundary stratotypes (Steurbaut, 1998). The lower boundary stratotype is placed at 71 m depth in the Tielt borehole at the base of the Kortemark Mbr. Sheet 21/6 (Wakken). Co-ordinates: x = 76.425, y = 187.55, z = +48 m. The upper boundary is placed at the top of the Egem Mbr in the "Ampe" quarry. Sheet 21/1 (Wingene). Co-ordinates: x = 70.15, y = 190.15, z = +44 m.

Area: the western and northern part of Belgium. The formation outcrops in the north of Hainaut, the south and the centre of East- and West-Flanders and the western and southwestern part of Brabant. Outliers occur in the Mons Basin and south of the river Sambre.

Thickness: more than 50 m in the centre of the outcrop area. It decreases to the south and the east, and probably to the north.

Members: the formation is subdivided into the Kortemark Mbr, the Egemkapel Mbr and the Egem Mbr.

Age: Middle to Late Ypresian.

Remarks: the formation is also discussed by De Coninck (1973), De Moor & Geets (1973), Geets (1979), Laga et al. (1980), Maréchal (1993), Steurbaut (1988), Steur-baut & Nolf (1986) and Subgroup Lithostratigraphy and Maps (1980).

2.7.3. Gentbrugge Formation - Ge

Author: new name; see also Geets (1988c) and Steurbaut (1998).

Description: this formation of marine origin consists at the base of a very fine silty clay or clayey, very fine silt. To the south and upwards, it is followed by an alterna-tion of layers glauconiferous, clayey silty, very fine sand and clayey sandy, coarse silt, disturbed by bioturbation. The clayey members are covered by fine sand, clearly horizontally bedded or cross bedded. The sediments contain different layers of sand-stones.

Stratotype: stratotypes have only been designated for the members.

Area: the formation mainly outcrops in the centre of East- and West-Flanders and on the hills in the southern part of East- and West-Flanders. It occurs also in the subsoil of the province of Antwerp and northwest Belgium. Some outliers can be remarked to the south till northern Hainaut and eastwards from the Senne River.

Thickness: maximum 50 m in the north and decreasing to the south and the east.

Members: the formation is subdivided into the Merelbeke Mbr, the Pittem Mbr and the Vlierzele Mbr.

Age: Late Ypresian.

Remarks: the Gentbrugge Fm is still called Gent Fm on the geological maps. The name Gent Fm was changed since it was already in use for Quaternary eolian cover-sand deposits in Flanders (Paepe & Vanhoorne 1976). The formation is also discussed by De Heinzelin & Glibert (1957), De Moor & Geets (1973), De Moor & Germis (1971), Dumont (1851), Fobe (1996), Geets (1979), Gulinck (1967), Gulinck & Hac-quaert (1954), Kaasschieter (1961), Maréchal (1993), Steurbaut & Nolf (1986) and Wouters & Vandenberghe (1994).

2.8. ZENNE GROUP

2.8.1. Aalter Formation - Aa

Authors: Dewalque (1868).

Description: marine unit, consisting of a grey green, glauconiferous, clayey sand with fine sandy clay layers and many thin sandstone layers. It is followed upwards by grey, fine sand, very fossiliferous at the top. The whole is covered by brown green to dark green glauconiferous, very fine, locally silty sand, with many fossil fragments.

Stratotype: a composite stratotype was designated by Steurbaut & Nolf (1989) be-tween Aalter, Molenstraat ("Oude Molen" area), sheet 21/3-4 (Aalter - Nevele), co-ordinates: x = 85.90, y = 197.82, z = +26 m, and Aalter, Weibroekdreef bridge, sheet 21/3-4, co-ordinates: x = 86.15, y = 198.20, z = +19 m. The first mentioned area is considered as a lectostratostype.

Area: the formation occurs in the northeastern part of West-Flanders and the north-western part of East-Flanders Flanders. It outcrops in the region of Aalter, at the base of the hillrow in the northern part of West- and East-Flanders and in a few outliers (Gent, the hills in the south of West-Flanders).

Thickness: 30 m, decreasing to the east.

Members: the formation is subdivided into the Beernem Mbr and the Oedelem Mbr.

Age: Late Ypresian to Early Lutetian.

Remarks: the formation is also discussed by Depret & Willems (1983), Dewalque (1868), Dumont (1839), Geets & Jacobs (1988), Gulinck (1967), Gulinck & Hac-quaert (1954), Hacquaert (1939), Jacobs (1975), Jacobs & Geets (1977), Maréchal (1993), Mourlon (1873), Nolf (1970, 1972) and Steurbaut & Nolf (1989).

2.8.2. Brussel Formation - Br

Authors: Dumont (1839), Houthuys & Fobe (1988).

Description: this rather heterogeneous formation consists of an alternation of strongly and poorly calcareous sets. The non calcareous sands (silica facies) are homogeneous or crossbedded with thin clay layers. They show a lot of silicified borings, spherical or platy concretions. Locally silicified marl layers may occur. The calcareous facies con-sists of finer sands. Subhorizontal laminations are frequently disturbed by bioturbation. Limestone layers occur frequently, together with silicified concretions. The for-mation has been deposited in a marine environment with strong tidal currents. The calcareous sands were deposited in quiet, protected areas.

Stratotype: a lectostratotype is defined in Jodoigne (Zétrud - Lumay area). Sheet 32/7-8 (Meldert - Tienen). Co-ordinates: x = 185.375, y = 161.2, z = +90 m.

Area: Brabant and the north of Hainaut and Namur. The most important outcrops are between the Zenne and the Gete Valleys.

Thickness: 20 to 40 m, exceptionally 70 m.

Members: the formation is subdivided into the Archennes Mbr, the Bois de la Hous-sière Mbr, the Chaumont - Gistoux Mbr, the Diegem Mbr and the Neerijse Mbr.

Age: Early Lutetian.

Remarks: see Lede Fm.

2.8.3. Lede Formation - Ld

Authors: Mourlon (1873), Fobe (1988).

Description: this marine unit consists of calcareous and glauconiferous, fine sand. Some layers of sandy limestone or calcareous sandstone occur (normally three). The base is formed by a pebble layer with reworked elements (fossil fragments and rock fragments) from older deposits. The stone layers are frequently associated with coarse sediment layers (with the coarse base too). Nummulites variolarius is abundantly pre-sent.

Stratotype: Oosterzele - Balegem Quarry. Sheet 22/5-6, (Gavere - Oosterzele). Co-ordinates: x = 110.8, y 179.10, z = +66 m.

Area: the formation occurs in the north of East-Flanders Flanders and Brabant and in a large part of the Antwerp Province. It continually outcrops in the Dender-Zenne re-gion and forms the subsoil of the Flemish Valley in a narrow zone between Zomer-gem and Dendermonde. It occurs in outliers, as the southern hills of West- and East-Flanders and adjacent areas of Hainaut and Brabant.

Members: the formation is not subdivided into members.

Thickness: 10 to 15 m.

Age: Middle Lutetian.

Remarks: the Lede and Brussels formations are also discussed by Dumont (1839, 1851), Fobe (1986, 1988), Fobe & Spiers (1992), Gulinck & Hacquaert (1954), Hout-huys & Gullentops (1985, 1988), Kaasschieter (1961), Leriche (1912), Mignion (1969), Mourlon (1873, 1880, 1887), Rijksgeologische Dienst & Nederlandse Aardo-liemaatschappij (1980), Rutot & Vincent (1879), Subgroup Lithostratigraphy and Maps (1980) and Vincent (1887).

2.9. MALDEGEM FORMATION - Ma

Author: Jacobs (1988).

Description: marine deposit, consisting of a succession of sharp based clays, gradually coarsening upwards into sands. The formation starts with grey, glauconiferous, fine sand, growing more clayey at the top and covered by a strongly glauconiferous clay, with locally coarse glauconitic sand at the base. A homogeneous, less glauconiferous, grey blue, heavy clay is followed by a dark grey, silty fine sand, glauconiferous and micaceous. This sand is covered by a grey blue, heavy clay, which passes into a dark grey, silty fine sand. The formation ends by a grey blue, heavy clay, with perforations at the top, filled by humic, grey, fine sand and a lot of organic material, indicating a soil development or a gap in the sedimentation.

Stratotype: stratotypes have only been designated for the members.

Area: the formation outcrops in a part of the north of West- and East-Flanders and in the region between the Dender and Zenne rivers. It occurs in the subsoil in the whole northern part of West- and East-Flanders and disappears to the east in the Antwerpse Kempen; it forms outliers in the Brabant and South Flanders hillrows.

Thickness: 50 m in the northeast, but only a few meters in the southern outliers.

Members: the formation is subdivided into the Wemmel Mbr, the Asse Mbr, the Ursel Mbr, the Onderdale Mbr, the Zomergem Mbr, the Buisputten Mbr and the Onderdijke Mbr.

Age: Late Lutetian and Bartonian.

Remarks: the formation is also discussed by Jacobs (1975, 1978, 1998), Gulinck (1965b, 1969), Leriche (1921), Rutot (1882), Vincent & Lefevre (1872) and Vincent & Rutot (1878).

2.10. TONGEREN GROEP

2.10.1. Zelzate Formatie - Zz

Authors: Jacobs (1975, 1978), Jacobs & Vandenberghe (1988).

Description: This marine unit starts with a dark grey, moderately fine, silty sand, glauconiferous and micaceous, with intercalations of thick lenses of grey clay; it is covered by dark green, sandy clay. The top is formed by green grey sands, rich in fos-sils, with large sandstone concretions.

Stratotype: stratotypes have only been designated for the members.

Area: northern part of East-Flanders and the Antwerpen Province till the area between the Nete and the Demer rivers.

Members: the formation is subdivided into the Bassevelde Mbr, Watervliet Mbr and the Ruisbroek Mbr.

Thickness: probably 25 to 30 m, decreasing to the east.

Age: Early Priabonian to Early Oligocene.

Remarks: the formation is also discussed by Dumont (1839), Gulinck (1965b, 1969), Halet (1905, 1937), Jacobs & De Coninck (1977), Janssen (1981), Matheussens (1971), Mourlon (1894-1895), Steurbaut (1986, 1992), Vandenberghe (1974) and Van Den Bosch et al. (1975).

2.10.2. Sint-Huibrechts-Hern Formation - Sh

Author: Laga (1988a).

Description: this marine (epicontinental) deposit starts with glauconiferous and mica-ceous, more or less clayey, fine sands, locally very fossiliferous. It is covered by finely laminated glauconiferous sand, passing into white homogeneous sand; at the base occurs a hardened and oxidized shell layer.

Stratotype: stratotypes have only been designated for the members.

Area: the formation is found in the eastern part of Belgium, east of the Dijle Valley and till the north of Limburg, with some outliers between the Zenne and the Dijle Val-leys, especially on the hilltops, southeast and east of Brussels.

Thickness: approximately 25-30 m.

Members: the formation is subdivided into the Grimmertingen Mbr and the Neerrepen Mbr.

Age: Early Oligocene.

Remarks: the formation is also discussed by Buurman & Langenaar (1975), Dumont (1849b), Glibert & De Heinzelin (1954a), Macar & Gulinck (1947), Maréchal (1993), Ortlieb & Dollfuss (1873) and Van Den Broeck (1883a).

2.10.3. Borgloon Formation - Bo

Author: Laga (1988b).

Description: the continental and lagunary deposits start in Brabant by a layer of clay lenses with erosion and emersion characteristics, followed by an alternation of sand and clay layers. It is covered by grey white or brownish, cross bedded sand, locally lignitic. In Limburg the base is formed by a thick layer of grey and green clay, cov-ered by black lignitic clay with horizontal layers of calcareous nodules and gypsum crystals, and an alternation of clayey and sandy layers. The top is formed by white yellowish, medium to coarse sand, with a lot of shells ( fragments) and alternating with 2 to 3 layers of grey white, compact clay with layers of black clay.

Stratotype: stratotypes have only been designated for the members.

Area: southern area of Brabant and Limburg.

Thickness: 20 m in Brabant and 10 m in Limburg.

Members: the formation is subdivided in NE Belgium into the Henis Mbr and the Al-den Biesen Mbr. In the Brabant area, the formation is subdivided into the Heide layer, the Kerkom Mbr, the Boutersem Mbr and the Hoogbutsel layer.

Age: Early Oligocene.

Remarks: the formation is also discussed by Dumont (1849a, 1851), Glibert & De Heinzelin (1952, 1954a, 1954b), Janssen et al. (1976), Macar & Gulinck (1947), Maréchal (1993), Ortlieb & Dollfus (1873), Tavernier & Gulinck (1947) and Van Den Broeck (1881-1882, 1882, 1883b, 1893).

2.11. RUPEL GROUP

Revised: N. Vandenberghe & L. Wouters

Name

The name "Rupélien" was introduced in 1849 by Dumont. The term has been consis-tently used in a chronostratigraphic sense, and nowadays the Rupelian is the interna-tional stage corresponding to the Lower Oligocene (Van Simaeys & Vandenberghe, 2006). The Rupel area is the best suitable area for the lithostratigraphic description of the Rupel Group.

General characteristics

The term Rupel group is designated for the Boom Clay and the sedimentological re-lated fine-grained and clayey deposits. The latter comprise on the one hand the super-jacent Eigenbilzen Sands, a unit much sandier than the Boom Clay, however display-ing in some outcrops the typical rhythmicity of the Boom Clay. The Eigenbilzen Sands are considered as a geometrical and lateral equivalent of the Boom Clay. On the other hand in East-Limburg a sandy unit, the Kerniel Sands splits up the clay unit, the overlying clay designated as Boom Clay and the thinner underlying clay unit as the Kleine-Spouwen Clay (Van Den Broeck, 1883). The Berg Sands, occuring below the Kleine-Spouwen Clay and the Boom Clay, are littoral sands and are considered as a lateral equivalent of a part of the clay.

The age of the Rupel Group is for the larger part Rupelian. The Rupel Group was traditionally considered as Middle-Oligocene in the former threefold division of the Oligocene. In the recent twofold division of the Oligocene, the Rupel Group is equated with the Early Oligocene.

The sand layer, frequently encountered in the subsurface of the Campine area and ly-ing upon the Eigenbilzen Sands, is named the Voort Sands. The age of this sandy unit is Chattian or Late Oligocene. The Voort Sands can be lithologically comparable to the Eigenbilzen Sands.

Type area

Dumont (1849) cited the vicinities of Rupelmonde, Boom and Hasselt as type areas for the clayey upper part of the "Rupélien", while Van Den Broeck (1883) mapped the Berg Sands, the Kleine-Spouwen Clay and the Kerniel Sands in the Bilzen area. It is reasonable to designate both areas as the type area for the Rupelian. The Boom Clay is nowadays excavated in large quarries along the rivers Rupel and Schelde, and in the vicinity of the city of Sint-Niklaas.

Occurrence

The deposits of the Rupel Group occur north of the rivers Durme, Rupel, Dijle, and of the line Leuven - Tongeren. The Rupel Group crops out along the southern rim of this area. The deposits dip to the north and are thus present in the subsurface of the Ant-werp Campine and Limburg Campine areas. The Rupel Group is deeply eroded by the overlying Diest Formation in the Hageland. As a consequence, two outcrop areas can be considered: a western area comprising the Land van Waas, the Rupel area and the Nete-Dijle interfluvium, and an eastern area comprising the Hageland and the Demer area in Limburg.

