30 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



The sands and gravels are limited to about 1 70 yards on either side 

 of the Tunnel, and have an anticlinal arrangement, the beds dipping 

 irregiilarly north and south. In one instance the gravel dips 15° to 

 the west. 



In the sand and gravel beds there were found but very few shells, 

 which were principally Gryphcece, and a few Belemnites ; but in the 

 lowest gravel-bed the fossils were more numerous, consisting chiefly 

 of Ammonites, Belemnites, Gryphcece, SerpulcB, &c., all bearing the 

 appearance of being much water-worn. This bed is composed of 

 fine and loose gravel, like shingle ; and there is but very little sand 

 with it*. 



The beds of red clayf are non-fossihferous, but contain large de- 

 tached blocks of Marlstone, of a bluish colou.r and of uneven fracture, 

 and vpith the edges very much rounded by attrition. On their surface 

 I found various impressions and casts of shells ; the most numerous 

 was the Cardium truncatum ; there were also Pecten, Trochus, Leda, 

 Ammonites planicostatus, &c. On breaking up the blocks, many of 

 them exhibited the remains of Fucoids. 



The gravel, sand, and clay seem to have formed the bed of a chan- 

 nel communicating between the Moreton and Evesham Valleys, having 

 Dover's and Campden Hills to the west, and Ebrington Hill to the east. 



The upper beds of the Lower Lias Shale :]; lie immediately under- 

 neath the lowest bed of red clay, the Marlstone-beds having been en- 

 tirely removed in this place by denudation ; the only remains of the 

 latter are the detached blocks, before-mentioned, lying in the beds of 

 red clay. 



The shale was sufficiently hard in some cases to require blasting, 

 but generally speakmg it was easily removed, being very wet§ and 

 full of joints, and requiring the greatest care in working. When 

 brought to the surface and exposed to the air, the shale soon 

 mouldered into a bluish clay, which was found serviceable for making 

 the bricks used in casing the Tunnel. 



The fossils found in excavating the Tunnel were, with some few ex- 

 ceptions, in a very imperfect state of preservation, and great care was 

 requisite to prevent their falling to pieces. On some of the Arcce, 

 and one or two other shells, when first excavated, I perceived con- 

 centric bands of a brownish colour, which disappeared on exposure to 

 the air. Many of the blocks of shale were covered with two or three 



* Great difficulty was experienced in sinking through the thick beds of running 

 sand, on account of the immense quantity of water they contained. Straw was 

 used to keep the sand from running out with the water while the miners were 

 fixing the timber ; the straw has since become incrusted with the carbonate of 

 lime, forming a solid mass between the planking and the sand-bed. 



t The tenacity of the red clay is such, that when a small part of the Tunnel 

 gave way, and the shale, being unsupported, fell in in a few hours, leaving a 

 superficial area of red clay 12 feet square, the clay retained its position for three 

 days, supporting the superincumbent gravel and sand ; after which time however 

 it broke, causing an immediate settlement on the surface. 



X There was not a trace of the Upper Lias beds met with during the excavation. 



§ Intermittent springs occureed in the shale. 



