270 QUARTERLY JOURNAL. 



Mr. Lyell to floating ice, within which stones were fast frozen, that 

 acted like gravers, and cut the rock as the iceberg floated along. 

 Thus the grooving of the rocks, the transported beds of boulders, 

 gravel and sand, and the fine clay connected therewith, are all the 

 product of transport. This we infer especially from a remark on page 

 128 : " Nothing, however, is clearer, than that here, as well as in 

 the valley of the St. Lawrence between Kingston and Quebec, the 

 marine shells of recent species are referable to the same geological 

 period as that to which the boulders belong." This period embraces 

 all, beginning with that power which scored the rocks, and ending 

 with the deposition of sand forming the upper part where the 

 deposits have not been disturbed. 



We, however, regard the matter thus : There was a force which 

 moved the rocks, coarse and fine, and grooved the floor upon which'j 

 they moved from north to south. This force we consider to have 

 been sui generis ; that is, distinct from that which carried boulders 

 subsequently, and which contained the then living animals that wei 

 now find in the clays and sands of the vallies named above. There 

 is enough in this first movement, to entitle it to the character of a 

 period, and to stand by itself. To this succeded a period of quiet, 

 during which the clays and sands were deposited, as in most casesi 

 where the structure and character of the beds is the same ; for these 

 are perfectly fine sediments, consisting of extremely fine layers 

 of clay, alternatthg with extremely fine sand, the entire thickness ol 

 the whole amounting to over one hundred feet. This we say v^as 

 the product of a period of perfect quiet, during which marine ani- 

 mals lived ; and so perfectly quiet was it, that the thin fragile shel 

 of the Terehratula psittacea preserves both valves in contact, anc 

 still attached by the hinge : indeed, perfect tubes in the sand, linec 

 with calcareous matter, and which are coeval with the time of dc" 

 posit, remain to this day. We separate this quiet period from the 

 preceding, which was one of turmoil and violence ; and, we think, 

 justly, because the two are so dissimilar in character. At some 

 places, as at Port Kent and Chimney point, the fine sediment of cla) 

 rests upon the grooved surface of rock : at other places, there are 

 beds of stones, boulders, gravel, sand, etc. upon the grooved surface 

 and these are the masses that have been borne along with, anc 

 formed a part of, the drift current. But upon these very drift bedi 

 reposes a fine sediment of clay and sand alternating, in which it is 



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