The Voort Sands do not crop out, and are only present in the north of Limburg. Traces or relicts of this unit have been reported in the area of Hoogstraten-Merksplas, Turn-hout and north of Antwerp.

Subdivision

The Rupel Group is divided into four formations (from young to old):

Voort Formation;

Eigenbilzen Formation;

Boom Formation;

Bilzen Formation.

The Bilzen, Boom and Voort formations are subdivided into members:

Bilzen Formation

Kerniel Member, sand;

Kleine-Spauwen member, clay;

Berg Member, sand.

Boom Formation

Boeretang Member, siltier clay with pronounced layered structure

Putte Member, organic rich, black clays;

Terhagen Member, grey clays;

Belsele-Waas Member, silty clays.

Voort Formation

A clayey part of the Voort Formation in the northeastern part of the country was de-scribed as the Veldhoven Clay, following a subdivision used in The Netherlands. However, the significance of the terms Voort and Veldhoven, as defined in the strati-graphic nomenclature of The Netherlands (Van Adrichem Boogaert & Kouwye, 1993), differs from this simple scheme. It is proposed to use the name Voort Forma-tion for this unit above the Eigenbilzen Sand.as in Belgium the unit is dominated by sands; in case a thick.clay layer is observed in the unit, the clay can be designated as the Veldhoven Member. It is furthermore unclear whether two types of clay are pre-sent in this unit: marine clays deposited in the deeper parts of the basin (following the scheme by Mulder et al., 2003), and continentally influenced clays with lignites (Hager et al., 1998)

2.11.1. Bilzen Formation - Bi

Name

The name was for the first time used in a publication by Marechal (1993). Bilzen is a village in South East Limburg. It is also the name of the geological map made by Van Den Broeck (1883) and Van Den Broeck & Rutot (1883).

General characteristics

The Bilzen Formation is only encountered in the Hageland and Limburg. The forma-tion consists essentially of sandy sediments (the Kerniel Member and the Berg Mem-ber) with a clayey intercalation (the Kleine-Spouwen Member). The formation rests on the underlying Tongeren Group. The upper boundary is with the superjacent Boom Formation.

Occurrence

The formation crops out in the south of the Hageland and Limburg. Further north, the formation occurs in the deeper parts of the subsurface of the eastern Campine.

Subdivision

Kerniel Member, sand;

Kleine-Spuwen Member, clay and marl;

Berg Member, sand.

Former designations

Geological map 1/40.000: R1 + R2a + R2b

Stratigraphical register (1929, 1932): R1 + R2 p.p.

New geological map 1/50.000: Bi

2.11.1.1. Berg Member

Name

The name was introduced by Van Den Broeck (1883) in an explanatory note of the geological map Bilzen (scale 1/20.000). Berg is a hamlet northeast of Tongeren, and is a dependent municipality of the city of Tongeren (Limburg province).

General characteristics

Dark and flattened flint nodules are present in the base of the Berg Sands. The sands consist in the area Leuven-Tienen-Tongeren area of yellowish to white, slightly glauconitic, medium-grained quartz sands (modal value of grain size 100-175 µm). The littoral sands are homogenous to - especially in the lower part of the member - hori-zontally layered. Molluscs are occasionally present (a.o. Astarte, Glycymeris and Cy-prina) (Glibert & de Heinzelin, 1954; Glibert, 1955 & 1957).

Occurrence

The Berg Member occurs in the Leuven-Tienen-Tongeren area, and slightly north of this area. The upper boundary of the member is with the superjacent Boom Formation or the Kleine-Spouwen Member, while the lower boundary is with the underlying Tongeren Group. The thickness of the Berg Member is maximum 5 m.

Stratotype

Van Den Broeck refers to the "gîte classique de Berg", an outcrop along a southward oriented road on the southern slope of the small hill on which the hamlet Berg is located.

For references concerning this site: Glibert & de Heinzelin, 1954 (p. 301, point 200); archives Belgian Geological Survey: nr. 93W-243; map 34/1-2 (Bilzen-Veldwezelt).

Co-ordinates: X = 233.040; Y = 171.340; Z = + 105 m.

Former designations

Geological map 1/40.000: R1b (+ R1a basal gravel)

Stratigraphical register (1929, 1932): R1

New geological map 1/50.000: BiBe.

2.11.1.2. Kleine-Spouwen Member

Name

The name was introduced by Van Den Broeck (1883) in an explanatory note of the geological map Bilzen (scale 1/20.000). The name is here used in the sense defined by Van Den Broeck (1883). Formerly, the term was used for a unit comprising the Berg Sands and, as well, the late Tongrian Oude-Biezen Sands (Vieux-Joncs) (de Heinzelin & Glibert, 1956, p. 96). Kleine-Spouwen is a village in South East Limburg, and is now a dependent municipality of Bilzen.

The spelling Kleine-Spauwen or Klein-Spauwen was often used in the French literature.

General characteristics

The member consists of greenish to yellowish grey clay, sometimes brownish at the top because of the oxidation. The member is frequently calcareous with numerous Nucula compta. The occurrence of calcareous concretions has been described. The fossils indicate a fully marine depositional environment.

Occurrence

The clay occurs in South Limburg (Sint-Truiden-Tongeren as far as Genk, Water-schei, Winterslag) and East Limburg (Maasmechtelen-Eisden).

The lower boundary of the member is with the Berg Member and the upper boundary is with the Kerniel Member or the Boom Clay in the Genk, Waterschei and Winter-slag area (Gulinck, 1975, Belgian Geological Survey document MG/75/338). The member is also present - although reduced in thickness - in the Roelants Quarry in Lubbeek-Pellenberg (between Leuven and Tienen), where it is barely distinguishable from the overlying Terhagen Member (Boom Formation). The member has a maxi-mum thickness of 5 m.

Stratotype

Van Den Broeck (1883) refers to the top of the hill of Kleine-Spouwen. This site was already described by Ortlieb & Dolfuss (1873) and by Rutot (1873). A lithological profile of the site was given by Glibert & de Heinzelin (1954, fig. 12, p. 306) and by Van Den Broeck (1883, p. 44, fig. 4).

Profile of the outcrop at Kleine-Spouwen between points A and B: sheet 34/1-2 (Bil-zen-Veldwezelt).

Co-ordinates point A: X = 233.18, Y = 170.42, Z = + 117 m.

Co-ordinates point B: X = 232.860, Y = 170.250, Z = + 122 m.

Former designations

Bosquet (1851): Clay with Nucula compta (or comta)

Geological map 1/40.000: R1c

Stratigraphical register (1929, 1932): R2a

New geological map 1/50.000: BiKs.

2.11.1.3. Kerniel Member

Name

The term Sands and Gravel of Kerniel are introduced by Van Den Broeck (1883) in an explanatory note of the geological map Bilzen 1/20.000. The village of Kerniel lies north of Borgloon and is now a dependant municipality of Borgloon (Limburg prov-ince).

General characteristics

The member consists of medium-grained, rather fine-grained, white to yellowish, brownish quartzitic sand. Mica and glauconite are rare (Batjes, 1958). According to Kruissink et al. (1978), the base of the member is often clayey, and the transition with the underlying Kleine-Spouwen Member is gradual. The Kerniel Sands can consist of an alternation of more or less clayey layers.

The Kerniel gravel - which occurs in the middle of the sandy deposit - consists of rounded quartz pebbles, milky-quartz pebbles and flint pebbles. This horizon is some-times indurated and can contain intercalations of plastic clay.

Occurrence

The Kerniel Member occurs in South Limburg (Sint-Truiden, Tongeren unto Genk) and East Limburg (Maasmechelen, Eisden). The lower boundary is with the Kleine-Spouwen Member and the upper boundary is with the Boom Formation. The thick-ness of the member is approximately 7 m.

Stratotype

Outcrop along the railroad Looz-Kerniel, at Kerniel (Van Den Broeck, 1883).

This coutcrop is not accessible anymore. Furthermore, it has been argued whether the once observed sands already belonged to the Miocene (Gullentops, personal observa-tion).

Former designations

Geological map 1/40.000:

R1d: sands below gravel

R2a: gravel

R2b: sands above gravel

Stratigraphical register (1929, 1932): no record

New geological map 1/50.000: BiKe

2.11.2. Boom Formation - Bm

Name

The name Boom Clay has been cited for the first time by De Koninck (1837). Boom is a town along the river Rupel (Antwerp province).

General characteristics

The Boom Clay is a grey silty clay or clayey silt with fairly constant chemical and mineralogical properties. This clay is rich in pyrite and contains glauconite in the most silty horizons. The clay is typically banded with layers of about 20 to 50 cm thickness, expressed by rhythmic variations in silt content, land-derived organic mate-rial and carbonates. Typically septaria have developed in the calcareous horizons. All these thin layers occur in a well-defined vertical succession, remaining constant in the outcrop area. In the subsurface the upper part of the clay becomes more sandy east of Mol but in the lower part of the clay the layer succession known from the outcrop area can be identified. Therefore the rhythms can be used as a microstratigraphic instru-ment (Vandenberghe, 1978; Vandenberghe et al., 2001).

Mollusc content is limited in numbers but several species have been described, domi-nated by a.o. Leda deshayesiana (Vincent, 1889; Glibert, 1957). The ecological an-alysis of the fauna and flora in the clay, leaves no doubt about the marine character of the deposit. The Boom Clay has been deposited in an open shelf sea under warm cli-matic conditions, as an aerobic mud at an approximate depth of about 50m or even a few tens of meter deeper.

Type area

The area in which the clay traditionally is exploited for a.o.brick making along the Rupel between Rumst and Boom and along the Scheldt between Temse and Antwerp is designated as the type area of the Boom Clay.

Occurrence

The Boom Clay Formation outcrops in the Waasland and north of the Rupel and Nete rivers. North of this outcrop area the clay occurs in the subsurface.

The Boom Clay Formation is underlain by the Bilzen Formation (Berg Member, Kleine-Spouwen Member, Kerniel Member) in Limburg and Flemish-Brabant and by the Zelzate Formation (Ruisbroek Member) in the provinces of East-Flanders and Antwerp. The Boom Clay Formation is overlain by Pliocene deposits (Waasland area), Miocene deposits (Antwerp and Brabant provinces), the Eigenbilzen Formation (east of the Antwerp province and Limburg), locally by the Voort Sand (north of Antwerp and in the north of the Antwerp province) or by Quaternary deposits in the outcrop area.

The thickness of the Boom Clay varies between a few meter in the southern part of the Waasland, 40 m in Rupel area, 80 m in the Antwerp area and till 150m in North Belgium; to the east its thickness diminishes.

Subdivision

In the outcrop area of the Waasland and the Rupel area, the Boom Clay Formation can be lithologically split up in three members:

Belsele-Waas Member;

Terhagen Member;

Putte Member;

In addition, a fourth member has been identified in the Campine subsurface, namely the Boeretang Member.

In all these members lithologically distinct layers systematically occur.

As these layers have a microstratigraphic significance some of the prominent layers can be considered as key horizons for correlation and therefore formally designated with a stratigraphic 'bed' status.

All layers in the outcrop area have been numbered by Vandenberghe (1978, p.39). Based on a detailed analysis of cores and geophysical borehole logs, related to the NIRAS/ONDRAF SCK/CEN research project for the deep storage of nuclear waste, a more complete and logically constructed numbering scheme has been developed (Mertens & Wouters, 2003) represented in figure 4 together with the litholog. This new numbering system keeps identical numbers as in the outcrop area for the layers 10 to 59. In his study of the Weelde borehole Van Simaeys (2004, fig. C2, p175) has numbered all the resistivity wiggles conformably the numbering in the outcrop area above the layer 10 and the additional younger section conformably the numbering system as elaborated by Mertens & Wouters (2003). In their study of the borehole ON-Dessel 1 Abels et al. (2007) have introduced another numbering system; their study of the periodicities in the resistivity signal needed to characterise all details in the signal.

A remarkable example is the layer 39 sensu Abels et al. (2007), easily recognisable on resistivity logs but less well outspoken in field logging (see fig. 139 in Vandenberghe, 1980) and therefore not individually numbered; nevertheless the original grain size data (Vandenberghe 1978) already suggested the presence of an additional silt hori-zon, later confirmed by detailed analyses (Van Boven, 1998).

Especially in the lower thick silt layers a consistent numbering between areas will be difficult as the thickness of this basal part of the clay increases to the northeast (com-pare e.g. the boreholes Reet and ON-Dessel-1 on fig.7 in Vandenberghe et al. (2001), with a numbering only appliquable to this specific figure). Abels et al. (2007) have numbered all the details of these basal silty layers and continued the numbering from this lower part upwards. This difficulty is also the reason that the numbering of Van-denberghe (1978) and Van Simaeys (2004) below layer 10 differs from the numbering in Mertens & Wouters (2003). The difference in numbering of the layers 60 to 68 in Vandenberghe (1978) and Mertens & Wouters (2003) can be explained by the prac-tice in Vandenberghe (1978) to additionally number septaria layers occurring in the middle of a silt- and clay layer (see e.g. layer 9=S10 in Vandenberghe, 1978). The different numbering systems and their correspondence is shown in figure 4; for details of the numbering of the basal silty layers, the original references have to be consulted. Regarding the Boeretang Member in the Boom Clay Formation, the numbering of the silty resistivity layers is also indicated.

It is proposed to give a formal 'bed' status to (numbers between brackets refer to Vandenberghe, 1978):

- pink horizon R (nr 21)

- boundary surface between grey and black clay (between layers nr 31 and 32), also very well expressed in the natural gamma ray logs.

- the very silty to fine sandy double layer (layers nr 39-41)

- the septaria layer S20 characterised by large and numerous septaria (nr 14)

- the septaria layer S50 characterised by platy septaria containing multicoloured pyrite crystals in the septae (nr 49)

- the septaria layer S60, conatining siderite, rusty coloured, with visible bioturbation tracks (nr 56).

These layers are figured in Vandenberghe (1978, photographs 3, 4,5,6).

Previous designations

In the description of the area around Bilzen, Van Den Broeck (1883) uses the term "glaise schistoïde du Limbourg".

Geological Map 1/40.000: R2c

Stratigraphical Register (1929,1932): R2b

New Geological Map 1/50.00: Bm.

2.11.2.1. Belsele-Waas Member

Name

The name refers to the S.V.K. clay pit in which the member is exposed and which is situated in Belsele -Waas, a part of the town of Sint-Niklaas (East- Flanders prov-ince).

General characteristics

The Belsele-Waas Member represents the lowermost, more silty part of the Boom Formation; it is characterised by the absence of black organic rich horizons and in particular by the occurrence of two unusual thick layers at its base basis (Vanden-berghe, 1978, photo 8, p. 37). Based on the grain-size properties and evolution (see e.g. Vandenberghe et al., 2001, Fig. 2) this Member has been formally defined as the unit between the base of the Boom Clay and the base of septaria- or calcareous bed S10. However on geophysical resistivity logs, in particular the two thick silt layers at the base delineate an easily recognisable unit very usefull for corelation purposes in the subsurface. As such use of geophysical borehole logs is a common practice it is proposed to make the top of the Belsele-Waas Member coincide with the top of the thick silty layers ( many examples can be found in the figures in Vandenberghe et al.,2001).

