G. H. Ki,iahan—A Faulted Slate. 123 



from the En the new line in its south-easterly course has a deep 

 cutting in Penwood, through Tot Hill. Here the Bagshot Sands, 

 upwards of 30 feet thick, with a dip of about 3° to the southward, 

 rest on clay,^ and are covered with 12 feet of coarse, ochreous, and 

 loamy gravel. The sands at one part of the cutting were seen (in 

 August, 1882) to consist of — at top — 



Tellowisli, brown, and grey laminated sands, 16 feet. 



Brownish -blue shale ^bluish inside, brown outside), 4 feet. 



Blue-black shale, 6 feet. 



"White clay, 2 feet 6 inches. 



White sand — not cut through when the observation was made. 



To return to the Oyster-bed, I was informed by Mr. Drj^sdale that 

 he had met with these Oyster shells in the railway-cutting by 

 Hockley PTole, 2 miles east of Highclere and 3 miles west of Kings- 

 clere. The Woolwich-and-Reading beds have their outcrop along 

 this line, forming part of the southern limit of the so-called " London 

 Basin." Prof Prestwich's sections of some localities hereabouts are 

 reproduced in the " Memoirs Geol. Survey," vol, viii. pp. 102, 103. 



Recurring to the first pai't of these Notes, we may say that, if ilie 

 dip of the beds he about 3° south (as it is apparently at Enborne 

 Lodge Wood and Tot Hill), the thickness of the Lower Eocene strata 

 between the well and the London Clay near Cop Hall (N. and S. 

 distance =:;| mile) will be about 60 feet, approximately coinciding 

 with the known thickness of the Woolwich-and-Reading series on 

 the other side of Newbur3^ 



YI. — A Faulted Slate. 

 By G. H. KiNAHAN, M.E.I. A. 



IN the interesting description of a faulted slate (Geol. Mag. Jan. 

 1884, p. 1) by Mr. J. J. Harris Teall, the writer appears to 

 consider that all faults are due to up-and-down movements ; wliile 

 he seems to ignore the horizontal or transverse heaves, that is, move- 

 ment of the strata from side to side. 



In the newer strata, which are not much moved from their original 

 horizontal position, such as those of the South Staffordshire Coal- 

 field, or of the Weald, the majority of the dislocations appear to be 

 due to upward or downward movement ; but this is not the case 

 among the older contorted and crumpled rocks, where in general the 

 horizontal heaves usually equal, if they do not exceed, the up-and- 

 down faults in number. Consequently'^, while reverse faults are rai'S 

 in nearly horizontal rocks,''^ they are not uncommon among the 

 contorted and crumpled strata. 



A good example of one of these reverse faults occurs in the Crone- 

 bane Mineral Channel, co. Wicklow. To the west there is a left- 

 hand heave that jumps the lode northward, but further east there 



' This now forms the floor of the cutting and gives rise to slips. It is probably 

 the London Clay. 



■•^ Those that I have been able to examine appear to be more the result of a 

 horizontal heave, thaa of a thrust upward. 



