76 Mr. De la Heche on the Geologi; of Part jf France. 



found between the chalk and the blue marl and marlstone : I did not observe 

 any iron sand at that place. 



To the westward of Henqueville, the next hill, at Benerville, has no green 

 sand, its summit being- formed of coral rag : but the cliff between Villers sur 

 Mer and Dives, usually called the Vaches Noires*, is capped by it ; the green 

 sand resting partly upon coral rag, and partly upon beds of oolite, above a thick 

 blue clay (Oxford clay). 



The green sand formation does not appear upon the coast to the west of the 

 Vaches Noires, but it extends inland along the upper part of the hills from 

 Trouville sur Mer. Along this tract however it loses the usual character of 

 this bed, the prevailing rock being a loose siliceous sand with nodules of blue 

 limestone or chert disposed in layers. At the subterranean quarries near 

 Lisieux, a shaft is cut through this rock to a thick bed of whitish soft calca- 

 reous sandstone, under which is another bed of siliceous sandstone with no- 

 dules of limestone and cliert ; the whole rests upon oolite, as may be seen at 

 the bottom of the valley between Lisieux and Glos. Near the latter place 

 there is a quarry, at the top of which a loose siliceous and ferruginous sand 

 presents itself, containing large nodules of gray siliceous sandstone ; to this 

 succeeds siliceous sandstone containing organic remains; then a stratum, nine 

 inches thick, of compact gray limestone ; and under it a siliceous sandstone bed, 

 which rests upon a large-grained oolite. 



The hilly country, comprehended between the chalk district and a line 

 drawn south-east from Dives to Etreez, is composed of green sand, resting 

 either upon the marl and marlstone which forms the base of Cap la Heve, or 

 upon some member of the oolite formation. But many beds of the green 

 sand formation, which occur inland, do not extend to the coast. 



Blue Marl and Marlstone. 



This formation, which has been mistaken for lias, from its general resem- 

 blance to that rock, contains fossil crocodiles f at Havre, and near Cap la Heve a 

 bed of oysters. These, with the exception of an imperfect cast of an univalve, 



* The name Vaches Noires is properly applied only to the large fallen blocks, blackened by 

 sea-weed : these blocks are very dangerous to coasting vessels. 



t M.Cuvier, who has described these remains, has been misinformed in the statement, that the 

 same marl extends under the Vaches Noires cliffs ; for between the latter and the Havre marl 

 there occur several members of the oolite formation, such as thick beds of coral rag, oolite, &c. 

 as may be observed at Henqueville cliff, and at the hill between the river Toucques and Benerville. 



