SUPERFICIAL DEPOSITS. 219 



nately yellow and brown. On one side of the road, near a 

 large diorite boulder, besides the fine lamination, the clay 

 also shows two beds of coarse brown loam running through it. 

 These beds are about five inches thick, and the material is 

 evidently disintegrated diorite, derived from the rock on which 

 the adjoining beach rests, and which also probably underlies 

 the clay. 



The yellow clay contains nearly everywhere angular 

 fragments of subjacent or neighbouring rocks, the largest and 

 most angular being yielded by the hardest kinds. They vary 

 in size from minute pieces up to blocks of one or two feet in 

 their greatest length, and here and there massive boulders 

 occur. The stones are found mostly in the lower part of the 

 clay, sometimes sparsely scattered through it, and sometimes 

 closely grouped together, or forming a mass at its base. In 

 some places they are spread out in the form of a layer or bed, 

 which is seen perhaps running through the middle of a section. 

 These fragments mostly lie with their long axis more or less 

 horizontal, but they are occasionally found tilted up at a high 

 angle. 



Some large blocks have travelled distances — not very 

 great perhaps — but still enough to show that a powerful 

 transporting agent was at work. The one over the St. 

 Clement's beach, already alluded to, is an example. Mr. Gr. 

 A. Picquet has drawn my attention to an interesting block at 

 Surville, exposed in a roadside section. Here there is a bed 

 of yellow clay, lying on shale with a rubble of small fragments 

 of the rock in its lower part. In this clay, with its lower 

 portion sunk into the rubble, is an angular block of banded 

 rhyolite, whose projecting sides measure 3ft. 2in., 2ft. 3in. and 

 lft. 9in. respectively. About 37 feet distant in the same 

 section there is another smaller piece of rhyolite, and there 

 are also numerous still smaller, often minute fragments, of the 

 same rock scattered about in the clay. There is evidence of 

 the presence of rhyolite within about a quarter of a mile of 

 this spot, on a higher level, at the top of a gentle slope. I 

 have only observed the banded variety there, however, in some 

 angular fragments in the clay, where the subjacent rock could 

 not be seen, and whether they were portions of it I could not 

 determine. 



Smooth, well-rounded pebbles have been found in the clay 

 in Jersey as well as in Guernsey. For example, at a brick 

 work at Mont a l'Abbe, on the high plateau ground, not far 

 from the site of the block just described, at a height of at least 

 200 feet above spring tide high water mark, and some two 