Occurrence

The Belsele-Waas Member can be mapped in the Waasland. It is always present at the base of the Boom Clay except in the most southernly outcrop area (Leuven area) where it has been laterally replaced by a more sandy facies, the Berg Sands (see fig. 4 in Vandenberghe et al.,2001).

The Member is limited at its base by the Ruisbroek Member of the Zelzate Formation and at its top by the Terhagen Member of the Boom Clay Formation. The thickness of the Member is usually slightly less than 10 m. A detailed comparison between the Member in the boreholes Reet and Dessel-1 is given in fig.7 in Vandenberghe et al. (2001).

Stratotype

The clay exploitation pit of the company Scheerders Van Kerkhove (S.V.K.) at Sint-Niklaas, Belsele-Waas; topographic map sheet 15/5-6 (Sint-Niklaas-Temse).

Coordinates: X = 132.500; Y = 205.000; Z = + 17 m.

As the clay pit is still in exploitation the coordinates may slightly change with time.

Subdivisions

The basis is formed by a gravelly layer of mainly phosphatised internal shell moulds and worm tracks. The phosphatised sediment is the fine glauconite bearing sand of the underlying Ruisbroek Sand. In Belgium, this basal layer is only found in the Sint-Niklaas area (Vandenberghe, 1978; Janssen, 1981). This phosphorite horizon can be given a formal bed status. A detailed description of this bed and its stratigraphic sig-nificance can be found in Vandenberghe et al. (2002).

Former designations

Geological map 1/40.000: R2c p.p.

Stratigraphical Register (1929, 1932): R2b p.p.

New Geological Map 1/50.000: BmBw.

Although no formal name was given to this Member, the silty base of the Boom Clay in the type area was long recognised and indicated by the special symbol 'R2b' by Halet (1936) and Gulinck (1965) (see discussion in Vandenberghe, 1974, p. 186).

The Belsele-Waas Member was originally incorporated in the Waasland Clay (see 2.11.2.2. Terhagen Member: Former designations).

2.11.2.2. Terhagen Member

Name

The name refers to the municipality of Terhagen (at present part of the municipality of Rumst; Antwerp province) in the Rupel area.

General characteristics

The Terhagen Member is the middle part of the Boom Clay in the outcrop area. The base of clay layer 5 (sensu Vandenberghe, 1978) forms the basis of the Terhagen Member. The Member consists of pale grey clay, it is the least silty part of the Boom Clay Formation and it only contains two outspoken black organic rich layers. In its lower part it is calcareous but its upper part, starting with the R-bed is free of carbon-ates and it displays a pink to brownish hue.The boundary with the overlying Putte Member is situated between the layers 31 and 32 (sensu Vandenberghe, 1978). Its thickness in the outcrop area is about 20 m.

Occurrence

The Terhagen Member occurs everywhere in the outcrop area above the Belsele-Waas Member. In the Leuven area, where the latter Members is absent the Terhagen Mem-ber overlies the Berg Sand. The Terhagen Member is overlain by the Putte Member.

In East-Limburg the lower part of the Boom Clay overlying the Kerniel Sand (Van-denberghe et al., 2001) ( Fig. 1).

Stratotype

The lower part of the active clay exploitation front along the cuesta between Rumst and Boom (VANDENBERGHE, 1978, photo 2, p. 25) ; map sheet 23/3-4 (Boom-Mechelen).

Coordinates: X = 154.000; Y = 197.500; Z = + 30 m.

Previous designations

Geological map 1/40.000: R2c p.p.

Stratigraphical Register (1929, 1932): R2b p.p.

New Geological Map 1/50.000: BmTe

A twofold subdivision of the Boom Clay in a lower grey clay and an upper black clay, respectively named Waasland Clay and Putte Clay, was proposed earlier by VAN-DENBERGHE (1974, fig. 8.1. and p. 186; 1978). The present name of Terhagen Member replaces the Waasland clay in which originally also the Belsele-Waas Mem-ber was included.

2.11.2.3. Putte Member

Name

The term has been introduced by Vandenberghe (1974, fig. 8.1., p. 16). Putte is a municipality in the south of the Antwerp province.

General characteristics

The Putte Member overlies the Terhagen Member and can be easily distinguished by the systematic occurrence of black organic rich layers and the occurrence of relatively thin very silty layers.Therefore the clay is darker than the Terhagen Member (see Vandenberghe, 1978, photo 6, p. 33). The contact between both Members is always easily observed in outcrops as well as on natural gamma ray borehole logs. Towards its top the Putte Member clearly becomes more siltier. The boundary with the overly-ing Boeretang Member (Fig.1) is defined at the level where a clear shift occurs to even more silty layers, in particular well visible on geophysical resistivity logs, at silt-layer 0 (rsee figs 1,3).

Occurrence

The Putte Member occurs everywhere the Terhagen Member occurs. It is limited be-low by the Terhagen Member and above by, subsequently from west to east, Pliocene, Miocene, Oligocene (Boeretang Member, Eigenbilzen Formation and locally the Voort Formation) and again Miocene deposits. The thickness can be over 50 m but it can be significantly reduced by erosion. In the outcrop area is can also be directly overlain by Quaternary deposits.

Stratotype

The upper part of the active clay exploitation front along the cuesta between Rumst and Boom; map sheet 23/3-4 (Boom-Mechelen).

Coordinates: X =154.000; Y = 197.500; Z = + 30 m.

Previous designations

Geological Map 1/40.000: R2c p.p.

Stratigraphical Register (1929, 1932): R2b p.p.

New Geological Map 1/50.000: BmPu

2.11.2.4. Boeretang Member

Name

The introduction of the term Boeretang Member is the outcome of the extensive bore-hole investigations related to the subsurface nuclear waste disposal research project at Mol-Dessel and in the whole Campine area by NIRAS-ONDRAF. Boeretang is small locality and it has given its name to an upper interval in the Boom Clay with outspo-ken silt layering, particularly well expressed in geophysical resistivity logs (Mertens & Wouters, 2003).

General characteristics

The resistivity and also the gamma ray logs show a clear and gradual increase in silt content compared to the underlying Putte Clay Member.The outspoken very silty lay-ers can be correlated layer by layer and numbered 0 to 9 (see a.o. Vandenberghe et al. 2001 and fig.1).In between the silty layers occur normal clay layers.

Conform the NIRAS-ONDRAF practice in the Mol-Dessel area,it is proposed to de-fine the Boeretang Member between the lowest and the uppermost of these silt layers, respectively numbered 0 on the logs (layer 99 on fig.4) and 9 on the logs. The sedi-mentology and the physical properties of the Boeretang Member are closely related to the underlying Boom clay. Above the Boeretang Member, lithology and log signature change to a clear sandy facies that will be designated as the Eigenbilzen Formation.

Occurrence

The Boeretang Member is typically present in the subsurface of the northern Antwerp Campine area.The Member is already partly present in the boreholes of Zoersel and Herentals but it is just missing in borehole Doel 2b (see figures in Vandenberghe et al., 2001).

Stratotype

It is proposed to use the cores from the well Weelde (SCK-NIRAS) as reference. Borehole measurements and micropaleontological data of this well can be found in the studies by De Man (2006) and Van Simaeys (2004).

Other designations

Neerdael et al. (1981) have been the first to draw the attention to this particular silty sediment package in the wells at Mol, Balen and Retie and these authors have desig-nated this interval as the 'transition layers' Because of the correlatable resistivity wig-gles in that interval, the interval has also been designated as 10-Wig package. Based on the subdivisions that could be made on the geophysical well logs in all silty and sandy sediments in the top of the 'Boom clay' an informal system W0, W1, W2, W3 was applied in Vandenberghe et al., (2001) (see also figs. 1,3). The Boertang Member corresponds in this scheme to the top W0, W1 and the basis W2 (see fig.3).

2.11.3. Eigenbilzen Formation - Eg

Name

The sandy unit lying above the Boom Clay was already recognised in Limburg by Van Den Broeck (1884, 1893), and denominated by the symbol R2d. Gulinck (see for instance BGD-document MG/75/338) introduced the term Eigenbilzen Sands while describing wells. Eigenbilzen is a dependant municipality of Bilzen (Limburg provin-ce).

General characteristics

The Eigenbilzen Formation consists of dark green, glauconite rich, clayey, fine-grained to medium-grained sands, with bioturbations. As in the Boom Formation, a banded structure caused by grain size variations is observed in the outcrops along the Albert Canal. The thickness of the clayey sands can in the subsurface amounts up to more than 50 m.

Occurrence

The formation crops out along the Albert Canal east of Hasselt. Well log analysis in the Antwerp and Limburg provinces indicates the systematic presence of these sandy deposits east of the Mol-Rauw fault and its southern extensions. Furthermore the unit can be divided into informal subunits characterised by an upward increase in grain size (see fig. 1). Matthijs (1999) defined and subdivided in an analogue way the Ei-genbilzen Sands while drawing the geological map Hasselt (1/50.000, explanations, fig. 10).

Sandy and silty deposits are present above the Boom Clay west of the Mol-Rauw fault (Mol area and north more to the north). These deposits can also be divided in several subunits. The formal lithostratigraphic scheme distinguishes a lower Boeretang Mem-ber (belonging to the Boom Formation) and above even more siltier and sandier de-posits, attributed to the Eigenbilzen Formation. More subunits can be recognised within the unit based on geophysical well logs (fig. 3). In the Antwerp Campine area, the uppermost clay layers disappear in the Eigenbilzen Formation (see fig. 3).

These silty to sandy layers west of the fault have most probably no direct genetical or sedimentological relation with the Eigenbilzen Formation east of the fault. However, for practical reasons, it is advisable to incorporate all silty and fine-grained layers, between the underlying Boom Caly and the superjacent Voort or Berchem formations, into the Eigenbilzen Formation. This is analogous and conform with the practice of including - more to the east - the sandy facies between the Boom Clay and the Voort Formation in the Eigenbilzen Formation (see Matthijs, 1999; see also well logs in Vandenberghe et al., 2001).

A detailed sedimentological analysis of the Eigenbilzen Formation is still lacking. It is however to be expected that the well log subdivisions from the east (see a.o. Vanden-berghe et al., 2001, fig. 15), and the deposits west of the Mol-rauw fault, will be ele-vated to the status of member. This can be anticipated since the Eigenbilzen Forma-tion in the Mol area (above the Boertang Member) displays a noteable lower sand fraction than at the Albert canal sluices near Diepenbeek and Hasselt.

Stratotype

No permanent outcrops exist. The sands have been studied in the temporary outcrop when sluices were installed on the Albert Canal near Diepenbeek and Hasselt (Van-denberghe, 1974), and during the enlargement of the latter canal near Gellik (Steur-baut et al., 1999). The latter outcrop allowed a calibration of the boundary between the Boom Clay and the Eigenbilzen Sands near the place of the original definition, i.e. Eigenbilzen (see Halet, 1932; Vandenberghe et al., 2001). The lower part of the Ei-genbilzen Formation appears to become more sandy towards the north (see also Mat-thijs, 1999, fig. 11).

Reference sections with geophysical well logs and analysed core samples are ap-praently non-existent.

Former designations

Geological map 1/40.000: R2d

Stratigraphical register (1929, 1932): no entry

Halet, 1932: R2d

New geological map: Eg.

2.11.4. Voort Formation

Vandenberghe, 2000.

Name

The term was introduced by Van Straelen (1923) while the describing coal wells in Limburg. Voort is a hamlet of the municipality Zolder is the Limburg province.

General characteristics

The Voort Formation consists of fine-grained and clayey, dark green glauconitic sands, rich in fossils. Gulinck (1954) remarked that the lower part of the Voort Sands passes gradually into the underlying Eigenbilzen Sands without noticeable boundary.

Occurrence

The formation is principally known from the subsurface of North and East Limburg. The upper boundary of the formation is with the Miocene Houthalen Sands, and to the west with the Miocene Berchem Formation. The lower boundary is with the Eigenbil-zen Formation. The thickness of the Formation in Belgium is maximum 75 m.

During the recent geological mapping, the formation was also recorded in the north of the Antwerp province. Also along the river Scheldt - north of the city of Antwerp - relicts of the Voort Sands have been observed based on the presence of the fo-raminifer Nonion roemeri (Vandenberghe & Laga, 1986).

Stratotype

Coal mine shaft at Voort-Zolder (archives Belgian Geological Survey 62W-226); ref-erence section from -21 m to -45 m (de Heinzelin & Glibert, 1956, p. 202); geological map 25/3-4 (Beringen-Houthalen).

Co-ordinates: X = 217.330, Y = 192.725, Z = + 48,5 m.

Subdivision

The intercalation of silty clay in the Voort Sands is described as the Veldhoven Clay. This clay layer is recorded north of the Grote Brogel fault in the Roer Valley Graben.

It is common practice in The Netherlands to use the term Veldhoven Formation, sub-divided into the Voort Sands Member and the Veldhoven Clay Member (NAM and RGD Nomenclator, 1980). In the revision of the Dutch stratigraphic nomenclature by Van Adrichem Boogaert & Kouwe (1993) three depositional cycles are distinguished within the Voort Sands Member, each consisting of a clayey horizon in a dominantly sandy unit. Above the Voort Sands Member lies the Veldhoven Clay Member, essen-tially consisting of clay and already partly with an Aquitanian age. The Someren Sands Member is the uppermost unit.

The scheme by De Mulders et al (2003, Fig. 172) indeed shows this succession but the entire formation is called Veldhoven Formation, with the Voort and Someren units located in the upper part, and the deeper water deposits of the Veldhoven Clay in be-tween.

It is proposed to use in Belgium the denomination Voort Formation for all deposits above the Eigenbilzen Sands, since sandy sediments (i.e. the Voort Sands) dominate in the unit. When clayey intercalations are recorded, these can then be referred to as belonging to the Veldhoven Member.

It is furthermore unclear whether two types of clay are present in this unit: marine clays deposited in the deeper parts of the basin (following the scheme by Mulder et al., 2003), and continentally influenced clays with lignites (Hager et al., 1998)

Van Simaeys (2004) divided the Chattian deposits into three sequences based on bio-stratigraphical arguments. The latter author also described two gravel layers, respec-tively at the base of the middle and upper sequence. Vandenberghe et al. (2004) corre-lated these sequences with units proposed by Hager et al. (1998).

Former designations

Geological map 1/40.000: no reference

Stratigraphical register (1929, 1932): Voort Sands: Chattian (Ch) p.p.

New Geological map 1/50.000: Vo.

2.11.4.1. Veldhoven Member

Name

The name was mentioned for the first time in Van Staalduinen et al. (1979, p. 25, 29) and is described in the NAM-RGD Nomenclator (1980, p. 51-52). Veldhoven is a municipality south of Eindhoven in The Netherlands.

