180 r, MACKINTOSH ON THE DRIFT-DEPOSITS 



between Shrewsbury and Wellington*. From tbe neighbourhood of 

 Crewe, Cheshire (where it is extensively distributed, in many places 

 over middle sand), it attenuates in a S.8.E. direction along the line 

 of railway, and, so far as I could see, disappears at the water- 

 parting ; and on descending towards Stafford, instead of clay over 

 sand-and-gravel, sand-and-gravel over clay gradually makes its 

 appearance. About Stafford, between Stafford and Wolverhampton, 

 and along the North-western Railway for a great distance in a 

 S.S.E. direction, sand is found over clay. 



Prohahle Extension of the Upper Boulder-clay along the Lower 

 Course of the Severn Valley. 



It is not necessary to suppose that the maximum surface -level of 

 the Upper-Boulder-clay sea on the north and west side of the great 

 Wrekin and Ashley waterparting was lower than (say) 600 feet above 

 the present sea-level, because an exhaustion of supply from the 

 great northern source would of itself prevent clay from crossing 

 many of the gaps in the waterparting. It is possible it may have 

 found its way through some of them in places to which my obser- 

 vations have not extended ; and I have noticed the appearance of a 

 gradually degenerating extension of this clay from Cressage (where 

 it is tolerably represented), through the deep Ironbridge gap, nearly 

 as far south as Bewdley; and it may possibly have found its way still 

 further south. Here and there the clay covers gravel-and-sand with 

 a tolerably distinct line of separation ; but in most places it more 

 resembles a clayey wash which has come over and mixed with the 

 upper part of the gravel and sand. The appearance of a surface-clay 

 in the Severn valley, about Buildwas and Bridgenorth, was long ago 

 noticed by Mr. Maw, F.G.S., whose paper in the Quart. Journ. Geol. 

 Soc. (vol. XX.) is full of accurate information and valuable sug- 

 gestions. 



Dispersion of Angular Debris from the Malvern Hills. 



In my former paper I suggested the possibility of a supplementary 

 distribution of small northern erratic pebbles along the lower course 

 of the Severn during shallow- water conditions, a few larger stones 

 h-QNin^ previously found their way to higher levels at least as far south 

 as Sutton (west of Hampton Loade station), and probably as far south 

 as Apperley Court, south of Tewkesbury. It would appear that there 

 has been a comparatively late dispersion of Malvern syenite (so- 

 called) around the Malvern hills and between the hills and the 

 Severn. This syenite composes an angular drift which overlies all 

 the other deposits, and which extends to low as well as to high 

 levels, as if the dispersion had taken place after the present confi- 

 guration of the ground had come into existeneef. Those who think 



* The considerable expanse of clay on Haughmond Hill up to nearly 500 feet 

 above the sea is probably on the same horizon. A degenerate attenuation of it 

 may be traced as far south as Church Stretton ; but it is questionable whether 

 it be represented even by loamy gravel as far west as Llanymynech. 



t Some years ago I had opportunities of observing many sections of drifts 

 around Malvern, where now very few are exposed. 



