of the Birmingham and Gloucester Railway. 553 



§ 4. Marine erratic gravel without flints . — ^This detritus occurs at intervals along 

 the railway from Birmingham till the line approaches the valley of the Avon. Vast 

 accumulations of it (the "Northern drift" of Mr. Murchison) occur on all sides 

 of Birmingham. My own personal inquiries addressed to resident geologists, rail- 

 way engineers and excavators, aided by printed queries circulated in the Geological 

 Section of the British Association^ at Birmingham, all tend to prove the utter 

 absence of mammalian remains in the deposits of this class in that neighbourhood. 

 Chalk flints, though not absolutely wanting in the Birmingham gravel, are yet so 

 extremely rare, as to prove that the current which transported it came from the 

 north, and not from the east, and furnish a well-marked distinction from the flinty 

 gravel described below. 



At Mosely the railway is cut through a vast deposit of this gravel upwards of 

 eighty feet thick, reposing upon red marlf. It is composed of rolled pebbles, 

 rarely exceeding four inches in diameter, of various granitic and quartzose rocks 

 and altered sandstones, imbedded in clean ferruginous sand devoid of argillaceous 

 matter. A stratum of sand about thirty feet thick, free from pebbles, occurs in 

 the middle of the gravel. 



Between Mosely and the Lickey the railway-line is in general free from gravel. 

 The only mass of stone of sufficient size to deserve the name of an erratic block 

 occurred on the line of the railway between Cotteridge and WytchallJ, and re- 

 poses on the red marl. It is shapeless, about five feet by four, with the angles 

 partially rounded, and consists of greyish porphyritic trap. 



Patches of gravel of this class occur on each flank of the Lickey ridge, though 

 none, as before shown, were found on its summit at the part traversed by the 

 railway. The singular manner in which the gravel reposes on an irregular surface 

 of new red sandstone is shown in the cutting at the summit of the inclined plane, 

 PL XLVIII. fig. 1. This superficial drift closely resembles the genuine new red 

 conglomerate seen in the cutting on the Lickey ridge, as it consists in great mea- 

 sure of the same materials, but it may be distinguished by containing, in addition, 

 many fragments of slaty rocks, and by the sand in which the pebbles are imbedded 

 being freer from red argillaceous matter, and consequently of a whiter colour. 

 This gravel attains on the line of the railway a height of 544 feet above the sea 

 (not 387, as misprinted, or 587, as corrected in the Proceedings, vol. iii. p. 316). 

 I may here remark, that the gravelly soil of the Lickey Beacon, 900 feet high, 

 which has been quoted as an example of superficial gravel at a great elevation, 

 may very probably not be derived from these recent or " diluvial" deposits, but 

 from the genuine new red conglomerate, though its existence in situ cannot be de- 



* See Report of British Association, 1839, Sections, p. 71. t See sheets 30 and 31. 



X See sheet 28. 