General characteristics

The Veldhoven Member consists of grey-green clay. A study of the Chattian deposits in the euregion The Netherlands - Belgium - Germany by Hager et al (1998) shows that clayey deposits occur in the graben and thus north of the Grote Brogel fault. The clays are interpreted as deltaic deposits, while the glauconitic sands have a marine origin. The interpretation of the Asten-2 well in the latter study, compared with an interpretation of the same well by Van Adrichem Boogaert & Kouwe (1993), indi-cates that the clay unit 1 in Molenbeersel (see fig. 4 in Hager et al., 1998) can be re-garded as the Veldhoven Member sensu Van Adrichem Boogaert & Kouwe (1993).

Occurrence

The Veldhoven Member does not crop out, and is only recorded in the subsurface north of the Grote-Brogel - Heerleheide faults.

Stratotype

The Veldhoven Member is in Belgium rather silty and the unit was until now only encountered in wells in North East Limburg. The reference section in the Dutch well Veldhoven-1 (NAM-RGD, 1980, p. 51, encl. 32) can be used as a stratotype.

Former designations

None in Belgium

 

3. OVERVIEW AND SYMBOLS OF THE PALEOGENE LITHOSTRATIGRAPHIC UNITS

Chalk Group

Houthem Formation

Ho

Haine Group

Ciply Formation

Ci

Mons Formation

Mo

Hainin Formation

Ha

Opglabbeek Formation

Op

Bertaimont Formation

Be

Heers Formation

Hs

Landen Group

Hannut Formation

Hn

Tienen Formation

Ti

Ieper Group

Kortrijk Formation

Ko

Tielt Formation

Tt

Gentbrugge Formation

Ge

Zenne Group

Aalter Formation

Aa

Brussel Formation

Br

Lede Formation

Ld

Maldegem Formation

Ma

Tongeren Group

Zelzate Formation

Zz

Sint Huibrechts Hern Formation

Sh

Borgloon Formation

Bo

Rupel Group

Bilzen Formation

Bi

Boom Formation

Bm

Eigenbilzen Formation

Eg

Voort Formation

Vo

4. ACKNOWLEDGEMENTS

The former chairman R. Maréchal and the members of the Subcommission of Ter-tiairy Stratigraphy are thanked for their constructive remarks and their efforts to make this synthesis possible.

5. REFERENCES

ABELS, H.A., VAN SIMAEYS, S.,HILGEN, F.J.,DE MAN, E., VANDEnBERGHE, N. , 2007. Obliquity-dominated glacio-eustatic sea-level change in the early Oli-gocene: evidence from the shallow marine siliciclastic Rupelian stratotype (Boom Formation, Belgium). Terra Nova, 19, 65-73

Anoniem 1892 - Légende de la Carte Géologique de la Belgique (40.000ième). Bull. Soc. belge Géol., 6, 217-219.

Anoniem 1896 - Légende de la Carte Géologique de la Belgique (40.000ième). Bull. Soc. belge Géol., 10, 37-59.

Anoniem 1900 - Légende de la Carte Géologique de la Belgique (40.000ième). Bull. Soc. belge Géol., 14, 19-42.

Anoniem 1909 - Légende de la Carte Géologique de la Belgique, à l'échelle du 40.000e. Ministère de l'Industrie et du Travail, Dir. Gén. des Mines, Commission Géologique de Belgique, Bruxelles, t. XIV, 16-35.

Anoniem 1929 - Légende générale de la carte géologique détaillée de la Belgique. Ann. Mines Belg., t. XXX, 1ière liv.

Anoniem 1932 - Algemeen stratigrafisch register van de uitvoerige aardkundige kaart van België. Met bijlage: De nuttige stoffen van den Belgischen bodem. Ministerie van Nijverheid, Arbeid en Maatschappelijke Voorzorg. Algemene Directie van het Mijnwezen, Aardkundige Raad.

BATJES, D.A.J., 1958. Foraminifera of the Oligocene of Belgium. Verhandelingen Koninklijk Belgisch Instituut voor Natuurwetenschappen, 143.

BAUDET, J., 1939. Quelques observations sur les morts-terrains du Tournaisis. Bul-letin de la Société belge de Géologie, 49: 289-299.

BRIART, A., CORNET, F.L., 1870-1889. Description des fossiles du Calcaire gros-sier de Mons. Mémoire Couronnée de l'Académie royale des Sciences, Lettres, Beaux-Arts de Belgique, 1(1870), t. 5: 1-76; 2(1873), t. 37: 1-94; 3(1880), t. 43: 4(1889), t. 47: 1-128.

BUURMAN, P. & LANGENAAR, W.D., 1975. Depositional Features in Oligocene Tidal sediments of Valkenburg, Province of Limburg, The Netherlands, with the de-scription of a new lithostratigraphical Unit: Valkenburg Deposit. Mededelingen van de Werkgroep Tertiaire en Kwartaire Geologie, 12(2): 57-72.

CASIER, E., 1967. Le Landénien de Dormaal (Brabant) et sa faune ichthyologique. Verhandelingen Koninklijk Belgisch Instituut voor Natuurwetenschappen, 156: 1-66 (profielbeschrijving p. 7-9).

COGELS, P. & VAN ERTBORN, O., 1886. De l'infraheersien et du niveau occupé par le Crétacé sur le territoire de la feuille de Bilsen. Annales de la Société royale de Malacologie de Belgique, 21: 57-62.

CORNET, J., 1874. Compte-rendu de l'excursion du 31 août aux environs de Ciply. Bulletin de la Société Géologique de France, 2(3): 567-577.

CORNET, J., 1899. C.R. Exc. du 3 avril 1899 à Stambruges, Grandglise, Hautrages, Sirault et Villerot. Bulletin de la Société belge de Géologie, 13: PV 126-129.

CORNET, J., 1927. Leçons de Géologie. Maurice Lamertin, Editeur, Bruxelles.

CORNET, F.L. & BRIART, A., 1865. Note sur la découverte dans le Hainaut en-dessous de sables rapportés par DUMONT au système landénien, d'un calcaire gross-ier avec faune tertiaire. Bulletin de l'Académie royale de Belgique, 2(20): 757-776.

CORNET, F.L. & BRIART, A., 1866. Description minéralogique, paléontologique et géologique du terrain crétacé de la province de Hainaut. Mémoire Couronnée de la Société des Sciences, Lettres, Beaux-Arts de Belgique. Hainaut, Dequesne - Mas-quelier, Mons, p. 1-199.

DE CEUKELAIRE, M. & JACOBS, P., 1998. Indeling van de Formatie van Kortrijk op basis van kwalitatieve interpretatie van resistiviteitsmetingen. Natuurwetenschap-pelijk Tijdschrift, 78: 27-51.

DE CONINCK, J., 1973. Application stratigraphique des microfossiles organiques dans l'Yprésien du Bassin belge. Bulletin de la Société belge de Géologie, 81(1-2): 1-11.

DE CONINCK, J., DE DECKER, M., DE HEINZELIN, J. & WILLEMS, W., 1981. L'âge des faunes d'Erquelinnes. Bulletin van de Belgische Vereniging voor Geologie, 90: 121-154.

DE CONINCK, J., GEETS, S. & WILLEMS, W., 1983. The Mont-Héribu Member: Base of the Ieper Formation in the Belgian Basin. Tertiary Research, 5(2): 83-104.

DE GEYTER, G., 1980. Bijdrage tot de kennis van de lithostratigrafie en de sedi-mentpetrologie van de Formatie van Landen in België. Doctoraal proefschrift, Uni-versiteit Gent, p. 1-230.

DE GEYTER, G., 1981. Contribution to the lithostratigraphy and the sedimentary pe-trology of the Landen Formation in Belgium. Mededelingen van de Koninklijke Aca-demie voor Wetenschappen, Letteren en Schone Kunsten van België, Klasse der Wetenschappen, 43: 111-153.

DE GEYTER, G., 1988a. Formatie van Hannut. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brus-sel, p. 60-71.

DE GEYTER, G., 1988b. Formatie van Tienen. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brus-sel, p. 72-80.

DE GEYTER, G. & LAGA, P., 1988a. Formatie van Houthem. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geolo-gische Dienst, Brussel, p. 34-38.

DE GEYTER, G. & LAGA, P., 1988b. Formatie van Opglabbeek. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geolo-gische Dienst, Brussel, p. 39-47.

DE HEINZELIN, J. & GLIBERT, M., 1956. Rupélien, Voort, Boncelles, Berg. In Lexique Stratigraphique International, vol. I: Europe, Fasc. 4a, VII.

DE HEINZELIN, J. & GLIBERT, M., 1957. France, Belgique, Pays-Bas, Luxem-bourg. Tertiaire. In: Lexique Stratigraphique, Vol. I, Fasc. 4a, VII.

DE HEINZELIN, J. & GLIBERT, M., 1957. Lexique Stratigraphique International. Vol. I. Europe, Fasc. 4a: France, Belgique, Pays-Bas, Luxembourg. Fasc. 4a VII: Ter-tiaire. 217 p., 15 maps. Congrès Géologique International - Commission de Strati-graphie, Mexico, 1956. Centre National de la Recherche Scientifique, Paris, VIIe, 1957.

DE KONINCK, L.G., 1837. Description des coquilles fossiles de l'argile de Basele, Boom, Schelle, etc. Mémoires de l'Académie royale de la Belgique, 11: 37.

DE MAN, E., 2006. Benthic Foraminifera biofacies analysis and stable isotopes of the middle Eocene to Oligocene successions of the southern North Sea Basin : tools for stratigraphy and for reconstruction of extreme climate changes. Doctoral Thesis Ge-ology, K.U. Leuven , Belgium , 375p.

DELVAUX, E., 1877. Note sur un forage exécuté à Mons en septembre 1876. An-nales de la Société Géologique de Belgique, IV: 51-65.

DE MOOR, G. & GEETS, S., 1973. Sedimentologie en lithostratigrafie van de eocene afzettingen in het zuidoostelijk gedeelte van de Gentse agglomeratie. Natuurweten-schappelijk Tijdschrift, 55: 129-192.

DE MOOR, G. & GEETS, S., 1975. Applications de quelques méthodes sédimen-tologiques à l'étude des dépôts éocènes du bassin Flamand. Ixe Congrès Internation-ale de Sédimentologie, Thème 5, Synthèse sédimentologique des bassins sédimen-taires, 2: 305-312.

DE MOOR, G. & GERMIS, A., 1971. Hydromorphologie du Bassin de la Molenbeek (Melle). Bulletin de la Société belge, Etude Géographique, 40: 29-68.

DE MULDER, E.J., GELUK, M.C., RITSEMA, I.L., WESTERHOF, W.E., WONG, T.E. (eds) , 2003. De ondergrond van Nederland. 379p Wolters Noordhoff Gronin-gen /Houten.

DEPRET, M. & WILLEMS, W., 1983. A record in situ of Nummulites laevigatus (Brugière 1892) in sediments of Lutetian age in the area around Zeebrugge (NW-Belgium) and its stratigraphical consequences. Tertiary Research, 5(1): 25-37.

DE SAPORTA, G. & MARION, A.F., 1873. Essai sur l'état de la végétation à l'é-poque des marnes heersiennes de Gelinden. Mémoire Couronnée et des Saventes étrangers de l'Académie royale de Belgique, 37: 1-94.

DE SAPORTA, G. & MARION, A.F., 1877. Révision de la flore heersienne de Ge-linden d'après une collection appartenant au Comte G. DE LOOZ. Mémoire Couron-née et des Saventes étrangers de l'Académie royale de Belgique, 41: 1-112.

DEWALQUE, G., 1868. Prodrome d'une description géologique de la Belgique. De Decq, Bruxelles - Liège, p. 1-442.

D'OMALIUS D'HALLOY, J., 1839. Eléments de géologie, 3e édition. Paris, p. 285-286.

D'OMALIUS D'HALLOY, J., 1842. Coup d'oeil sur la géologie de la Belgique. Hayez, Bruxelles, p. 78-79.

D'OMALIUS D'HALLOY, J., 1862. Abrégé de Géologie. A. Schnée, Bruxelles, Leipzig & Leiber, Paris, p. 535.

DUMONT, A., 1839. Rapport sur les travaux de la carte géologique pendant l'année 1839. Bulletin de l'Académie Royale des Sciences, Lettres et Beaux-Arts de Belgique, 6: 464-485.

DUMONT, A., 1850a. Rapport sur la carte géologique du Royaume. Bulletin de l'A-cadémie royale de Belgique, (1), 16(2) (année 1849): 351-373.

DUMONT, A., 1850b. Rapport sur les travaux de la carte géologique en 1839, avec une carte géologique des environs de Bruxelles. Bulletin de l'Académie royale de Belgique, 16 (2): 464-485.

DUMONT, A., 1851. Note sur la position géologique de l'argile rupelienne et sur le synchronisme des formations tertiaires de la Belgique, de l'Angleterre et du Nord de la France. Bulletin de l'Académie royale de Belgique, 18 (2): 179-195.

DUPUIS, Ch., 1988. Formation de Bertaimont. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brus-sel, p. 48-51.

DUPUIS, Ch. & ROBASZYNSKI, F., 1986. Tertiary and Quaternary deposits in and around the Mons Basin. Documents for a field trip. Mededelingen van de Werkgroep Tertiaire en Kwartaire Geologie, 23: 3-19.

FELDER, W.M., 1975. Lithostratigrafie van het Boven-Krijt en het Dano-Montien in Zuid-Limburg en het aangrenzende gebied. In Zagwijn, W.H. & Van Staalduinen, C.J., eds., Toelichting bij de geologische overzichtskaarten van Nederland. Rijksgeologische Dienst Haarlem, p. 63-65.

FELDER, P.J., BLESS, M.J.M., DEMYTTENAERE, R., DUSAR, M., MEESSEN, J.P.M.T. & ROBASZYNSKI, F., 1985. Upper Cretaceous to Early Tertiary deposits (Santonian - Paleocene) in north-eastern Belgium and South Limburg (the Nether-lands) with reference to the Campanian and Maastrichtian. Professional Papers of the Belgian Geological Survey, 1985/1(214): 1-151.

FEUGUEUR, L., 1955. Essai de synchronisation entre les assises saumâtres du Tha-nétien-Landénien (Gand-Ostende) et du Sparnacien (Ile de France). Bulletin de la So-ciété belge de Géologie, 64: 67-92.

FOBE, B., 1986. Petrografisch onderzoek van de coherente gesteenten van het Eoceen in Laag- en Midden-België. Doctoraatsthesis, Rijksuniversiteit Gent, Gent.

FOBE, B., 1988. Formatie van Lede. In Maréchal, R. & Laga, P., Voorstel lithostrati-graphische indeling van het Paleogeen. Belgische Geologische Dienst, Brussel, p. 136-140.

FOBE, B., 1996. Lithostratigraphy of the Vlierzele Formation (Ypresian, NW Bel-gium). Bulletin van de Belgische Vereniging voor Geologie, 104(1-2): 133-149.

FOBE, B. & SPIERS, V., 1992. Sedimentology and facies distribution of the Lede Formation (Eocene) in Belgium and Northern France. Contributions to Tertiary and Quaternary Geology, 29(1-2): 9-20.

GEETS, S., 1979. De overgang Ieperiaan-Paniseliaan in de streek van Roeselare en Tielt. Natuurwetenschappelijk Tijdschrift, 60: 41-69.

