46 



A. BLTTT. 



[No- 1. 



Marl and Molasse, Sables de Fontenaye, marine, 3 alternations. 

 Arc 7'. 



Meulieres de Montmorency, Calcaire de Beauce (p. p.), fresh- 

 water. Between the arcs 7' and 8'. 



There is only a single irregularity: the arc 16, whose apex 

 ought to correspond to the marine bed in the middle of the 

 Calcaire de St. Ouen, does not reach so high, that we could ex- 

 pect a covering by the sea. But the oscillation is yet, at any 

 rate, indicated in Stockwell's curve, too, and the marine formation I 

 consists of a single layer, and is so little prominent that it has 

 only lately been distinguished. 



Another profile, from another situation, in the Basin of 

 Paris (la Frette, Bull. Soc. Geol. Fr. 1876, p. 471 ff.) has the 

 same number of alternations as the previous one, and extends 

 from 13 to 2'. The marine layer at 16 has not been pointed 

 out in this profile, otherwise the same oscillations are indicated. 



The profile from Mery-sur-Oise has, altogether, 71 alterna- 

 tions of which 25 are in the Calcaire grossier. A great part of 

 the calculated curve is therefore filled out, in respect of 37 al- 

 ternations, without any gap in the series of beds At arc 7', the 

 marine formations of the basin become closed. In the Miocene 

 epoch volcanic eruptions took place in Auvergne. 



These oscillations of the beach-line have not been confined 

 to the Basin of Paris. The series of beds in the Basin of the 

 Gironde; which, by means of the Atlantic Ocean only, seems to 

 have been connected with the Basin of Paris; are (according to 

 Vasseur: Ann. Sc. Geol. Vol. XIII, p. 398 ff.): the Tertiary for- 

 mations begin with the middle Eocene, Nummulitic sand and 

 coarse lime-stone, marine. After that, upheaval of the land and 

 erosion. After that a rising of the sea took place: clay con- 

 taining Ostrea cucullaris (arcs 14-15). Then an upheaval again: 

 Calcaire lacustre de Plassac, and along with it Calc. saumatre 

 de Begadan (16-10. Then a fresh rising of the sea: Calcaire 

 marin de St. Estephe and Calcaires et Marnes a Anomia Giron- 

 dica (2'— 40. Upheaval and erosion. Mollasse (freshwater) de 

 Fronsadais (6'?). Sea rising: Calcaire a Asteries de Bourg 



