CHAPTER XII. 



THE CRETACEOUS GROUP. 



Chalk, Craie of French ; Kreide of German Authors ; Chalk-Marl, English ; 

 Craie-Tufau, French ; Kreide-Mergel, German ; Greensand, English : 

 Glauconie-Crayeuse-Sableuse, French J Chloritische Kreide, Griinsand, 

 German. 



MUSEUMS : Geological Society, Collection of Dr. Mantell in the British 

 Museum ; that of Mr. Bowerbank, Mr. Saul, Mr. Dixon, of Worthing, 

 Mr. Purdue, and many Private Collections in the Southern and Eastern 

 Counties, Yorkshire, &c. &c. 



AUTHORS : Lyell, Mantell, Dixon, Fitton, Phillips, Woodward, Boblaye, 

 Virlet, D'Orbigny, Roemer, Reuss. 



CHARACTERISTICS : First of the Secondary Formations ; Marine; the Bed of 

 an Ancient Sea, Containing Marine Plants, Corals, Shells, Fishes and 

 Reptiles. 



THE chalk constitutes the boundary of the secondary rocks; 

 it formed the bed of a primeval ocean, of great extent, whose 

 spoils have largely contributed to the formation of our 

 existing islands and continents. 



SUBDIVISION. The following Table exhibits the different 

 stages of this period and their foreign equivalents : 



English Authors. French Authors. Eoemer. D'Orbigny. 



I Chalk \vith"l -, . , ., T ,, ^ . 



. . > Craie. Obere Kreide. L etage Uamen. 



flints. J 

 C ""} Un,ere Krei de. Senonieo. 



Chalk marl. Craie Tufau. Planer. Turonien. 



*: f ^and 2 *" I Glauconie Crayeuse. Grunsand. Cenomanien. 



| -{ Gault. Gait. Albien. 



j > Glauconie Sableuse. Quader. r Aptien. 



Hilsconglomei-at. I Neocomicn. 



