ORIGINAL ARTICLES. 
On Cycles of Sedimentation in the Eocene Strata of the 
Anglo-Franco-Belgian Basin. 
By L. Dupury Stamp, M.Sc., A.K.C., F.G.S., King’s College, London. 
(Continued from p. 114.) 
Ill. THE EOCENE SUCCESSION IN EACH AREA. 
AY Tan Paris! “Basi? 
The Eocene deposits of the Paris region group themselves naturally 
IML Six Cycles: —— 
Marine representatives. 
Caleaire de Ludes. 
Bartonian . ; 
Sables de Marines. 
Ledian (Auversian) _ . Sables d’Auvers (Sables moyens 
or Sables de Beauchamp). 
Lutetian  . : .  Calcaire grossier. 
Ypresian . : . Sables de Cuise. 
Landenian : . Sables de Bracheux. 
Montian . Calcaire pisolitique. 
The beds are see lonatineutl marine towards the north and pre- 
dominantly continental towards the south and south-east. At 
Verzenay,t near Reims, in the south-east, there is practically a 
complete succession of continental deposits from the Landenian to 
the Bartonian. 
The diagram (Fig. 2, p. 147) shows in more detail the grouping 
adopted for the Hocene beds of the Paris region. It is adapted from 
the work of Leriche, and is the grouping now generally accepted on 
the Continent.” 
Montian.—The Montian (Calcaire pisolitique) is now only found in 
a few isolated patches and seems to have been deposited in certain 
areas rather than over the whole Paris region. In some respects 
the fauna 1s intermediate between the Cretaceous and the Hocene. 
There are some curious anomalies in the situation of some of the 
deposits of this age, which tend to suggest localized formation in 
shallow lagoons left during the retreat of the Cretaceous sea. 
It is simpler, for this reason, to commence the diagram with the 
next cycle—the Landenian. 
Landenian.—The Lower or Marine Landenian consists of 
glauconitic sands, often argillaceous towards the base and tending 
to be harder in the lower part and to form beds of “ tuffeau”’ 
Glauconite becomes less abundant in the higher parts. The Lower 
Landenian has been divided into three zones :—* 
3. Zone of Cyprina scutellaria. 
2. Zone of Pholadomya Koninck. 
1. Zone of Cyprina Morris. 
1 Leriche, ‘“‘ Observations sur les Terrains tertiaires des environs de Reims 
et d’Epernay ’’?: Ann. Soc. géol. Nord, vol. xxxvi, 1907, p. 367. 
2 Compare Lemoine, Géologie du Bassin de Paris, 1911, p. 200. 
3 Leriche, “‘Sur les Horizons paléontologiques du Landénien marin du 
Nord de la France’’: Ann. Soc. géol. Nord, vol. xxxii, 1903, p. 239. 
