206 



THE GEOLOGIST. 



" The Tertiaries of Bigorre consist entirely, in the valley we have 

 named, of a lacustrine deposit, formed at the foot of the Pyrenees 

 after the last rising of the land ; and do not offer at any point the 

 smallest indication of an upheaving force. 



" This deposit in the first instance formed a table-land extending 

 from the foot of the mountains ; but this has since been divided by 

 the diluvium streams into strips, as it were, now found separated by 

 the valley of the Adour, and numerous dales. 



" In the region which occupies us in the present paper, the tertiaries 

 follow the bend of the hill between Bagneres and Louides, and an 

 outlying prominence, whose elevation was too great for the tertiary 

 waters to cover. 



" For this reason, on either side of this hill, we see the tertiaries 

 commence by two beds which cover and level the cretaceous schists 

 and overlying beds, pierced and diversified by granite and ophites, 

 which never, however, reach the surface. 



" One of these beds begins at Bagneres, but only on the right side 

 of the Adour, whence it extends to the east to join itself to the plain 

 of Launemezan. 



" The other commences not far from Lourdes, to the left of the 

 valley of Ade. They leave between them the hill above mentioned, 

 which is entirely uncovered by these deposits. 



" A little to the north of Montgaillard (Vieille Ossun), near the 

 plain of Tarles, one sees the outliers of the Pyrenees represented by 

 the conglomerate of Palasson, dip under the tertiaries in such a manner 

 that from this limit all the hills in the valley are composed of it." 



PROCEEDINGS OF GEOLOGICAL SOCIETIES. 



Geological Society oe London, — March 6, 1861. 



1. "On the Succession of Beds in the Hastings Sand in the Northern 

 portion of the Wealden Area." By F. Drew, Esq., F.G.S., of the Geological 

 Survey of Great Britain. 



Having first referred to the division of the Wealden beds by former authors 

 into the " Weald Clay," the " Hastings Sand," and the " Ashburnham Beds," 

 and I lie subdivision of the "Hastings Sand" by Dr. Mantell into "Horsted 

 Sands," " Tngate Beds," and " Worth Sands," and having defined the district 

 tinder notice as King between and in the neighbourhood of the towns of Ten- 

 terden, Cranbrook, Tunbridge, Tunbridge Wells, East Grinstead, and Horsham. 

 Mr. Drew proceeded to describe, first, the several beds in the meridian and 

 vicinity of Tunbridge Wells. The Weald Clay is at least six hundred feet 

 I hick in I his district, and is underlaid by sands and sandstones, termed by the 

 author the " Tunbridge Wells Sand," on account of its being well exposed 

 there. This subdivision is about one hundred and eighty feet thick, and was 

 described in del ail; an important feature being the "rock sand," or massive 

 Sandstone forming the picturesque natural rocks of that neighbourhood, The 



