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VII. — Observations on the Geological Structure of the Neighbourhood 



of Reading. 



By J. ROFE, Jun., Esq. 

 Communicated by Robert Hunter, Esq., F.G.S. 



[Read Feb. 26, 1834.] 



1 HAVE the honour of presenting- to the Geological Society a few specimens 

 illustrative of the geology of the immediate neighbourhood of Reading; and 

 I may, perhaps, be permitted to accompany them with a short account of the 

 beds in which they were found. 



The substratum of the neighbourhood of Reading is the upper chalk, 

 abounding in fossils and flints, many of the latter containing sponges or 

 other organic remains, and very many having cavities lined with crystals of 

 quartz of various colours, or with mammillated chalcedony. The chalk on 

 the north-west side of the town, rises abruptly a short distance from the 

 Thames, forming a range of hills ; but on the north-east more gradually, 

 and the hills are farther from the river. The high land which, in Reading, 

 separates the Thames and Kennet, rises suddenly from the Holy-brook (a 

 tributary of the Kennet), but falls gradually towards the Thames from the 

 Basingstoke Road to Caversham Warren. The highest part of this ridge is 

 covered by gravel, under which are numerous beds of sand and clay, be- 

 longing to the plastic clay formation. In the Thames valley the chalk is 

 principally covered with the gravel over which that river flows. To the 

 south of the town is also a range of high land, bounding the Thames and 

 Kennet valleys ; and, like the ridge between the two rivers, belongs to the 

 plastic clay; while on the western side, in the Kennet valley, several brick- 

 fields are novv worked through all the strata of that formation to the chalk; 

 and it was in these beds that most of the specimens were found. 



In the Katesgrove field, wrought for considerably more than a centuiy, the 

 clay for bricks and tiles is procured from the side of the hill above the general 

 level of the field; but the chalk, used for lime, is obtained from pits sunk be- 

 neath it, though never to a depth exceeding fifteen or sixteen feet, as the 

 water prevents deeper excavations. The upper part of the chalk, for about a 

 foot, is in a very singular state. It can scarcely be called chalk-rubble, but 



