ON THE MOVEMENTS OF THE EAKTu's CRUST. 3~)5 



As a startiug-point I will take the profile of the Paris basin*, which 

 I will endeavor to join on to recent times. Afterwards I will refer to 

 the lower and middle parts of the Eocene period. 



The section of the Paris basin about Mery-sur-Oise {Bull. 8oc. Geol. 

 Fr. 1878, pp. 243 ct seq.) shows the following oscillations and alterna- 

 tions of strata, and may, as regards the continuous portion, fit into 

 Stock well's curve, as appears from the arc numbers cited for each oscil- 

 lation : 



Sables de Guise, marine. 



Calcaire grossier inferieur et moyen, marine, with seven alter- 

 nations. 



Calcaire grossier; Caillasses a Oerithium, two marine alterna- 

 tions, and between them a deposit with fresh- water shells. 



Calcaire grossier ; Caillasses a Lucina, marine, with five alter- 

 nations. 



Calcaire grossier ; Caillasses a Cardium, marine, with eleven 

 alternations. Gap in the series. 



Sables de Beauchamp, fresh water and marine, about four alter- 

 nations. Arcs 14-15. 



Calcaire de St. Ouen, fresh water, four above which a marine de- 

 posit (summit of arc 16), then six fresh-water alternations. 

 Arcs 15 to 2'. 



Gypsum, marine, a))out eleven alternations. Arcs 2' to 4'. 



Gypse palustre, fresh water, about six alternations. Arc 5'. 



Marine verte, brackish, two alternations. Arc 6'. 



Calcaire de Brie, fresh water, one alternation. Between arcs 6' 

 and 7'. 



Marne et Mollasse, sables de Fontenaye, marine, three alterna- 

 tions. Arc 7'. 



Meulieres do Montmorency, Calcaire de Beauce (p. p.), freshwater. 

 Between arcs 7' and 8'. 



There is only one discrepancy : Arc 10, the summit of which should 

 correspond to the marine deposit in the middle of the Calcaire de St. 

 Ouen, does not go so high that we should expect an inundation of the 

 sea. But the oscillation is at any rate also indicated in StockwelFs 

 curve, and the marine formation consists of a single bed, and is so faintly 

 marked that it has only recently heen recognized. 



Another profile from another place in the Paris bnsin (la Frette, Bull. 

 8oc. Goel. Fr. 1876, pp. 471 et seq.) has the same number of alternations 

 as the above, and extends from 13' to 2'. The marine bed at 16 is want- 

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



The profile at Mery-sur-Oise has in all seventy-one alternations of 

 strata, of which twenty-five are in the Calcaire grojsier. A great part 



'' This section is given in my memoir on Alternationa of Strata, 



