The stratigraphic division of the Rupel Clay in beds, Belgium

The stratigraphy of the Oligocene in Belgium is rather complex.
A summary was given by Glibert & de Heinzelin (1954b) and Glibert (1957), which is reproduced below.
Oligocene after Glibert and de Heinzelin
The divisions of the Oligocene in Belgium, after Glibert & de Heinzelin (1954b) and Glibert (1957).
The symbols are those of the Geological Map of Belgium.
Afterwards, the Grimmertingen Sand was transferred to the Late Eocene, together with the Lattorfian. However, after the indication
of a GSSP for the Eocene-Oligocene boundary at Massignano, near Ancona, Italy (Premoli & Jenkins, 1993) it became part of the Early Oligocene again.
The actual views are summarized by Marechal & Laga (1988) and Marechal (1991).
They divide the Oligocene in Belgium into the units, given in the table below.
Age: absolute age in 106 years; C.s.u.: chronostratigraphic units;
V.B.: province of Vlaams Brabant, A.: province of Antwerp, L. province of Limburg.
Palaeographic map Eearly Oligocene
The molluscan fauna from the Oligocene of Belgium was described by different authors.
Glibert & De Heinzelin (1954) studied the brackish water fauna from the provinces Limburg and Vlaams Brabantse and marine fauna's or the Rupelian, in which especially the Alde Biezen Sand (Rupelian, Atuatuca Formation, brackish and the Berg Sands (Rupel Formation, marine) contain a rich fauna. Furthermore they described the fauna of the Grimmertingen sand, which is now considered as Priabonian, but still Oligocene. Glibert (1957) studied the fauna of the Rupel clay proper, besides that of the Upper Oligocene Chattian from the coal mines of Limburg and the Campine area. This study, although very thorough, shows the characteristic lacks of the period in which it was written.
First, the stratigraphic position of the shells treated was not known yet. The stratigraphic division of the Rupel Clay in beds was only studied much later, by Vandenberghe (1978).
Furthermore, only material, collected on the surface was used, no sieved clay samples. Consequently, the smaller species remained unknown, while from the larger species the protoconchs were not collected.
The latest study, treating only pteropods, is from (1989). For these reasons, the ECCG started a systematic sampling of the different septarian horizons of the Rupel Clay.
Between the septarian layers clay horizons are present, which contain comparatively little calcitic material and very little shell material.
Furthermore, this clay is much more difficult to treat than the sandier material between the septarian nodules. This research yielded the fauna, which is given in table 1 and which consists of 63 species. 25 of these are new for Belgium; they were identified by comparison with the fauna of Malliss, Germany, described by Moths (2000).
It is significant that the most common molluscan species, the scaphopod Gadilina ottoi (Pilsbry & Sharpe, 1898), was found for the first time in the Oligocene of Belgium.