GEETS, S., 1988a. Formatie van Kortrijk. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brus-sel, p. 81-96.

GEETS, S., 1988b. Formatie van Tielt. In Maréchal, R. & Laga, P., Voorstel lithostra-tigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brussel, p. 97-104.

GEETS, S., 1988c. Formatie van Gent. In Maréchal, R. & Laga, P., Voorstel lithostra-tigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brussel, p. 105-115.

GEETS, S., 1990. The evolution of the grain size distribution of the sediments of the Ieper Formation in Belgium. Bulletin van de Belgische Vereniging voor Geologie, 97(3-4): 451-456.

GEETS, S. & JACOBS, P., 1988. Formatie van Knesselare. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brussel, p. 118-126.

GLIBERT, M., 1955. Quelques espèces nouvelles ou mal connu de l'Oligocène mo-yen et supérieur de la Belgique. Bulletin de l'Institut Royal des Sciences Naturelles de Belgiques, 31, nr. 86.

GLIBERT, M., 1957. Pélécypodes et gastropodes du Rupélien supérieur et du Chat-tien de la Belgique. Mémoir de l'Institut Royal des Sciences Naturelles de Belgiques, nr. 137.

GLIBERT, M. & DE HEINZELIN, J., 1952. Le gîte des vertébrés tongriens de Hoog-butsel. Bulletin de l' Institut Royal des Sciences Naturelles de Belgique, 28 (52).

GLIBERT, M. & DE HEINZELIN, J., 1954a. L'Oligocène Inférieur Belge. In Vo-lume jubilaire Victor Van Straelen 1925-1954. Institut Royal des Sciences Naturelles de Belgique, 1: 281-438.

GLIBERT, M. & DE HEINZELIN, J., 1954b. Le gîte des vertébrés tongriens de Hoogbutsel. Bulletin de l'Institut Royal des Sciences Naturelles de Belgiques, 30 (1).

GODFRIAUX, I., & THALER, L., 1972. Note sur la découverte de dents de mammi-fères dans le Montien continental du Hainaut (Belgique). Bulletin de l'Académie royale de Belgique, Classe des Sciences, p. 536-541.

GODFRIAUX, I. & ROBASZYNSKI, F., 1974. Le Montien continental et le Dano-Montien marin des sondages de Hainin (Hainaut, Belgique). Annales de la Société Géologique de Belgique, 97: 185-200.

GOSSELET, J., 1874. L'étage Eocène inférieur dans le Nord de la France et en Bel-gique. Bulletin de la Société Géologique de France, 2: 598-617. / Annales de la Socié-té Géologique du Nord, 1: 64-66.

GULINCK, M., 1948. Oude natuurlijke bouwmaterialen in Laag- en Midden-België. Technisch Wetenschappelijk Tijdschrift (Antwerpen), 18 (2): 25-32.

GULINCK, M., 1954. L'Oligocène de la Basse et de la Moyenne Belgique. In: CA-LEMBERT ET GULINCK: L'Oligocène (Chapitre 15). In: Prodrome d'une descrip-tion géologique de Belgique. Liège,p. 494-532.

GULINCK, M., 1961. Aperçu général des formations postpaléozoiques de la Belgi-que. Septième Colloque européen de micropaléontologie (Pay-Bas et Belgique) 23-30 septembre 1961. Guide d'excursion.

GULINCK, M., 1965a. Aperçu général sur les dépôts Eocènes de la Belgique. Bulle-tin de la Société Géologique de France, 7ème série, 7: 222-227.

GULINCK, M., 1965b. Le passage du Bartonien au Rupélien dans la région Boom-Malines. Bulletin de la Société belge de Géologie, 74: 115-119.

GULINCK, M., 1967. Profils de l'Yprésien dans quelques sondages profonds de la Belgique. Bulletin de la Société belge de Géologie, 76: 108-113.

GULINCK, M., 1969. Le sondage de Kallo (au nord-ouest d'Anvers). I. Coupe résu-mée des terrains traversés au sondage de Kallo et profil géologique NS passant par Woensdrecht-Kallo-Halle. Mémoires pour servir à l'Explication des Cartes Géologi-ques et Minières de la Belgique, 11: 3-7.

GULINCK, M., 1973. Note sur l'extension des faciës fluvio-lagunaires du Landénien de la Belgique. Toelichtende Verhandelingen voor de Geologische en Mijnkaarten van België, 13: 3-12.

GULINCK, M., 1975. Belgische Geologische Dienst, Document MG/75/338.

GULINCK, M. & HACQUAERT, A., 1954. L'Eocène inférieur. In: Prodrome d'une description géologique de la Belgique. H. Vaillant-Carmanne, Liège, p. 451-493.

GULLENTOPS, F., CLAES, S. & VANDENBERGHE, N., 1995. De geologische kaart van België, Vlaams Gewest, kaartblad (32) Leuven. Brussel, Belgische Geolo-gische Dienst en ANRE.

HACQUAERT, A., 1939. De overgang van Ieperiaan tot Lutetiaan te Aalter (Kanaal). Natuurwetenschappelijk Tijdschrift, 21(7): 323-325.

HAGER, H., VANDENBERGHE, N., VAN DEN BOSCH, M., ABRAHAM, M., VON DER HOCHT, F., RESCHER, K., LAGA, P., NICKEL, E., STRAELEN, A., LEROI, S. & VAN LEEUWEN, R.J.W., 1998. The geometry of the Rupelian and Chattian depositional bodies in the Lower Rhine district and its border area: implica-tions for Oligocene lithostratigraphy. Bulletin of the Geological Society of Denmark, 45: 53-62.

HALET, F., 1905. Coupe du puits artésien de la caserne d'artillerie à Malines. Bulletin de la Société belge de Géologie, 20: 61-69.

HALET, F., 1932a. Les formations infraheersiennes du Limbourg belge. Bulletin de la Société belge de Géologie, de Paléontologie et d'Hydrologie, 42: 23-34.

HALET, F., 1932b. La géologie du flanc occidental de la vallée de la Meuse à l'ouest de l'enclave de Maestricht d'après les sondages d'etude du Canal Albert. Bulletin de la Société belge de Géologie, 42: 195-225.

HALET, F., 1936. La géologie de la vallée du Rupel entre Willebroeck et Boom. Le Néogène et l'Oligocène entre Hasselt et Genck. Bulletin de la Société belge de Géologie, 46: 190-199.

HALET, F., 1937. La Géologie de la Vallée de l'Escaut, à Tamise. Bulletin de la So-ciété belge de Géologie, 47: 356-362.

HERMAN, J., 1972. Les Vertébrés du Landénien inférieur (L1a ou Heersien) de Ma-ret (Hameau d'Orp-le-Grand). Bulletin de la Société belge de Géologie, 81: 191-207.

HOFKER, J., 1957. Een nieuwe laag in het Bovenste Krijt van Zuid-Limburg. Natu-urhistorisch Maandblad, 46: 121-123.

HOUTHUYS, R. & FOBE B., 1988. Formatie van Brussel. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brussel, p. 127-135.

HOUTHUYS, R. & GULLENTOPS, F., 1985. Brusseliaan faciëssen en hun invloed op het reliëf ten zuiden van Brussel. Bulletin Belgische Vereniging voor Geologie, 94: 11-18.

HOUTHUYS, R. & GULLENTOPS, F., 1988. Tidal transverse bars building up a longitudinal sand body (Middle Eocene, Belgium). In: De Boer, P., Van Gelder, A. en Nio, S.: Tide influenced sedimentary environments, 153-166.

JACOBS, P., 1975. Bijdrage tot de lithostratigrafie van het Boven-Eoceen en het On-der-Oligoceen in noordwest België. Doctoraal proefschrift, Rijksuniversiteit Gent, 182 p. en bijlagen.

JACOBS, P., 1978. Litostratigrafie van het Boven-Eoceen en het Onder-Oligoceen in Noordwest België. Professional Papers Belgische Geologische Dienst, 151: 1-92.

JACOBS, P., 1988. Formatie van Maldegem. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brus-sel, p. 141-160.

JACOBS, P., 1998. Monografie van de lithostratigrafie van het Midden- en Boven-Eoceen in het westelijk Belgisch Bekken. Natuurwetenschappelijk Tijdschrift, 78: 160-183.

JACOBS, P. & DE CONINCK, J., 1977. Sedimentologische en micropaleontolo-gische kenmerken van het Eo-Oligoceen te Waasmunster. Natuurwetenschappelijk Tijdschrift, 59: 157-183.

JACOBS, P. & GEETS, S., 1977. Nieuwe ontwikkelingen in de kennis van het Bo-ven-Paniseliaan. Natuurwetenschappelijk Tijdschrift, 59: 57-93.

JACOBS, P. & VANDENBERGHE, N., 1988. Formatie van Zelzate. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brussel, p. 181-189.

JANSSEN, A.W., 1981. Molluskenfauna's en stratigrafie van oligocene afzettingen in een tweetal kleigroeven te Sint-Niklaas, provincie Oost-Vlaanderen, België. Annalen van de Koninklijke Oudheidkundige Kring van het Land van Waas, 84(2): 9-39.

JANSSEN, A.W., VAN HINSBERGH, V. & CADEE, M.C., 1976. Oligocene depos-its in the region North of Tongeren (Belgium), with the description of a new lithostra-tigraphical unit: The Atuatuca Formation. Mededelingen van de Werkgroep Tertiaire en Kwartaire Geologie, 13(3): 75-115.

KAASSCHIETER, J., 1961. Foraminifera of the Eocene of Belgium. Verhandelingen van het Koninklijk Belgisch Instituut voor Natuurwetenschappen, 147: 1-271.

KING, C., 1990. Eocene stratigraphy of the Knokke borehole. In Laga, P. & Vanden-berghe, N., eds, The Knokke well (11E/138) with a description of the Den Haan (22W/276) and Oostduinkerke (35E/142) wells. Toelichtende Verhandelingen voor de Geologische en Mijnkaarten van België, 29: 67-102.

KRUISSINK, E.C., VAN HINSBERGH, V.W.M. & JANSSEN, A.W., 1978. Een oost-west profiel door Oligocene afzettingen in de gemeente Borgloon (België, pro-vincie Limburg). Mededelingen van de Werkgroep Tertiaire en Kwartaire Geologie, 15(1): 3-18.

LAGA, P., 1988a. Formatie van Sint-Huibrechts-Hern. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Di-enst, Brussel, p. 164-169.

LAGA, P., 1988b. Formatie van Borgloon. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brus-sel, p. 169-180.

LAGA, P. & DE GEYTER, G., 1988. Formatie van Heers. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brussel, p. 52-58.

LAGA, P., GEETS, S., MOORKENS, T. & NOLF, D., 1980. A lithostratigraphic scheme for the NW-European Tertiary Basin. In Kockel (comp.), Subgroup Lithostra-tigraphy and Maps (IGCP 124). Newsletter Stratigraphy, 8(3): 236-237.

LAGA, P. & VANDENBERGHE, N., 1990. The Knokke well (11E/138) with a de-scription of the Den Haan (22W/276) and Oostduinkerke (35E/142) wells. To-elichtende Verhandelingen voor de Geologische en Mijnkaarten van België, 29: 1-117.

LEGRAND, R., 1968. Le Massif de Brabant. Toelichtende Verhandelingen voor de Geologische en Mijnkaarten van België, 9: 1-148.

LE HARDY DE BEAULIEU, Ch., 1861. Guide Minéralogique et Paléontologique dans le Hainaut et l'Entre-Sambre-et-Meuse. Mémoire Couronnée de la Société des Sciences, Lettres, Beaux-Arts de Belgique. Hainaut, Renard éd., Liège, p. 1-120.

LERICHE, M., 1899. Notice sur les fossiles sparnaciens de la Belgique et en particu-lier sur ceux rencontrés dans un récent forage à Ostende. Annales de la Société Géo-logique du Nord, 28: 280-283.

LERICHE, M., 1902. Les poissons paléocènes de la Belgique. Mémoires Musée Roy-ale d'Histoire Naturelle de Belgique, 2(5): 1-48.

LERICHE, M., 1903. Sur les horizons paléontologiques du Landénien marin du Nord de la France. Annales de la Société Géologique du Nord, 32: 231-252.

LERICHE, M., 1912. L'Eocène des bassins parisien et belge. (livret-guide de la ré-union extra-ordinaire de la Soc. Géol. de France). Bulletin de la Société Géologique de France, série 4, 12: 692-807.

LERICHE, M., 1921. Monographie géologique des collines de la Flandre française et de la province belge de la Flandre occidentale (Collines de Cassel et des environs de Bailleul). Mémoires pour servir à l'Explication de la Carte Géologique détaillée de la France. Imprimerie Nationale, Paris, p. 1-112.

LYELL, C., 1852a. On the Tertiary strata of Belgium and French Flanders. Part II. The Lower Tertiairies of Belgium. Quaterly Journal of the Geological Society of London, 8: 361-362.

LYELL, C., 1852b. The Tertiary strata of Belgium and French Flanders. Quaterly Journal of the Geological Society of London, 8: 276-370.

MACAR, P. & GULINCK, M., 1947. "Les Roches Siliceuses et Conglomératiques exploitées en Belgique ". Association des Ingénieurs de Liège - Centenaire Congrès 1947 - Section Géologie. Liège, p. 130-140.

MACAR, P., TAVERNIER, R. & GULINCK, M., 1947. Le tuffeau de Lincent. In Centenaire de l' association des ingénieurs de Liège, Congrès 1947 - Section Géolo-gie, Liège, 1947, p. 326-328.

MARECHAL, R., 1993. A new lithostratigraphic scale for the Palaeogene of Bel-gium. Bulletin Belgische Vereniging voor Geologie, 102(1-2): 215-229.

MARLIERE, R., 1968. Projet de légende stratigraphique du Crétacé supérieur. Pro-fessional Papers Belgische Geologische Dienst, 14: 1-4.

MARLIERE, R., 1969. Les faciès et l'extension du Heersien dans le Bassin de Mons. Annales de la Société Géologique de Belgique, 92: 51-77.

MARLIERE, R., 1977. Sur le stratotype du Montien à Mons. Avant-propos; histori-que; le sondage de Mons, vers une délimitation du stratotype. Mémoires pour servir à l'Explication des Cartes Géologiques et Minières de la Belgique, 17: 3-25.

MATHEUSSENS, M., 1971. Geologisch onderzoek op het kaartblad Heist-op-den-Berg. Niet-gepubliceerde licentiaatsscriptie, Rijksuniversiteit Gent, Gent, p. 1-91.

MATTHIJS, J., 1999. Toelichtingen bij de Geologische kaart van België, Vlaams Gewest, Kaartblad 25, Hasselt 1:50.000. Ministerie van de Vlaamse Gemeenschap, Afdeling Natuurlijke Rijkdommen en Energie, Brussel, 104 p.

MEIJER, M., 1965. The stratigraphical distribution of Echinoids in the Chalk and Tuffaceous Chalk in the neighbourhood of Maastricht (Netherlands). Mededelingen Geologische Stichting, nieuwe ser., 17: 21-25.

