198 On the Position of Salifcroiis Bocks 



On comparing what is above said with other well-known 

 sections of the strata immediately below the chalk, the follow- 

 ing conclusions appear to be warranted. 



1st, That the green and gray sand of Havre is perfectly 

 identical with the green-sand of Warminster, contains simi- 

 lar subordinate masses of chert, incloses the same charac- 

 teristic fossils (Siphonise, Galerites, Pectinidee, and Terebra- 

 tulae), and lies in the same geological position, immediately in 

 contact with the lower chalk. 



2ndly, That the series of strata observable at Havre below 

 the green-sand is very similar to the great clay formation of the 

 Vale of Pickering in Yorkshire, of which the upper part ap- 

 pears analogous to the gault, while the lower part is decidedly 

 Kimmeridge clay, no trace of the Portland oolite or wealden 

 formation being visible in either district. Whether any por- 

 tion of the ferruginous sands observed in great confusion at 

 Havre belongs to the lower green-sand, I cannot undertake 

 to decide. 



Srdly, That the manner in which the fossils are disposed 

 in the Kimmeridge clay at Havre, is extremely like what 

 obtains in North Wilts and in Yorkshire ; the shells being 

 most plentiful towards the bottom of the deposit, and accom- 

 panied by partial layers of stone, which indicate the proximity 

 of the coralline oolite formation beneath. As near Wotton 

 Basset in Wilts, at Heddington near Oxford, at Brickhill in 

 Buckinghamshire, at Welton, Elloughton, Malton, Helmsley, 

 and Kirby Moorside in Yorkshire, the flat oysters (Ostrea 

 deltoidea, Sot):.) lie in a continuous layer parallel to the strati- 

 fication, enveloped in pale blue clay, and unmixed with other 

 shells. 



XXX. On the Position of Rocks ifi the Geological Series, 

 whence the Salt Bri?ie is derived, in the State of New York, 

 North America. By A Correspondent. 



A CORRESPONDENT, adopting the signature E. W. B,, 

 ■^^ in the Phil. Mag. and Annals of Philosophy for July 

 1S29, page 75, decides, without personal inspection, and at a 

 distance of more than three thousand miles from the beds, that 

 a particular saliferous rock, because it contains brine springs 

 and cavities of old crystals of salt, " is in reality the equivalent 

 of the new red sandstone." And he imputes to Mr. Feather- 

 stonhaugh the error of supposing it to be the old red, on ac- 

 count of the contiguity to each other of the new and old red 



sandstone 



