. Edinburgh New Philosophical Journal . 3. Sand. 2. Brick-clay. â' â- a- 1. Shell-clay. No. II. Uhl l- i ' >;m;i i;ii 4 1 i!'! >â¢â ' - -'!. i' i \\ . .mm imm i ⢠i; |li â¢,. f, 4NM'i i i1 !'i H'l'r niii-ii.'i'! 2. Marl and sandy clay. 1. Boulder-clay &> No. 1 stones in shel- j tered corner. I Granite. lin Fig. 2. or sandy clay, on which large boulders rest loosely. Through these a valley has been cut, where, however, the section presented in its banks is as often obscured by alluvium. A diminution of the glacial cold, and along with this a great thawing of the inland ice, seems
. Edinburgh New Philosophical Journal . 3. Sand. 2. Brick-clay. â' â- a- 1. Shell-clay. No. II. Uhl l- i ' >;m;i i;ii 4 1 i!'! >â¢â ' - -'!. i' i \\ . .mm imm i ⢠i; |li â¢,. f, 4NM'i i i1 !'i H'l'r niii-ii.'i'! 2. Marl and sandy clay. 1. Boulder-clay &> No. 1 stones in shel- j tered corner. I Granite. lin Fig. 2. or sandy clay, on which large boulders rest loosely. Through these a valley has been cut, where, however, the section presented in its banks is as often obscured by alluvium. A diminution of the glacial cold, and along with this a great thawing of the inland ice, seems to have occurred be- tween the deposition of the marl with its associated shell- beds and the later shell-clay, for the more markedly arctic character of the Fauna is wanting in the latter clay. Hence the division of the beds into the glacial and the post-glacial groups. This shell-clay was a regular marine formation, deposited in a perfectly orderly and quiet state of things ; but after its formation there must have followed a time of floods, during which the many dams, forming basins and lakes in the valleys, were cut through, and the clay, the sand, the period which we possess. They were formed at the same time that the rock surfaces in the lower districts were striated under the general covering of ice. The greatest mass of the boulder-clay, however, formed during that period, seems to have been either thrust into the sea aud left at depths still below our reach, or so mixed up with the boulder-clay of a later period as to be undistinguishable from it. That our existing boulder-clays generally belong to a later period is obvious, since they are contemporary with the marls, which are a sea deposit, formed on the submerged land, which had previously been furrowed and scratched by the old ice-covering grinding over its surface, and leaving its detritus only in such places as were protected from the motion of the ice.â[Translator.']
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Keywords: ., bookcentury1800, bookcollectionbiod, bookdecade1860, bookyear1863
