Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/327



Section in gravel-pit, Kempsey.

Surface of ground. ft. in.

(1) Light-red loam, with a few pebbles 2 0

(2) Dark-red loam and pebbles 2 0

(3) Dark-red sand 0 3

(4) Fine light-red sand and gravel 1 10

(5) Light-red sand 0 3

(6) Fine light-red sand (obliquely laminated) and gravel 1 0

(7) Dark-red sand 0 3

(8) Fine light-red sand (laminated obliquely), gravel, and large pebbles 1 0

(9) Red sand 0 3

(10) Fine light-red gravel and sand (obliquely laminated) 1 6

(11) Red sand, containing lumps of red marl 0 9

(12) Fine gravel and sand, containing a large proportion of greenish-coloured pebbles, with many large pebbles intermixed 2 0

(13) Clean red sand and shingly gravel, containing pebbles about the size of a bean 1 6

Uneven surface of basement rock of red marl.

14 7

Section in a gravel-pit near Haivforcl Bridge.

A compact bed of gravel, made up of large and small pebbles of the ordinary type ; and dark-red loamy sand. In the upper part of the bed were carbonaceous seams, about 2 inches thick, dipping at a slight angle towards the river 15 0

New red marl.

Composition of the gravel. — The pebbles which form the chief constituents of the gravels of the Severn valley between Bewdley and Tewkesbury are composed of a greenish slaty-coloured rock, containing veins of white quartz, the presence of which distinguishes them in great measure from the " general quartzose drift " of the Avon district, of white quartz, felstone, and a few flints. The occurrence of boulders and pebbles of grey pophyritic granite is most frequent in the upper portions of the valley.

Modern alluvium. — This deposit appears to be the only one of proved freshwater origin which has hitherto been found in the Severn valley between Shrewsbury and Tewkesbury. It consists of a bed of silt, to all appearance like that of the Avon valley. Mr. Maw has kindly supplied me with the following details of a boring made near the edge of the river's bank, close by Buildwas railway bridge.

ft. in.

(1) Vegetable soil 1

(2) Stiff loam (Loess) 8 6

(3) Running sand 2

(4) Gravel similar to that at Buildwas station. Freshwater mussels 4 6

16

Basement rock Wenlock shale, at a depth of 7 ft. below the river's surface.