Читать книгу The Romance of Modern Geology. Describing in simple but exact language the making of the earth with some account of prehistoric animal life онлайн

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The wrecks dissolve above us: their dust drops down from afar—

Down to the dark, to the utter dark where the blind white sea-snakes are.

There is no sound, no echo of sound, in the deserts of the deep,

On the great grey level plains of ooze, where the shell-burred cables creep.

It is in these silent depths that for uncounted and innumerable years the crust of the earth has been forming and has been growing outwards, while it has been slowly hardening inwards above the fires of its unplumbed interior.

It has been calculated that in a square mile of the ocean down to a depth of one hundred fathoms there exist more than sixteen tons of carbonate of lime in the form of the bones or shells of living animals. A continual fine "snow-storm" of dead chalky animals is therefore falling on to the bottom. Here and there, especially among volcanic islands, portions of the sea-bed have been raised up into land and masses of modern limestone. Though these rocks are full of the same kinds of shells as are still living in the neighbouring sea, they have been cemented into hard rock. This cementing is due to the water which has penetrated and permeated the stone, dissolving chalky matter from the outside shells, and depositing it once more lower down and farther in, like a fine mortar, so as to bind the mass together.