MEIJER, M., 1969. Les foraminifères planctiques du Tuffeau de Ciply (stratotype); leur signification bio- et chronostratigraphique. In: Proceedings of the 1st International Conference Plankt. Microfossils, Geneva. E.J. Brill, Leiden, p. 414-419.

MERTENS, J. & WOUTERS, L., 2003. 3D Model of the Boom Clay around the HADES-URF. Report NIROND 2003-02 .

MIGNION, G., 1969. Les sablières de la province du Hainaut et la partie wallonne de la province de Brabant. Annales des Mines, p. 951-981.

MOORKENS, Th., 1972a. Foraminifera of the Montian stratotype and of subjacent strata in the Obourg well, with a review of Belgian Paleocene Stratigraphy. Doctoraal Proefschrift, Universiteit Utrecht.

MOORKENS, Th., 1972b. Foraminiferen uit het stratotype van het Montiaan en uit de onderliggende lagen van de boring te Obourg. (Met een overzicht van de stratigrafie van het Paleoceen van België). Natuurwetenschappelijk Tijdschrift, 54: 117-127.

MOORKENS, Th., 1982. Formanifera of the Montian stratotype and of subjacent strata in the "Mons well 1969" with a review of the Belgian Paleocene Stratigraphy. Toelichtende Verhandelingen voor de Geologische en Mijnkaarten van België, 17(2): 186 p.

MOURLON, M., 1873. La géologie. In Van Bemmel, E., Ed., Patria belgica, tome I: Belgique physique. Bruylant-Christophe, Bruxelles, p. 177-192.

MOURLON, M., 1880. Géologie de la Belgique, tome I: 1-317.

MOURLON, M., 1887. Sur une nouvelle interprétation de quelques dépôts tertiaires. Bulletin de l'Académie royale des Sciences, Lettres, série 3, 14: 15-19.

MOURLON, M., 1894-1895. Sur l'âge des sables qui, entre Aerschot et Watervliet, au nord d'Eecloo, séparent l'argile de Boom (Oligocène moyen) de l'argile sous-jacente à ces sables. Annales de la Société Géologique de Belgique, 22: 237-256.

Nederlandse Aardoliemaatschappij & Rijks Geologische Dienst 1980 - Stratigraphic Nomenclature of The Netherlands. Verhand. Kon. Ned. Geol. Mijnbouwkundig Genootschap, deel 32.

Neerdael, B., Vandenberghe, N., Bonne, A., Fierens, E., Laga, P., Manfroy, P. , 1981. Utilisation des diagraphies dans la détermination des caractéristiques lithologiques dans l'argile nde Boom et leur intérêt pour les corrélations dans l'argile. Réunion de travail sur le choix des sites des dépôts de déchets radioactifs dans des formations géologiques : OCDE/AEN, Paris 19-22 Mai 1981.

NIJS, R. & DE GEYTER, G., 1984. Het Kwartsiet van Tienen: petrografische ken-merken en gebruik als bouwsteen. Monumenten en Landschappen, Brussel, 5: 20-29.

NIJS, R. & DE GEYTER, G., 1985. De l'usage architectural et des caractères pétro-graphiques du tuffeau de Lincent. Bulletin de la Commission Royale des Monuments et des Sites, Bruxelles, 12: 59-69.

NOLF, D., 1970. Ichthyologische fauna uit de Formaties Mont-Panisel en den Hoorn (Belgisch Eoceen). Licentiaatsverhandeling, Rijksuniversiteit Gent, Gent, p. 1-122.

NOLF, D., 1972. Stratigraphie des Formations du Panisel et de Den Hoorn (Eocène belge). Bulletin van de Belgische Vereniging voor Geologie, 81: 75-94.

ORTLIEB, J. & CHELLONNEIX, E., 1870. Etude géologique des collines tertiaires du Département du Nord comparées avec celles de la Belgique. Quarré & Castiaux, Lille, p. 1-228.

ORTLIEB, J. & DOLLFUSS, G., 1873. Compte rendu de géologie stratigraphique de l'excursion de la société malacologique de Belgique dans le Limbourg belge le 18 et 19 mai. Annales de la Société Malacologique de Belgique, 8: 38-57.

PAEPE, R. & VANHOORNE, R., 1976. The Quaternary of Belgium in its relation-ship to the stratigraphical legend of the Geological map. Toelichtende Verhandelingen voor de Geologische en Mijnkaarten van België, 18: 1-38.

QUINET, G.E., 1966. Les mammifères du Landénien continental belge. Etude de la morphologie dentaire comparée des "carnivores" de Dormaal. Mémoires de l'Institut Royal des Sciences Naturelles de Belgique, 158: 1-64.

QUINET, G.E., 1969. Apport de l'étude de la faune mammalienne de Dormaal à la stratigraphie générale du Paléogène supérieur Européen et à la théorie synthétique de la molaire mammalienne. Mémoires de l'Institut Royal des Sciences Naturelles de Bel-gique, 162: 1-188.

RIJKSGEOLOGISCHE DIENST & NEDERLANDSE AARDOLIEMAATSCHAP-PIJ, 1980. Stratigraphic nomenclature of the Netherlands. Verhandelingen van de Koninklijke Nederlandse Geologisch en Mijnbouwkundig Genootschap, 32.

ROBASZYNSKI, F., 1978. Paléocène et Eocène inférieure de la région de Mons et du Nord de la France: arguments actuels de corrélation. Bulletin de la Société belge de Géologie, 87: 239-247.

ROBASZYNSKI, F., 1979. Gretaceous - Tertiary boundary events in the Mons Basin with remarks on the Danian and the Montian in this area. Proceedings Cret.-Tert. Boundary Events, Copenhagen, p. 143-150.

ROBASZYNSKI, F., 1981. Montian. In Stratotypes of Paleogene Stages. Bulletin d'Information Géologique du Bassin de Paris, Mémoire hors-série, 2: 181-200.

ROBASZYNSKI, F., 1988a. Formation de Ciply. In Maréchal, R. & Laga, P., Voor-stel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brussel, p. 25-27.

ROBASZYNSKI, F., 1988b. Formation de Mons. In Maréchal, R. & Laga, P., Voor-stel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brussel, p. 28-30.

ROBASZYNSKI, F., 1988c. Formation de Hainin. In Maréchal, R. & Laga, P., Voor-stel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brussel, p. 31-33.

ROMEIN, B.J., 1962. On the type locality of the Maastrichtian (Dumont, 1849), the upper boundary of that stage and on the transgression of a Maastrichtian s.l. in South-ern Limburg. Mededelingen Geologische Stichting, nieuwe serie, 15: 77-84.

RUTOT, A., 1873. Rapport au point de vue paléontologique de l'excursion entreprise le 18 et 19 mai 1873. Annales de la Société royale de Malacologie de Belgique, 8: 58-69.

RUTOT, A., 1881. Note sur les découvertes paléontologiques faites dans ces derniers temps aux environs d'Erquelinnes. Annales de la Société royale de Malacologie de Belgique, 16: 19-21.

RUTOT, A., 1882. Résultats de nouvelles recherches dans l'Eocène supérieur de la Belgique. IV. Résolution de la question du Tongrien et du Wemmelien. Création du système Asschien. Annales de la Société royale de Malacologie de Belgique, 17: 181-185 (Bulletin des Séances).

RUTOT, A., 1884. Explication de la feuille de Landen-Terrain Eocène. Musée Royale d'Histoire Naturelle de Belgique, Service Carte géologique Royal, p. 43-47.

RUTOT, A., 1886. La tranchée de Hainin. Annales de la Société Géologique de Bel-gique, 13: 126-132.

RUTOT, A., 1903. C.R. Exc. Sess. extraordinaire Soc. belg. Géol. Paléont., Hydrol. dans le Hainaut et aux environs de Bruxelles (23-27 août 1902). Bulletin de la Société belge de Géologie, 17: M.385-386 et M.421 (Leval-Trahegnies).

RUTOT, A. & VAN DEN BROECK, E., 1886a. Sur l'âge tertiaire de la masse princi-pale du tuffeau de Ciply et nouvelles recherches sur sa fixation. Annales de la Société Géologique de Belgique, 13: 2-13 et 94-98.

RUTOT, A. & VAN DE BROECK, E., 1886b. La géologie de Mesvin-Ciply. Annales de la Société Géologique de Belgique, 13: 197-259.

RUTOT, A. & VINCENT, E., 1879. Coup d'oeil sur l'état actuel de l'avancement des connaissances géologiques relatives aux terrains tertiaires de la Belgique. Annales de la Société Géologique de Belgique, 6: M69-155.

SCHMITZ, G. & STAINIER, X., 1909. La géologie de la Campine avant les puits des charbonnages. Deuxième note préliminaire. Le Landenien, le Heersien et le Montien de la Campine. Bulletin de la Société belge de Géologie, de Paléontologie et d'Hydro-logie, 23: P-V292-296.

SCHUMACKER-LAMBRY, J., 1978. Palynologie du Landénien inférieur (Paléo-cène) à Gelinden-Overbroek/Belgique. Relation entre les microfossiles et le sédiment. Laboratoire de Paléobotanie et de Palynologie (éditeur), Université de Liège, p. 1-157.

SLIMANI, H., 1994. Les dinokystes des craies du Campanien au Danien à Halem-baye , Turnhout (Belgique) et à Beutenaken (Pays-Bas). Toelichtende Verhandelingen voor de Geologische en Mijnkaarten van België, 37: 173.

SMITH, Th. & SMITH, R., 1995. Synthèse des données actuelles sur les vertébrés de la transition Paléocène-Eocène de Dormaal (Belgique). Bulletin van de Belgische Vereniging voor Geologie, 104: 119-131.

STAINIER, X., 1931. Le Montien et le Heersien du Hainaut, de la Campine et de la Hollande. Bulletin de la Société belge de Géologie, de Paléontologie et d'Hydrologie, 41: 10-35.

STEURBAUT, E., 1986. Late Middle Eocene to Middle Oligocene calcareous nanno-plankton from the Kallo well, some boreholes and exposures in Belgium and a de-scription of the Ruisbroek Sand Member. Mededelingen van de Werkgroep Tertiaire en Kwartaire Geologie, 23(2): 49-83.

STEURBAUT, E., 1988. The Ypresian in the Belgian Basin. In Centenary Field Guide to the Tertiary. Bulletin van de Belgische Vereniging voor Geologie, 96(4)(1987): 339-351.

STEURBAUT, E., 1992. Integrated stratigraphic analysis of Lower Rupelian deposits (Oligocene) in the Belgian basin. Annales de la Société Géologique de Belgique, 115(1): 287-306.

STEURBAUT, E., 1998. High-resolution holostratigraphy of Middle Paleocene to Early Eocene strata in Belgium and adjacent areas. Palaeontographica, Abt. A, 247(5-6): 91-156.

STEURBAUT, E. & NOLF, D., 1986. Revision of the Ypresian stratigraphy of Bel-gium and northwestern France. Mededelingen van de Werkgroep Tertiaire en Kwar-taire Geologie, 23(4): 115-172.

STEURBAUT, E & NOLF, D., 1989. The Stratotype of the Aalter Sands (Eocene of NW Belgium): stratigraphy and calcareous Nannoplankton. Mededelingen van de Werkgroep Tertiaire en Kwartaire Geologie, 26(1): 11-28.

STEURBAUT, E., DE CONINCK, J., NOLF, D. & VANDENBERGHE, N., 1999. The Albert Canal section at Gellik and the spatial and temporal relationship of the proximal facies of the Rupelian in Belgium. In Abstracts 7th Biannual Meeting RCNNS/RCNPS, September 20-23, 1999, Leuven, p. 32-33.

STEVENS, C., 1913. Etude du Landénien supérieur dans le Hainaut. Annales de la Société Géologique de Belgique, 41: M.5-21.

STREEL, M., BICK, H., FAIRON-DEMARET, M., SCHUMACKER-LAMBRY, J. & VANGUESTAINE, M., 1977. Macro- et microfossiles végétaux dans le contexte litho- et biostratigraphique du Sénonien - Paléocène de la rive gauche de la Meuse au Nord de Liège, Belgique. Livret-guide de l'excursion du 22 septembre 1977, sympo-sium "Apport des techniques récentes en Palynologie". Liège.

SUBGROUP LITHOSTRATIGRAPHY AND MAPS, 1980. In F. Kockel, compiler, A lithostratigraphic scheme for the NW-European Tertiary Basin. Newsletter Strati-graphie 8(3): 236-237.

TAVERNIER, R. & GULINCK, M., 1947. Les Roches argileuses de la Basse et Mo-yenne Belgique. Congrès 1947 - Section géologique. Centenaire de l'association des Ingénieurs sortis de l'Ecole de Liège, Liège, p. 277-282.

TEILHARD DE CHARDIN, P., 1927. Les Mammifères de l'Eocène inférieur de la Belgique. Mémoires Musée Royale d'Histoire Naturelle de Belgique, 36: 1-33.

THIELENS, A., 1871. Relation de l'excursion faite par la Société Malacologique de Belgique à Orp-le-Grand, Folx-les-Caves, Wansin et autres localités voisines. Annales de la Société royale de Malacologie de Belgique, 6: 39-72.

VAN ADRICHEM BOOGAERT, H.A. & KOUWE, W.F.P., 1997. Stratigraphic Nomenclature of The Netherlands, revision and update by RGD and NOGEPA. Med-edelingen Rijks Geologische Dienst, 50, Section I - Tertiary, 39 p. .

VAN BOVEN, A., 1998 - Evaluatie van de Carlo-Erba CHNS -analysator met toe-passing op de Boomse Klei. licentiaatsverhandeling K.U. Leuven ,geologie, 107p.

VANDENBERGHE, N., 1974. Een sedimentologische studie van de Boomse klei. Niet-gepubliceerde Doctorale verhandeling, Katholieke Universiteit Leuven.

VANDENBERGHE, N. 1978 - Sedimentology of the Boom clay (Rupelian) in Bel-gium. Verhand. Kon. Acad. België, Klasse der Wetenschappen, jg. XL, 1978, nr. 147, 137 p.

VANDENBERGHE, 1980 - L'argile de Boom dans le pays de Waas et la vallée du Rupel-Oligocène Moyen in Robaszynski,F & Dupuis, C. , Belgique Guides Géologi-ques Régionaux, Masson p 161-164.

VANDENBERGHE, N., 1988a. Formatie van Bilzen. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Di-enst, Brussel, p. 192-197.

VANDENBERGHE, N., 1988b. Formatie van Boom. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Di-enst, Brussel, p. 198-204.

VANDENBERGHE, N., 1988c. Formatie van Eigenbilzen. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Dienst, Brussel, p. 205.

VANDENBERGHE, N., 1988d. Formatie van Voort. In Maréchal, R. & Laga, P., Voorstel lithostratigrafische indeling van het Paleogeen. Belgische Geologische Di-enst, Brussel, p. 206-207.

VANDENBERGHE, N., HAGER, H., VAN DEN BOSCH, M., STRAELEN, A., LEROI, S., STEURBAUT, E., PRÜFERT, J. & LAGA, P., 2001. Stratigraphic Corre-lation by calibrated well logs in the Rupel Group between North Belgium, the Lower Rhine area in Germany and Southern Limburg and the Achterhoek in The Nether-lands. Aardkundige Mededelingen, 11.

