390 



ORDER OF SUPERPOSITION OF 



TABLE II. continued. 



Periods and 

 Groups. 



Names of the principal Members and general Mine- 

 ral nature of the Formation. 



Some of the Localities where the 

 Formation occurs. 



CalcaireGrossier (a), 

 plastic clay, sands, 

 sandstones, &c., with 

 marine fossils 6. 



Calcaire siliceux 

 sandstones and conglo- 

 merates, red marl,green 

 and white marls, lime- 

 stone, gypseous marls, 

 with land and fresh- 

 water fossils (c). 



a. Paris hasin. 



b. Paris, London, and 

 Hampshire basins, Isle 

 of Wight. 



c. Paris Basin, Isle of 

 Wight, Auvergne, Ve- 

 lay, Cantal. 



1. MaestrichtBeds. Earthy white 

 limestone with siliceous masses, re- 

 sembling chalk (marine). 



2. Chalk with fonts (marine). 



3. Chalk without flints (marine). 



4. Upper green sand (marine). 

 Marly stone, and sand with green 

 particles; layers of calcareous sand- 

 stone. 



5. Gault (marine). Blue clay,with 

 numerous fossils, passing into calca- 

 reous marl in the lower parts. 



6. Lower green sand (marine). 

 Grey, yellowish, and greenish sands, 

 ferruginous sands and sandstones, 

 clays, cherts, and siliceous limestones. 



St. Peter's Mount, Maestricht. 



North and South Downs, and 

 parts of the intervening Weald of 

 Kent, Surrey, and Sussex. 



Isle of Wight, coasts of Hamp- 

 shire and Dorsetshire, Yorkshire, 

 North of Ireland. 



G 



1. Weald clay (freshwater). Clay, 

 for the most part without intermix- 

 ture of calcareous matter, sometimes 

 including thin beds of sand and shelly 

 limestone. 



2. Hastings sands (freshwater). 

 Grey, yellow, and reddish-brown 

 sands, sandstones, clays, calcareous 

 grits passing into limestone. 



3. Purbeck beds (freshwater). Va- 

 rious kinds of limestones and marls. 



1, 2. Extensively developed in the 

 central parts of Kent, Surrey, and 

 Sussex. 



3. Isle of Purbeck, in Dorset, 

 shire. 



