lO THE EOCENE BEDS 



Seciion at Sinceny. 

 9. Vegetable earth. 



8. Massive beds of Ostrea hellovacensis and 0. sparnacensis. 

 7. Coarse sand in irregular beds, oblique, with rolled black pebbles, 



fossiliferous. 

 6. Grey plastic clay. 



5. Lignitic clay, stratified with iron pyrites and gypsum. 

 4. Brownish clay. 

 3. Bed of black rolled pebbles. 

 2. Calcareous white and green clay, white or grey sands in pockets, 



and white, magnesian rounded nodules very abundant, 



irregularly distributed, sometimes forming the entire mass of 



the deposit. 

 I. Fine white sand, slightly glauconitic, base not visible. 



Of these, i is a memlDer of the lower glauconitic sands ; 2 has 

 much analogy with the marls and limestones of Rilly ; 3 is a pebble 

 bed at the base of the Lignites ; 4, 5 and 6 are the Lignites of the 

 Soissonnais ; whilst 7 is the typical fossiliferous horizon of Sinceny, 

 and 8 a local oyster bed of the same deposit. The precise posi- 

 tion of these beds with reference to the formation above them is 

 easily determined, as the '■'■Sables de Cuise" crop out close by, 

 near the village. 



The sands of Sinceny contain nearly all the fluvio-marine 

 species of the Lignites, such as Potamides funatiis, Neritina 

 globulus, Planorbis heinisfomn, Melania inquinata, Axincea terebrat- 

 ularis, Corbicula cuneiformis and C. tellinella. A few species are 

 peculiar to the deposit and some pass into the " Sables de Cuise." 



Sands of the same age are also met with at many points in the 

 vicinity of Compiegne, Abbecourt, Brasles, &c. 



9. SANDS OF THE SOISSONNAIS. 



The nummulitic Sands of the Soissonnais, so called from their 

 maximum and typical development in the neighbourhood of 

 Soissons, rest on the Lignites of Soissons, or in certain localities on 

 the Sands of Sinceny, and they are overlaid by the Calcaire 

 Grossier. 



Geographically the beds of this formation are confined to the 

 north-east of the Paris basin; they disappear before attaining 

 Rheims and Epernay, and, as a rule, do not reach as far south as 

 the Seine ; they are bounded on the west by a line near Gisors 

 and stretch thence in a north-easterly direction towards Laon. 



In the valley of the Aisne these beds attain a thickness of over 

 160 feet ; they are usually composed of fine yellow or brown sands 

 with green grains (usually referred to as glauconite) in the lower 

 beds, but in the middle portions they become more lignitiferous 

 and argillaceous. - 



Two horizons have been recognised in these sands, viz.,* 



Upper : Sables de Cuise. 



\ .ower : Sables d'Aizy. 



* See Appendix II. 



