140 



PROP. T. T. GROOM ON THE GEOLOGICAL [May 1 899, 



the dip appears to be east-south-easterly at from 60° to 72°, while 

 in the bed of the stream it is north-westerly at 25°. The strip 

 is accordingly composed of beds which, in the south striking appa- 

 rently parallel to the line of outcrop, in the north strike on the 

 one hand against the gneissic series, and on the other against the 

 May Hill Sandstone ; it must, therefore, be bounded by two 

 fipproximately parallel faults. 



Pig. 8. — Section across the northern slojje of Midsummer Hill. 



i^i^= Faults. 



e=Keuper Marls. 



d—Beds of May Hill Sandstone 

 with StricMandinia. 



[Scale : 3 inches = 1 mile.] 



c:= Lower beds of May Hill Sand- 

 stone, with Ctenodonta, Lin- 

 gula, etc. 



6=^ Holly bush Quartzite and Con- 

 glomerate. 



(Z= Archaean. 



Towards the south the conglomerate cannot be traced as far as 

 the northern limit of the Hollybush Sandstone ; it is probably cut 

 out by the meeting of the two faults which bound it. Moreover, 

 a continuation of one of these faults probably truncates the Holly- 

 bush Sandstone and the Black Shale which occur on the western side 

 of Midsummer Hill. To the north, both the gneissic series and the 

 conglomerate are cut off by a transverse fault running east and west 

 down the Gullet Pass. 



Pig. 

 W. 



-Section of dyke on the northern side of Hollyhush Pass. 



Basalt Dyke 



[Approximate 



Hollybush Sandstone 

 : 1 inch = 11 yards.] 



The extent and disposition of the Hollybush Sandstone on the 

 western slope of the hill are difficult to make out, as exposures are 

 few, but careful examination makes it evident that the sandstone 

 forms a somewhat narrow strip, bounded on the west by a fault 

 which is approximately parallel to that on the eastern side of the 

 strip. The position and direction of the fault can be determined 

 by the junction along the middle of its length with the Black Shales 

 on the west, and by the abrupt change in the strike and dip of the 

 sandstone along the road from Hollybush to Upper House Farm. 

 The fault is marked here by a slight depression running down a 



