GEOLOGICAL SOCIETY OF MANCHESTER. 



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is, however, from the similarity and geological connection subsisting 

 between the French formations and those of the British islands, that the 

 study of the former becomes of importance to the British geologist ; it 

 forms the complement of his previously acquired knowledge of his own 

 country's geological condition ; and, from its being of ready access, a 

 knowledge of it becomes almost indispensable. The object of the paper 

 was stated to be, to give only some general indications of the extent and 

 nature of the principal formations of France ; which were enumerated, 

 as follow, in a descending order, according to their dates, more or less 

 recent. 



1. Tertiary formations. — The basin of the Gironde, including a wide ex- 

 tent of country, on each side of the Gironde ; and all that extensive por- 

 tion of ancient Guienne and Gascony, known by the name of the Landes. 

 The tertiary basin of the delta of the Rhone, and the neighbourhood of 

 Aries. The Paris basin, which is divided into two not very unequal por- 

 tions, by the Seine; but is not so extensive as that of the Gironde. The 

 Lyons basin, including a long tract, through which the Saone flows ; and 

 also along the eastern bank of the Rhone, after its junction with that 

 river. The Strasburg basin, on the Rhine, between Basle and Mayence. 

 To these may be added part of the great tertiary formation of the Nether- 

 lands, in the immediate neighbourhood of Dunkirk ; but this can hardly 

 be comprised among the French formations, properly so called, however 

 closely connected with them it may be in a geological sense. 



2. Secondary formations. — The great chalk formation of the north of 

 France, including the greensand, and associated formations. Math gault, 

 wealden clay, etc. which surrounds the Paris tertiary basin ; and extends 

 through Normandy, Touraine, and Champagne, into Artois. A similar 

 formation, but on a much smaller scale, to the north of the basin of the 

 Gironde, extending from Saintonge into Perigueux ; another skirting the 

 Pyrenees, and a fourth to the east of the Rhone. The oohtic formations 

 of the Jura, which commence near Grenoble and extend, north-easterly, 

 to the neighbourhood of Strasburg on the Rhine. This is one of the 

 most important and best developed in France. The oolitic and other for- 

 mations above the carboniferous series, which intervene between the 

 chalk series of Normandy, and the primitive district of Brittany. A si- 

 milar series, which commences near Poictiers, and extends north-east- 

 ward through France, in an irregular manner to Metz, the Moselle, and 

 the Rhine. And another series, of the same kind, forming great part of 

 ancient Languedoc, and Provence, with a long tract, skirting the Pyre- 



