Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/258

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Mr. Webster on the Strata lying over the Chalk.

extraordinary phenomena. From the correspondence in the situation of the chalk and the accompanying strata in the Isle of Wight and Dorsetshire, it should seem, that the range of chalk hills in each of these places was at first united; and thus a marine gulph was formed, open to the east, in which a part of the depositions at that time going on in the ocean subsided.

The observations of several geologists have shewn the natural tendency which the sea has to fill up æstuaries, and to throw up bars across their mouths by the accumulation of pebbles and sand. Many remarkable instances of this process have been observed on the shores of the Baltic, and even in this country. It appears also that such gulphs and bays are frequently converted into freshwater lakes, of which Loo Poole in Cornwall is an excellent example.

As it is most philosophical to seek for the solution of natural phenomena from known causes, might we not suppose that a similar circumstance has converted the gulph we have contemplated (now partly occupied by the Solent) into a lake of fresh water? If the size of the bar necessary for this purpose should appear extraordinary, we have only to recollect the Chesil bank, which now joins the Isle of Portland to the main land; and many others of the same description.

With this subject in my mind, while examining the cliff at Brighton, which has been already described, I could not resist the idea that it might possibly be the remains of this ancient inclosure of the lake. That it exhibits the vestiges of a vast and ancient accumulation well fitted for this purpose, there can be little doubt; and it is evident, that it has extended in the necessary direction, it being now a vertical section of what must have run out far into the sea.

Whether such a supposition as this can afford a solution of the