VANDENBERGHE, N. & LAGA, P., 1986. The septaria of the Boom Clay (Rupe-lian) in its type area in Belgium. Aardkundige Mededelingen, 3: 229-238.

VANDENBERGHE, N., LAGA, P., VANDORMAEL, C. & ELEWAUT, E., 1990. The geophysical log correlations in the Ieper Clay sections in Belgium. In Dupuis, C., De Coninck, J. & Steurbaut, E., eds., The Ypresian stratotype. Bulletin van de Bel-gische Vereniging voor Geologie, 97(3-4)(1988): 437-440.

VANDENBERGHE, N., HERMAN, J., and STEURBAUT, E., 2002. Detailed analy-sis of the Rupelian Ru-1 transgressive surface in the type area (Belgium). In: K.Gürs (Ed.), Northern European Cenozoic Stratigraphy (Proceedings of the 8th Biannual Meeting of the RCNNS/RCNPS at Salzau Castle near Kiel, 2-7 October 2001), Flint-bek, Germany: Landesamt für Natur und Umwelt des Landes Schleswig-Holstein, Hamburger Chaussee 25, D-24220 Flintbek, Germany, 2002, pp. 67-81.

VAN DEN BOSCH, M., CADEE, M.C. & JANSSEN, A.W., 1975. Een noord-zuidprofiel door Oligocene afzettingen in de gemeenten Stevoort, Kozen en Sint-Truiden (België, provincie Limburg). Mededelingen van de Werkgroep Tertiaire en Kwartaire Geologie, 17(1): 17-40.

VAN DEN BROECK, E., 1881-1882. Exposé sommaire des observations et décou-vertes stratigraphiques et paléontologiques faites dans les dépôts marins et fluvio-marins de Limbourg, 16: 125.

VAN DEN BROECK, E., 1882. Réponses aux observations….p. VIII-XXIV. Note sur les levés géologiques….. p. LXXIV-XCVI. Note sur la position stratigraphique de sables grossiers et chocolatés…. p. CVIII-CXI. Annales de la Société royale de Mala-cologie de Belgique, 17 (partim).

VAN DEN BROECK, E., 1883a. Note sur un nouveau mode de classement et de no-tation stratigraphique des dépôts géologiques basé sur l'étude des phénomènes de la sédimentation marine. Bulletin du Musée Royale d'Histoire Naturelle de Belgique, 2: 341-370.

VAN DEN BROECK, E., 1883b. Explication sur la feuille de Bilsen pour les terrains oligocènes. Musée Royale d'Histoire Naturelle de Belgique, Service Carte géologique du Royaume de Belgique.

VAN DEN BROECK, E., 1884. Sur un faciès nouveau ou peu connu de l'argile supé-rieure rupelienne et sur les erreurs d'interprétation auxquelles il peut donner lieu. An-nales de la Société royale de Malacologie de Belgique, 19, troisième série, IV: 71-75.

VAN DEN BROECK, E., 1893. Coup d'oeil synthétique sur l'Oligocène belge et ob-servations sur le Tongrien supérieur du Brabant. Bulletin de la Société belge de Géologie, 7: 208-302.

VAN DEN BROECK, E. & RUTOT, A., 1883. Explication de la feuille de Bilsen. Musée royale d'Histoire Naturelle de Belgique, Service de la Carte Géologique du Royaume, 1883.

VAN SIMAEYS, 2004. Stratigraphic and Paleoenvironmental Analysis of the Rupe-lian and Chattian in their type regions : implications for Global Oligocene Chronostra-tigraphy. Doctoral thesis Geology K.U. Leuven 201p.

VAN SIMAEYS, S. & VANDENBERGHE, N. , 2006. - Rupelian. Geologica Bel-gica 9/1-2:95-101.

VAN STAALDUINEN, C.J., VAN ADRICHEM BOOGAERT, H.A., BLESS, M.J.M., DOPPERT, J.W.Chr., HARSVELDT, H.M., VAN MONTFRANS, H.M., OELE, E., WERMUTH, R.A. & ZAGWIJN, W.H., 1979. The geology of The Nether-lands. Mededelingen Rijks Geologische Dienst, 31(2): 9-49.

VAN STRAELEN, V., 1923. Observations sur le Néogène et l'Oligocène en profon-deur dans la Campine Limbourgeoise. Bulletin de la Société belge de Géologie, 33: 58-65.

VINCENT, E., 1873. Sur quelques fossiles receuillis dans les sables heersiens d'Orp-le-Grand. Annales de la Société royale de Malacologie de Belgique, 8: 44-45

VINCENT, E., 1887. Sur quelques coupes visibles sur le territoire de la planchette de Saventhem. Annales de la Société royale de Malacologie de Belgique, 22: 40-46.

VINCENT, E., 1889. Nouvelle liste de la faune conchyliologique de l'Argile Rupe-lienne. Annales de la Société royale de Malacologie de Belgique, 23: 38-40.

VINCENT, E., 1928. Observations sur les couches montiennes traversées au puits n°2 du charbonnage d'Eysden, près de Maeseyck. Bulletin de l'Académie royale de Bel-gique, Classe des Sciences, sèr. 5, 13: 554-568.

VINCENT, E., 1930. Mollusques des couches à Cyrènes (Paléocène du Limbourg). Mémoires Musée Royale d'Histoire Naturelle de Belgique, 43: 1-43.

VINCENT, E. & LEFEBRE, T., 1872. Note sur la faune laekenienne de Laeken, de Jette et de Wemmel. Annales de la Société royale de Malacologie de Belgique, 7: 49-79.

VINCENT, E. & RUTOT, A., 1878. Note sur l'absence du système Diestien aux envi-rons de Bruxelles et sur les observations relatives au système Laekenien. Annales de la Société Géologique de Belgique, 5: 55-66.

VINCENT, E. & RUTOT, A., 1879. Coup d'oeil sur l'état actuel d'avancement des connaissances géologiques relatives aux terrains tertiaires de la Belgique. Annales de la Société Géologique de Belgique, 6: 69-155.

WOUTERS, L. & VANDENBERGHE, N., 1994. Geologie van de Kempen. Een synthese. NIRAS, Brussel, p. 1-208.

 


NEOGENE LITHOSTRATIGRAPHIC UNITS (BELGIUM)

Pieter LAGA, Stephen LOUWYE & Stephane GEETS (compilers)

Laga, P., Louwye, S. & Geets, S., 2001. Paleogene lithostratigraphic units (Belgium). In Bultynck & Dejonghe, eds. Guide to a revised stratigraphic scale of Belgium, Geologica Belgica, Brussels.

ABSTRACT

The presented lithostratigraphy of the Neogene deals only with the formal lithostratigraphic units of formation rank or higher (groups). The names of the lower rank units (members and beds) are just mentioned without description or other information. This lithostratigraphy corresponds largely with the legend of the new series of geological maps of Belgium - Flanders Region on scale 1:50.000, edited since 1993.

KEYWORDS: Neogene, lithostratigraphy, southern North Sea Basin, Belgium.

1. INTRODUCTION

The occurrence of Neogene sediments is limited to northern Belgium, i.e., to the provinces of Antwerp, Limburg and the northern part of Brabant and East Flanders. They consist essentially of glauconitic sands with a varying clay admixture and are furthermore characterised by the abundant occurrence of shells, often in massive layers, and local decalcification. Basals gravels are present between the units. Deposition took place in a shallow marine to perimarine environment at the southern margin of the North Sea Basin. An overview of the sequence stratigraphy, biostratigraphy and geometrical relationships of the Belgian Neogene units is given by Vandenberghe et al. (1998). The Neogene of Belgium is lithostratigraphically divided into 9 formations. Three formations (Berchem Fm, Diest Fm and Bolderberg Fm.) are placed in the Miocene, six in the Pliocene (Kattendijk Fm, Kasterlee Fm, Lillo Fm, Mol Fm, Poederlee Fm and Kiezeloöliet Fm). No groups are defined. A subdivsion of the formations into members or layers is given. The occurrences of the neogene formations are illustrated in Figs. 1, 2 and 3.

2. NEOGENE LITHOSTRATIGRAPHY

2.1. Berchem Formation - Bc

Authors: De Meuter & Laga (1976).

Description: green to blackish, fine to medium fine, often slightly clayey, very glauconiferous sand; rich in shells, dispersed in the sediment or concentrated in subhorizontal, sometimes massive layers; locally decalcified; basal gravel more or less developed, consisting mainly of dark rounded flint pebbles.

Stratotype: temporary exposures of the excavations for the "E3 - Kleine Ring" motorway around Antwerp (the present number of the motorway is E17), from Antwerp - Zuidstation to Borgerhout - Rivierenhof.

Area: Antwerp province: subsurface exposures and borings to the north and east of Antwerp.

Members: the formation is divided in the Antwerp area into the Edegem Sands Mbr, the Kiel Sands Mbr and the Antwerpen Sands Mbr. In the Antwerp Campine area it is divided into the Antwerpen Sands Mbr. and the Zonderschot Sands Mbr.

Thickness: 100 m

Age: Late Aquitanian to Serravallian.

Remarks: the formation is also discussed by Cogels in Van Ertborn (1879), De Heinzelin (1955a), Huyghebaert & Nolf (1979), Louwye (2000), Louwye & Laga (1998), Lyell (1852), Nyst (1845, 1861a), Vanden Broeck (1876).

2.2. Bolderberg Formation - Bb

Authors: De Meuter & Laga (1976), after Dumont (1850).

Description: lateral succession from marine to continental sandy deposits; dark-green, medium fine, slightly clayey, often very micaceous, very slightly ligniferous, glauconiferous sand, fossiliferous in the lower part, passing into white, fairly coarse sand with lignite layers and glassy quartzite banks; basal gravel well developed with dark rounded flint pebbles and shark teeth.

Stratotype: outcrops of the road cuttings on the Bolderberg hill.

Area: exposures and deep borings of the western edge of the Limburg province; exposures on the hills around and to the south of Diest, Brabant province.

Thickness: 50 m, 285 m in the Roer valley Graben.

Members: the formation is divided into the Houthalen Sands Mbr and the Genk Sands Mbr.

Age: Late Aquitanian to Early Burdigalian.

Remarks: the formation is also discussed by de Heinzelin & Glibert (1957), Glibert (1945, 1952), Gulinck (1956, 1959, 1963), Hinsch (1952), Le Hon (1862), Leriche (1934), Mourlon (1898), Tavernier & de Heinzelin (1963), Vanden Broeck (1880).

2.3. Diest Formation - Di

Authors: De Meuter & Laga (1976), after Dumont (1839).

Description: grey green to brownish, at most coarse, locally clayey, glauconiferous sand often with sandstone layers; mainly without fossils, except the very local Deurne and Dessel Sands Members; well developed basal gravel with small rounded flint pebbles and locally with bone fragments and shark teeth.

Stratotype: exposures at the former town fortress of Diest.

Area: exposures on the hill tops of northeastern Brabant, southwestern Antwerp and western Limburg provinces; deep borings of the more northern parts of Antwerp and Limburg provinces.

Thickness: 70 m in the type locality, and up to 185 m in the middle of the deeply eroded channels.

Members: the formation is divided in the Deurne Sands Mbr (Antwerp area) and the Dessel Sands Mbr (Campine area).

Age: Tortonian - early Messinian.

Remarks: the formation is also discussed by de Heinzelin & Glibert (1957), Glibert & de Heinzelin (1955), Gulinck (1963), Laga & De Meuter (1973), Louwye & Laga (1998), Louwye et al. (1999), Nyst (1861b).

2.4. Kattendijk Formation - Kd

Authors: De Meuter & Laga (1976) after de Heinzelin (1955c).

Description: dark grey to green grey, fine to medium fine, glauconitic sand, slightly clayey; sometimes mottled by tracks, locally with an important amount of Ditrupa; shells dispersed in the sand and concentrated in one or more layers; basal gravel of rounded quartz and flints, together with sharks teeth, phosphatic nodules and rounded bones.

Stratotype: the outcrop of the Verbindingsdok, described in detail by Cogels (1874), between - 4.8 m and 1.0 m.

Area: region of Antwerp, the northern part of the Antwerp Campine and very probably the "Land van Waas".

Thickness: 7.5 m at the outcrop; 12.5 m in boreholes near the type locality. In the Campine area the thickness of this formation above the Diest Formation is very reduced (5 m, max. 10m).

Age: Early Pliocene.

Remarks: the formation is also discussed by de Cogels (1874), Halet (1931), de Heinzelin & Glibert (1957).

2.5. Kasterlee Formation - Kl

Authors: De Meuter & Laga (1976), after Dumont (1882).

Description: grey fine micaceous sand, without fossils, slightly glauconiferous, with lenses of micaceous clay; at the base micaceous fine sand, often very glauconitic, burrowed and mottled; at some places, a basal gravel of flints and rare silicified fossils; often hardly distinguishable from the underlying Diest Formation; the upper limit is also hardly distinguishable from the Mol Formation.

Stratotype: outcrops on the hills on the right bank of the Kleine Nete valley.

Area: southern part of the Antwerp Campine and the Limburg Campine; gradual transition to the Kattendijk Formation to the north.

Thickness: up to 15 m in the subsurface of the type locality. Possibly up to 40 m in the northeast of the Antwerp province.

Age: Zanclean to (early?) Piacenzian.

Remarks: the formation is also discussed by Halet (1935a).

2.6. Lillo Formation - Li

Authors: De Meuter & Laga (1976).

Description: grey, grey brown and light grey brown shelly sand, clayey in the lower part and with several shell layers; in the upper part gradual decrease of the clay content and the thick shell layers; in the uppermost part, gradual disappearance of the shells.

Stratotype: outcrop of the Tijsmanstunnel under the Kanaaldok between 3.00 m and 23.50 m depth.

Area: harbour district of Antwerp and the northern part of the Antwerp Campine; to the south of the Campine gradual transition in the Poederlee Formation.

Thickness: 23 m in the type locality; 25 m in the north of the Antwerp province, but increasing considerably just north of the state border in The Netherlands.

Members: the formation is divided in the Luchtbal Sands Mbr., the Oorderen Sands Mbr., the Kruisschans Sands Mbr., the Merksem Sands Mbr. and the Zandvliet Sands Mbr.

Age: Zanclean to Piacenzian.

Remarks: the formation is also discussed by Cogels (1874), de Heinzelin (1950a, 1950b, 1952, 1955a, 1955b, 1955c, 1963), de Heinzelin & Glibert (1957), Dumont (1839, 1850), Glibert (1957), Halet (1935b), Leriche (1912, 1927), Mourlon (1880), Vanden Broeck & Cogels (1877), Van Voorthuysen (1958), Vincent (1889).

2.7. Poederlee Formation - Pd

Authors: De Meuter & Laga (1976), after Vincent (1889).

Description: fine slightly glauconiferous sand, with small lenses of clay in the lower part; base with gravel of rounded quartz and flint pebbles, silicified carbonates (also called the Hukkelberg Gravel); upper part largely oxidised in the type region, sometimes limonitic sandstones with shell moulds.

Stratotype: tops of the hills north of Poederlee: iron sandstone layers.

Area: southern part of the Antwerp Campine.

