220 



REPORT — 1884. 





The cuttings generally are through drift, composed of varying propor- 

 tions of sand, clay, and gravel, resting on a fairly regular surface of the 

 New Red Sandstone rock of the district. Except near King's Norton, 

 this drift, so far as it has been i-xposed by these excavations, is entirely 

 free from erratic blocks, the largest stones not averaging more than 3 in. 

 or 4 in. diameter. 



At a point on the railway near the village of Stirchley, about 4?, 

 miles from Birmingham, the drift is composed of a tenacious marly clay 

 unstiiitified, and with very sparsely st'attci'ed Bunter pebbles. A few 

 erratic blocks (presently to bo catalv^gued), averaging in size about 1 ft. 

 6 in. X 1 ft. X 1 ft., were found, mostly of a felsitic rock. 



About 50 yards to tlie south of this point, the nature of the drift 

 changes to a dark red clay with angular gravel, which gravel consists 

 mostly of fragments of broken-up slate. This angular gravel overlies a 

 dark red clayish gravel made up of Bunter pebbles, but having no angular 

 fragments. 



Below these gravels is a band of pale-coloured loose sand, about 2 feet 

 thick, and much contorted. 



Below this again is a sandy gravelly clay resting immediately upon a 

 green shale or marl, the basal bed of the Keuper. All these gravels con- 

 tain erratic blocks in large numbers. 



About a quarter of a mile from this point a few ei*ratic blocks have 

 been obtained from a matrix of very sandy clay, interstratitied with beds, 

 about two or three inches thick, of a more gravelly clay, and containing 

 rounded pebbles, and angular fragments of coal shale, carboniferous grit, 

 &c., besides small blocks of the basal rock of the Keuper above mentioned. 



At this point in a dell at tiie side of the railway is a large felsitic 



boulder (No. 2 in the subjoined list), measuring G ft. ;> in. x4 ft. 9 in. 



X 3 ft. 9 in. : only about one-thii-d of it is visible above ground, the rest 



being buried in clay. The ground was dug away from it in order that a 



photograph might be taken, but was subsequently put back again 



Near the junction of the new railway with the main line to Gloucester 

 is another large boulder (No. 1 in subjoined list), measuring 9 ft. x 8 ft. 

 X 3 ft., and is at the time of writing this paper lying in its original posi- 

 tion, about 9 ft. below the surface. 



The earth being removed fi"om round it to a depth of G ft., a very good 

 photograph was obtained. 



The erratic blocks found in these gravels vary in cubic capacity from 

 1 to 21G cubic ft., and include shales, slates, ashes, felsites, pure quartz, 

 carboniferous sandstone and grit, though the majority of them are 

 felsitic, and derived from the neighbourhood of the Arenig and Berwyn 

 Hills of North Wales. 



A few of these blocks, more especially those derived from slate rockp, 

 retain ice-markings and smoothing. 



The majority of them, however, have rough surfaces with no ice- 

 markings of an/ kind. 



Subjoined is a list of the chief erratic blocks found in the above 

 Stirchley gravels, which have been examined and identi6ed by Di'. 

 Lap worth. 



1. Rough, bluish-green, folspathic ash, with crystals of felspar ; no 

 stria9, no smoothing. Size, 9 ft. x 8 ft. x 3 ft. 



2. Rough, amygdaloidal or brecciated green felstone ; no smoothing, 

 no strioe. Size, 4 ft. 9 in. x G ft. 3 in. x 3 ft. 9 in. 