Table 1
Rupel clay
NewName S0S10S20S30S35S41S50S60
 Yoldia deshayesiana (Nyst, 1835)  x    xxxxx
xYoldiella p. pygmaea (von Münster, 1837)      x    xx  
xNucula sp.      x          
 Nucula duchasteli Nyst, 1835            x x  
xBathyarca bellula (Wiechmann, 1870)              x  
xNucinella dobergensis (Lienenklaus, 1891)      x    xx  
 Chlamys picta diomedes (d'Orbigny, 1852)      x          
 Pycnodonte paradoxa (Nyst, 1835)         x        
 Thyasira benedeni (De Koninck, 1835)            xx  
xThyasira obtusa (Beyrich, 1848)            xx  
xLucinoma borealis (Linnaeus, 1758) subsp.      x          
xMontacuta            x    
 Cyclocardia kickxi (Nyst, 1835)    x    x      
 Carinastarte kickxi (Nyst, 1835)  x              
 Arctica i. rotundata (Agassis, 1845)  x          x  
xHiatella arctica (Linnaeus, 1758)  x          x  
 Corbula gibba (Olivi, 1792) s.l.          xxx  
xThracia nysti von Koenen, 1868          x  x  
xCuspidaria clava (Beyrich, 1848)              x  
 Cardiomya kochi (Philippi, 1843)              x  
 Pholadomya puschi Goldfuss, 1837  x          x  
 Bivalvia: Total    515248141
 Solariella bernaysi Glibert, 1950              x  
xAlvania cf. rupeliensis Tembrock, 1969              x  
xPutilla sp.      x          
xCirsope multicingulata (Sandberger, 1868)              x  
xCirsope ovulum (Philippi, 1844)              x  
 Lunatia achatensis (De Koninck, 1837)          xxxx
 Arrhoges s. speciosus (Scholtheim, 1820)  x    x xxxx
 Charonia flandrica (De Koninck, 1837)          x  x  
 Ficus concinnus (Beyrich, 1856)              xx
 Echinophoria rondeleti (Basterot, 1825)              x  
 Eotyphis scalaris (Braun, 1850)              x  
 Hexaplex pauwelsi (De Koninck, 1837)              x  
 Liomesus danicus (Von Koenen, 1880)              x  
 Aquilofusus deshayesi (De Koninck, 1837)              x  
 Aquilofusus waeli (Nyst, 1852)              xx
 Streptolathyrus m. multisulactus (Nyst, 1843)          xxxx
 Fusinus elatior (Beyrich, 1856)              xx
 Streptodictyon soellingensis (Tembrock, 1965)              x  
 Babylonella fusiformis (Cantraine, 1835)            xx  
 Ancilla karsteni (Beyrich, 1850)                x
 Genota morreni (De Koninck, 1837)          x      
 Bathytoma crenata (Nyst, 1843)              xx
xAsperodaphne n. sp.              x  
 Turricula regularis (De Koninck, 1837)        x    xx
 Oxytropa konincki (Nyst, 1843)              xx
 Gemmula laticlavia (Beyrich, 1848)            xxx
 Fusiturris d. duchasteli (Nyst, 1843)        x    x  
 Fusiturris selysi (De Koninck, 1837)            xxx
 Fusiturris vervoeneni A.W. Janssen                  
xNiso incrassata (Von Koenen, 1867)              x  
x Cirsotrema cf. insigne (Philippi, 1843)            ?    
xAclis vetusta Wiechmann, 1871              x  
xOdostomia acutiuscula (Braun, 1850)              x  
xRingicula semperi Koch, 1860              x  
xCylichna laurenti (Bosquet, 1859)              x  
xCrenilabium terebelloides (Philippi, 1844)              x  
xPhiline kochi Von Koenen, 1880              x  
 Clio blinkae A.W. Janssen, 1989      x          
 Limacina hospes Rolle, 1821              x  
  Creseis sp.                  
 Gastropoda: Total    1022573312
xGadilina ottoi (Pilsbry & Sharpe, 1898)      x      x  
xGadila rupeliensis R. Janssen, 1989      x      x  
 Fissidentalium n. pseudacutum R. Janssen, 1989      x  x  x  
 Scaphopoda: Total    00301030
25Mollusca: Total   63616410165013
The samples came from three quarries, Wienerberger at Rumst, Argex at Kruibeke and SVK at St. Niklaas. Material from the other existing exposures will be collected in the future.
A study boring for the possibility of stocking radioactive material in the Campine area showed the Rupelian clay attain a much larger thickness (to several hundreds of meters). Material from this boring should be included in the research.
Furthermore, it can be concluded from the graph that the diversity in molluscan species becomes higher at the upper levels of the sections
The diversity increases from S41 onward and reaches a maximum at S50.
In the layers, belonging to the Terhagen Clay mainly isolated shells are found; in the lower part, Arctica islandica rotundata is typical; this species already starts below the Rupel Clay. Also Cyclocardia kickxi and Carinastarte kickxi seem to occur solely in the Terhagen Clay.
Typical is the pteropod Clio blinkae A. W. Janssen, 1989. After S30, in the Putte Clay, the diversity mounts strongly. Here occurs the pteropod Limacina hospes Rolle, 1821.
The highest number of species is reached in S50, but this is possibly an artefact, because S60 was sampled only perfunctorily.
The fauna is characterized by species, adapted to an oxygen poor environment, such as Thyasira.
In S41 and S50 not only adult shells occur, as in the underlying levels, but also protoconchs, so embryonic specimens. Apparently the fauna needed a long time span to develop a stable population, which could procreate at the actual locality were they were found.
Before, only isolated individuals were found which had possibly died in another environment.
Not only had the mollusca reached a maximal diversity in S50. The same applies to the other invertebrates. These included among others a brachiopode species, which is rather common, but possibly not yet described.
Furthermore, one bryozoan species occurs. Many fragments are found of the pelagic hydrozoan colony Delheidia, of which only seven complete specimens are known.
Very peculiar is the occurrence of insects. One Beetle was collected by J. Herman in S41, and another Beetle by L. Dufraigne in the "Red Layer". A Bug was collected by R. Marquet in S50. All fossils are pyritised. It is exceptional that continental animals are preserved in a holomarine environment. They occur in none of the Miocene or Pliocene deposits around Antwerp. For a similar conservation, an oxygen poor environment is required. It also points to the presence of land in the immediate vicinity, while the molluscan fauna is typical of deeper water, more than the Pliocene Kattendijk Formation, which seems deposited at 50 m or deeper.


Glibert, M. & De Heinzelin, J. 1954. L'Oligocène inférieur belge. Volume Jubilaire Victor Van Straelen I, Brussel, IRScNB. pp. 281-438.
Glibert, M., 1957. Pélécypodes et gastropodes du Rupélien supérieur et du Chattien de la Belgique. Institut royal des Sciences naturelles de Belgique, Mémoires 137: 1-98.
Janssen, A.W., 1989. Some new pteropod species from the North Sea Basin Cainozoic (Mollusca: Gastropoda, Euthecosomata). Mededelingen van de Werkgroep voor Tertiaire en Kwartaire Geologie 26 (3): 91-133
Maréchal, R. 1991. A new lithostratigraphic scale for the Paleogene of Belgium. Abstracts 3rd Biannual Joint Meeting Regional Committees on Northern Palaeogene and Northern Neogene Stratigraphy, Gent, 9-13 September 1991, 2 p., 1 fig.
Maréchal, R. & Laga, P., 1988. Voorstel Lithostratigrafische Indeling van het Paleogeen. Nationale Commissies voor Stratigrafie, Commissie Tertiair, Belgische Geologische Dienst, Brussel, 208 pp.
Moths, H., 2000. Die Molluskenfauna im Rupelton der Ziegeleitongrube Malliss im Wanzeberg (südwestl. Mecklenburg-Vorpommern). Malliss, Regionalmuseum. 103 pp.
Premoli Silva, I. & Jenkens, D.G., 1993. Decision on the Eocene-Oligocene boundary stratotype. Episodes, 16(3): 379-382.
Vandenberghe, N., 1978. Sedimentology of the Boom Clay Formation, Belgium. Bulletin van de Belgische Vereniging voor Geologie 102 (1-2): 5-77.