Thickness: approximately 10 m in the type locality.

Age: late Pliocene.

Remarks: the formation is also discussed by Cogels & Van Ertborn (1881).

2.8. Mol Formation - Ml

Authors: De Meuter & Laga (1976), after Mourlon (1896).

Description: white pure, coarse and medium fine sand, sometimes lignitic and with some lenses of a micaceous clay; in the type region, lower part very slightly glauconiferous.

Stratotype: sandpits for the exploitation of glass sands.

Area: whole northeastern part of the Campine.

Thickness: 20 m in the Mol area, but up to 70 m and more east of the faults.

Age: late Pliocene.

2.9. Kiezeloöliet Formation - Kz

Authors: Doppert et al. (1975) after Fliegel and Stoller (1913).

Description: the formation consists of a wide variety of lithologies, all of fluvial and lacustrine origin. The lowest part consists of coarse grained sand, the Waubach Sand, the middle part predominantly of clay members often with lignitic horizons (the Brunssum II en Brunssum I Members) with a sand member in between (the Pey Member) and the upper part consists of fine to coarse grained sand with some clayey intercalations (the Jagersborg Member).

Stratotype: the type-section is in Germany (Fliegel & Stoller, 1913) in a former gravel pit at Duisdorf near Bonn. The type section for the Netherlands is the area of Waubach - Brunssum - Schinveld, where deposits are exposed in clay and gravel pits and have been studied in numerous wells.

Area: in Belgium, this formation name is only used for these deposits in the Roer valley graben, being the continuation of the Dutch part of the graben (Demyttenaere & Laga, 1988). The formation outcrops occur only northeast of the Feldbiss and Reppel faults (= the western limit of the Roer valley graben).

Thickness: up to 250 m

Members: the members are defined in the Netherlands (van Adrichem Boogaert & Kouwe, 1997) except the uppermost Jagersborg Member, approximately 45 m thick. Part of this member may be of Quaternary age (Sels, Claes & Gullentops, 2001)

Age: Tortonian, Messinian, Zanclean, Piacenzian and Gelasian

3. OVERVIEW AND SYMBOLS OF THE NEOGENE LITHOSTRATIGRAPHIC UNITS (Formations)

4. ACKNOWLEDGEMENTS

The authors thank the members of the National Subcommission for Tertiary Stratigraphy for their constructive contributions, which allowed the composition of this lithostratigraphic scheme. It should never have been possible to establish this lithostratigraphy without their continuous collaboration and common sense.

5. REFERENCES

COGELS, P., 1874. Observations géologiques et paléontologiques sur les différents dépôts rencontrés à Anvers lors du creusement des nouveaux bassins. Annales de la Société Malacologique de Belgique, 9: 7-32.

COGELS, P., 1879. In Van Ertborn, O., ed., Notes sur les formations géologiques des environs d'Anvers. Bulletin de la Société Géographique d'Anvers, 3: 346-350.

COGELS, P. & VAN ERTBORN, O., 1881. Coup d'oeil rétrospectif sur nos travaux et leurs résultats. Le fort de Lierre. La roche de Poederlé. Mélanges géologiques, 3: 61.88. De Backer, Anvers.

DE HEINZELIN, J., 1950a. Stratigraphie pliocène et quaternaire observée au Kruisschans. I. Analyse stratigraphique. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, 26(40): 1-38.

DE HEINZELIN, J., 1950b. Stratigraphie pliocène et quaternaire observée au Kruisschans. II. Conclusions. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, 26(41): 1-22.

DE HEINZELIN, J., 1952. Notes sur les coupes de l'écluse Baudouin, à Anvers. Bulletin de la Société belge de Géologie, 61: 106-108.

DE HEINZELIN, J., 1955a. Considérations nouvelles sur le Néogène de l'Ouest de l'Europe. Bulletin de la Société belge de Géologie, 64: 463-476.

DE HEINZELIN, J., 1955b. Deuxième série d'observations stratigraphiques au Kruisschans. Coupes de l'écluse Baudouin. II. Conclusions. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, 31(67): 1-40.

DE HEINZELIN, J., 1955c. Deuxième série d'observations stratigraphiques au Kruisschans. Coupes de l'écluse Baudouin. I. Analyse stratigraphique. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, 31(66): 1-29.

DE HEINZELIN, J., 1963. Symposium sur la stratigraphie du Néogène nordique, Gand 1961. Compte rendu des excursions: descriptions des affleurements. Mémoires de la Société belge de Géologie, série in -8°, 6(1962): 222-246.

DE HEINZELIN, J. & GLIBERT, M., 1957. Lexique stratigraphique international, 1, fasc. 4a VII. Centre National de la Recherche Scientifique, Paris.

DE MEUTER, F. & LAGA, P., 1976. Lithostratigraphy and biostratigraphy based on benthonic foraminifera of the Neogene deposits of northern Belgium. Bulletin de la Société belge de Géologie, 85(4):133-152.

DEMYTTENAERE, R. & LAGA, P., 1988. Breuken en isohypsenkaarten van het Belgisch gedeelte van de Roerdalslenk. Eerste resultaten van een seismisch onderzoek in het gebied van Poppel - Lommel - Maaseik. Belgische Geologische Dienst, Professional Paper 1988/4, nr. 234, 20 p. + bijlagen.

DOPPERT, J.W.C., RUEGG, G.H.J., VAN STAALDUINEN, C.J., ZAGWIJN, W.H. & ZANDSTRA, J.G., 1975. Lithostratigrafie: Formaties van het Kwartair en Boven-Tertiair in Nederland. In: ZAGWIJN, W.H. & VAN STAALDUINEN, C.J. (eds.): Toelichting bij geologische overzichtskaarten van Nederland: 11-56. Rijks Geologische Dienst, Haarlem.

DUMONT, A., 1839. Rapport sur les traveaux de la Carte Géologique pendant l'année 1839. Bulletin de l'Académie royale de Belgique, 6(2): 464-485.

DUMONT, A., 1850. Rapport sur la carte géologique du Royaume. Bulletin de l'Académie royale de Belgique, 16(1849): 351-373.

DUMONT, A., 1882. Mémoires sur les terrains crétacés et tertiaires préparés par feu A. Dumont pour servir à la description de la carte géologique de la Belgique, 2 éd. par M. Mourlon. IV. Terrains tertiaires, part 3: 1-702.

FLIEGEL, G. & STOLLER, G., 1913. Jungtertiäre and altdiluviale pflanzenführende Ablagerungen im Niederrheingebiet. Jahrbuch des Königlichen Preussischen Geologischen Landesanstaltes, 31: 227-257.

GLIBERT, M., 1945. Faune malacologique du Miocène de la Belgique. I. Pélécypodes. Mémoire du Musée royal d'Histoire Naturelle de la Belgique, 103: 1-262, 12 pl.

GLIBERT, M., 1952. Faune malacologique du Miocène de la Belgique. II. Gastropodes. Mémoires de l'Institut Royal des Sciences Naturelles de Belgique, 121: 1-197, 10 pl.

GLIBERT, M., 1957. Pélécypodes du Diestien, du Scaldisien et du Merxemien de la Belgique. Première note. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, 33(9): 1-40.

GLIBERT, M. & DE HEINZELIN de BRAUCOURT, J., 1955. La faune et l'âge miocène supérieur des Sables de Deurne. Bulletin de l'Institut royal des Sciences naturelles de Belgique, I. Description, 31(71): 1-27; II. Conclusions, 31(72): 1-12.

GULINCK, M., 1956. Note sur la formation des "Sables Chamois" (Néogène) de la région du Heysel. Bulletin de la Société belge de Géologie, 65: 227-229.

GULINCK, M., 1959. Sur l'extension, en Campine, des "Sables Chamois" du Heysel. Bulletin de la Société belge de Géologie, 68: 371-372.

GULINCK, M., 1963. Symposium sur la Stratigraphie du Néogène nordique, Gand 1961. Essai d'une carte géologique de la Campine. Etat de nos connaissances sur la nature des terrains néogènes recoupés par sondanges. Mémoires de la Société belge de Géologie, série in -8°, 6(1962): 30-39.

HALET, F., 1931. Coupe géologique des terrains que traversera le grand tunnel creusé sous l'Escaut à Anvers. Bulletin de la Société belge de Géologie, 41: 169-180.

HALET, F., 1935a. A propos des formations dites Casterliennes des environs d'Hérentals en Campine. Bulletin de la Société belge de Géologie, 45: 290-297.

HALET, F., 1935b. Les formations néogènes au Nord et à l'Est de la ville d'Anvers. Bulletin de la Société belge de Géologie, 45: 141-153.

HINSCH, W., 1952. Leitende Molluskengruppen im Obermiozän und Unterpliozän des Östlichen Nordseebeckens. Geologisches Jahrbuch, 63: 143-194.

HUYGHEBAERT, B. & NOLF, D., 1979. Otolithes de Téléostéens et biostratigraphie des Sables de Zonderschot (Miocène Moyen de la Belgique). Mededelingen van de Werkgroep Tertiaire en Kwartaire Geologie, 16(2): 59-100.

LAGA, P. & DE MEUTER, F., 1973. A foraminiferal fauna found in the lower Member of the Diest Formation of Borings of the Antwerp Kempen (NE-Belgium). Bulletin de la Société belge de Géologie, 81(1972): 211-220, 2 figs.

LE HON, H., 1862. Terrains tertiaires de Bruxelles, leur composition, leur classement, leur faune et leur flore. Bulletin de la Société Géologique de France, 2 sér., 19: 804-821.

LERICHE, M., 1912. Le Néogène des environs d'Anvers. Réunion extr. du 27 août au 6 sept. 1912. Bulletin de la Société Géologique de France, 4 sér., 12: 725-727.

LERICHE, M., 1927. Les couches de base du Scaldisien au nord d'Anvers. Bulletin de la Société belge de Géologie, 36: 52-57.

LERICHE, M., 1934. Sur la présence, dans le Brabant et le Petit-Brabant, du niveau à dents de Squales qui occupe, la base du Néogène en Campine. Bulletin de l'Académie royale de Belgique, Classe des Sciences, 5 sér., 20: 519-526.

LOUWYE, S., 2000. Shallow marine Lower and Middle Miocene deposits at the southern margin of the North Sea Basin (northern Belgium): dinoflagellate cyst biostratigraphy and depositional history. Geological Magazine , 137(4): 381-394.

LOUWYE, S. & LAGA, P., 1998. Dinoflagellate cysts of the shallow marine Neogene succession in the Kalmthout well, northern Belgium. Bulletin of the Geological Survey of Denmark, 45: 73-86.

LOUWYE, S., DE CONINCK, J. & VERNIERS, J., 1999. Dinoflagellate cyst stratigraphy and depositional history of Miocene and Lower Pliocene formations of northern Belgium (southern North Sea Basin). Geologie en Mijnbouw, 78: 31-46.

LYELL, C., 1852. On the Tertiary strata of Belgium and French Flanders. Part I : On the Pliocene, Miocene and Upper Eocene. Quarterly Journal of the Geological Society of London, 8(31): 277-370.

MOURLON, M., 1880. Géologie de la Belgique, t. 1. Terrain Mio-Pliocène. Hayez, Bruxelles, p. 261-282.

MOURLON, M., 1896. Les mers quaternaires en Belgique d'après l'étude stratigraphique des dépôts flandriens en campiniens et leurs relations avec les couches tertiaires pliocènes. Bulletin de l'Académie royale de Belgique, 3 sér., 32: 671-711.

MOURLON, M., 1898. Sur les dépôts tertiaires de la Campine limbourgeoise à l'Ouest de la Meuse. Bulletin de la Société belge de Géologie, 12: 48-58.

NYST, H., 1845. Description des coquilles et polypiers fossiles des terrains tertiaires de Belgique. Mémoire Couronnée et des Saventes étrangers de l'Académie royale de Belgique, in -4°, 17(1843): 1-697, 15 pl.

NYST, H., 1861a. Notice sur un nouveau gîte de fossiles se rapportant aux faluniennes du Midi de l'Europe, découvert à Edeghem, près d'Anvers. Bulletin de l'Académie royale de Belgique, 2 sér., 12: 29-53.

NYST, H., 1861b. Notice sur une nouvelle espèce de coquille fossile du genre Pecten, trouvée dans le crag noir d'Anvers, ainsi que sur un gisement à échinodermes, bryozoaires et foraminifères. Bulletin de l'Académie royale de Belgique, 2 sér., 12 (9 et 10): 198-202.

SELS, O., CLAES, S. & GULLENTOPS, F., 2001. Toelichtingen bij de Geologische Kaart van België, Vlaams Gewest, Kaartblad (18-10) Maaseik - Beverbeek 1:50.000, Afdeling Natuurlijke Rijkdommen en Energie en Belgische Geologische Dienst, Brussel: 50 p, 13 fig.

TAVERNIER, R. & DE HEINZELIN, J., 1963. Symposium sur la stratigraphie du Néogène nordique, Gand 1961. Introduction au Néogène de la Belgique. Mémoires de la Société belge de Géologie, série in -8°, 6 (1962): 7-28.

VAN ADRICHEM BOOGAERT, H.A. & KOUWE, W.F.P. (compilers), 1997. Stratigraphic nomenclature of the Netherlands, revision and update by RGD and NOGEPA: Section I - Tertiary - Sep. 1997. Mededelingen Rijks Geologische Dienst nr. 50: 1-39, annexes I 1 - I 6.

VANDENBERGHE, N., LAGA, P., STEURBAUT, E., HARDENBOL, J. & VAIL, P.R., 1998. Tertiary sequence stratigraphy at the southern border of the North Sea Basin in Belgium. In Mesozoic and Cenozoic Sequence Stratigraphy of European Basins, SEPM Special Publication 60: 119-154.

VANDEN BROECK, E., 1876-1878. Esquisse géologique et paléontologique des dépôts pliocènes des environs d'Anvers. Annales de la Société Malacologique de Belgique, 9: 1-371.

VANDEN BROECK, E., 1880. Observations nouvelles sur les sables diestiens et sur les dépôts du Bolderberg. Annales de la Société Malacologique de Belgique, 15: 85-90.

VANDEN BROECK, E. & COGELS, O., 1877. Observations sur les couches quaternaires et pliocènes de Merxem. Annales de la Société Malacologique de Belgique, 12: 68-74.

VAN VOORTHUYSEN, J.H., 1958. Les Foraminifères mio-pliocènes et quaternaires du Kruisschans. Mémoires de l'Institut Royal des Sciences Naturelles de Belgique, 142: 1-63.

VINCENT, G., 1889. Documents relatifs aux sables pliocènes à Chrysodomus contraria d'Anvers. Annales de la Société Malacologique de Belgique, 24: 25-31.

Figure 1: occurrence of the paleogene and neogene formations along a transect from the French - Belgian border to Woensdrecht.

Figure 2: occurrence of the paleogene and neogene formations along a transect from Kallo to the Maas river.

Figure 3: occurrence of the paleogene and neogene formations along a transect from Oostende to the Maas river.


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Date de dernière mise à jour : 23/1/2012 (21/11/2011)
Pétrologie sédimentaire, B20, Université de Liège, Sart Tilman, B-4000 Liège