178 The Geology of the Berks 8f Hants Extension, 



ordinary chalk, and do not suffer from the action of frost. 



At about 4 feet below the Chalk-rock there is here a succession 

 of irregularly shaped cavities filled with a brown sand, probably of 

 Tertiary age, which has found its way beneath the Chalk-rock from 

 its outcrop on the surface, and not through it in sand pipes. The 

 Chalk- rock dips at an angle of 27° nearly true north, and higher up| 

 at the road from Wootton Rivers to Forest Gate, the dip is as] 

 much as 45° in the same direction. The Chalk here appears to have 

 suffered considerable tilting up and denudation before the deposi- 

 tion of the Tertiary beds ; otherwise sand of the latter age could 

 hardly have penetrated into the lower-chalk. The present surface 

 of the hill is free from any drift, only a few inches of soil 

 covering the chalk. The thickness of the Lower-chalk appears to be 

 about 360 feet, but the data are insufficient for accurate measure- 

 ment. 



Fig. 5 repre- 

 .. flints sen ts a disturb- 

 ance in theChalk- 

 •fi ints with -flints, visi- 

 ble near the end of 

 the cutting, and 

 on each side of 

 it. It does not 



Fig. 5. Section near road from Wootton Rivers to Forest-gate. aDpear to be a 



fault, as the lines of flint resume their course after passing through 

 it. The sides are marked by sharp lines, within which the chalk 

 looses its regular stratification and becomes confused. A band of 

 flints dips down in a V shape, in which the flints are not so continuous 

 as in the undisturbed portions. Above the V the chalk is inter- 

 mingled with brown clay, and lies in curves. 



Inoceramus Brogniartii, Spondylus spinosus, Terebratula carnea, 

 Micraster cor- anguinum occurred in the Upper-chalk here. 



On reaching the high table land, we come to a succession of cut- 

 tings very similar in character. 



A drift of re-arranged Tertiary beds lies on the chalk, the upper 

 surface of which is exceedingly irregular. This drift is principally 



