130 GEOLOGY OF ALDEIiXEY. 



the series. The highest beds are not reached in the existing 

 development of the quarry. The vertical extent, including 

 fault repetition, is about 800 feet. The succession of varie- 

 gated sandstones and arkose in this exposure is useful for 

 checking the horizons on the coast and elsewhere. The 

 lower grits do not occur here or in Corblets Bay, the faulting 

 obscuring them in this part of the Island. 



The Eastern Grits occupy a triangular patch extending 

 from the south of Longy Bay to L'Etac a la Quoire. With 

 the exception of one quarry on the Longy Road, it is entirely 

 a coast exposure. The cliff scenery, culminating in the 

 Hanging Rocks, is the finest in the Island. Good climbing 

 may be effected in studying this area, and all of the bays, 

 L'Etac a la Quoire, La Tchue, Les Becquets, Essex Castle 

 Bay, and Loney Bay, are somewhat accessible. The suc- 

 cession is readily followed, the N.E.-S.W. strike coinciding 

 with the lie of the Island, and the pebble beds are found at 

 either extremity. Numberless faults occur parallel with the 

 strike, and the middle and upper portions of the series are 

 not seen in such detail as in Mannez Quarry. 



Just north of L'Etac a la Quoire, on the beach and also 

 on the heights, a grey -white sandy grit, faintlv banded, fine 

 in texture, forty feet in thickness, overlies six feet of banded 

 puce-coloured grit, the latter over-lying six feet of a coarse 

 pebbly grit, purple in colour. The purple grit contains "frag- 

 ments of the diorite or tonalite on which it lies. 



At the highest point of this area, the Hanging Rocks, 

 are the variegated pink and green arkose bands. Lower, 

 towards Essex Castle, they are finer, with fewer green bands. 

 There is faulting; at the Castle rocks, the higher beds being 

 repeated to northward. A grey-white grit is reached, over- 

 lying alterations of pink grits and yellow sandstones. Fur- 

 ther north, until Longy Bay is reached, are the alternating 

 pink and green grits. The cliff sections are 200 feet in 

 height and the average dip is to S.E. at 20°. 



Interesting features are seen in the Longy Quarry, 250 

 yards south-west of the Nunnery. In the lowest horizon is 

 a conglomerate. The largest pebbles are three inches in 

 diameter. There are fine aplite, rhyolite, purple quartzite, 

 and quartz pebbles. Some of these are angular. The 

 smaller fragments are rounded and broken felspars and 

 quartz from a decayed granite. The tint is pinkish. The 

 higher beds, usually pink, are arkose. No other exposures 

 of the grits are seen north or west of this quarry. Further 

 working might disclose the igneous rock, probablv diorite, on 

 which the grits lie, but the quarry appears to be abandoned. 

 The south-eastern area is an isolated patch, opposite Coque 



