Page:Transactions of the Geological Society, 1st series, vol. 3.djvu/402

 greater flux at the time of high water, and particularly at spring tides; showing that the water in the chalk communicates with the sea, a circumstance which would lead to a supposition that the sea rests immediately on the chalk at a certain depth: if so, we might possibly expect that the agitation of the water would frequently throw up chalk on the coast, which I have never yet observed.

The chalk consists of two colours, red and white, each lying in regular strata, the red being generally undermost: in the white, seams of flint are frequently met with from two to six inches thick.

The stratum, No. 3, immediately below the chalk, is a coarse brown pebbly sand without organic remains, consisting of quartz and oxyd of iron. This bed is, I apprehend, of irregular thickness; I suppose it may vary from six to ten yards, but its appearance at its basseting is very uncertain; for, being of a very loose texture and the chalk which reposes upon it being of a more compact nature, it is evident that when these parts were exposed to the action of water, the sand being less capable of resisting the washing of that element than the chalk, this latter would be left in many instances forming projecting cliffs; which time, and the well known action of the atmosphere, would crumble down over the sand, and form those declivities which now in such variety are exhibited to our view.

The next bed, No. 4, contains in nearly equal proportions oolite limestone and calcareous clay of a lightish grey color. In certain parts of this bed the clay divides the seams of stone into regular strata; in others the stone is found to occur in the clay in large detached pieces. This bed never extends to any great distance beyond the chalk, forming in general a sort of step at the foot of its basset. Lumps of pyrites are frequently met with in the limestone. The thickness of the entire bed of stone and clay may be