Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/107

 Rh which this formation lies in France and in England, some persons have been led to consider it as one and the same, and consequently to conclude that the British channel, which separates these parts which are now opposed to each other, has been formed after the chalk had been deposited. I shall not however enter upon the discussion of the merits of that opinion, which if examined in detail, would offer several difficulties, as I do not think that it is necessary to adopt it, in order to account for the facts which present themselves.

One of the distinctive characters of this formation, is the disposition of the flint in beds or layers, nearly parallel to each other, though at unequal distances, so that whatever be the shape of the country at the surface, whether it be hilly or flat, the beds of flint preserve a nearly uniform parallelism with the surface of the ground; this is tolerably well seen in Dorsetshire, a county, the outline of which is very undulated. This kind of hilly ground is known in England by the name of downs. In Hampshire, in the western part of it especially, there are elevated plains, and occasional depressions, but these last are not sufficiently deep nor do they succeed to the former so rapidly as to entitle that district of country to the name of downs.

Flints near their original situation do not always appear in the form of pebbles, but often in masses of a more or less considerable size, and of a shape sometimes flatted and irregular. It is chiefly in alluvial ground formed of a slightly aggregated gravel, that flints are found in the state of pebbles, of different sizes, according to the friction they have undergone, and consequently, according to the distance from which they have been brought: hence, the individual pebbles of which gravel consists, become in general smaller and smaller as they approach the sea.