Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/308

200 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 12, The valley near Hillmorton church is very singular in its character. All round the church, and extending up and down the valley for some distance, is a peat-bed, which is exposed in some of the deep ditches. Underneath it is sand, so impregnated with water as to be called a quicksand. It appears that not long ago all this was a marsh ; for Dr. Bucknill, of Hillmorton Hall, informs me that a sum of money was left to the parish to keep up a floating cause-way over the marsh to the church, which stands on firm ground in the middle of the valley. Sand overlies the peat at the bridge over the canal near the church, just opposite the mouth of the narrow valley with the sand-pits in which the village lies. The London and North-western railway crosses a portion of the marsh ; and immense quantities of ballast were thrown in to make a firm foundation ; finally, I am informed, faggots were used as a foundation for the embankment. Similar difficulties were met with in constructing the canal. The excavations at the locks drained the sand, and the fall of the neighbouring houses seemed imminent. These houses are built in some cases on large slabs of concrete resting on the wet sand.

I caused a boring to be made here near the New Inn. It gave : — peat 3 feet, clay 1 foot, sand 25 feet ; and it was impossible to proceed further. The sand was mixed with fine clay, and contained a good deal of lime, so that when dried it soon became perfectly hard. The microscope showed grains of chalk and of rolled quartzose sand. The bottom of this boring was 280 feet above the sea.

The next boring was made in a meadow belonging to Dr. Bucknill, called the Moors. It gave 2 feet peat, 13 feet wet sand, 3 feet gravel, and then sand, more and more clayey and stiff, passing from yellowish to grey until it became too stiff for boring at 53 feet. All this sand contained fine clay and particles of chalk, effervesced slowly but continuously with acids, and was entirely unlike Lias clay. A very few small stones were met with, but not preserved.

The next boring was on the left-hand side of the road from Rugby to Clifton, on the right bank, close to the stream. It passed through 6 feet of alluvial soil and clay, then a mass of vegetable matter, being the decayed vegetation of the old river-bed, and then reached sand similar to that higher up the stream at Hillmorton. Several stones, flints, grits, and quartzite were met with in this boring. The lower part yielded a considerable quantity of chalk lumps in the clay. This boring was persevered in till 57 feet were passed through, and then rock was reached, and some fragments of limestone brought up. The bottom of this boring was 227 feet above the level of the sea.

The last boring was lower down the stream, close to the planks on the left bank of the river. It passed through fine yellow clay for 7 feet, then stones and sand for an inch or two, and then undisturbed Lias clay, totally unlike the clays previously reached. The boring was continued for 20 feet through this, and then stopped. The surface of the Lias clay here is 274 feet above the sea.

The relations of these borings will be understood by reference to