Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/159

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
TYLOR—QUATERNARY GRAVELS.
65


of Urus were also met with in the Wortley Beck Fields closely adjoining.

Section at Holbeck.

  1. Greyish sandstone
    ................................................................................................................................................................................................................................................................................................................................................................................................
    2 feet.
  1. Yellow sand
    ................................................................................................................................................................................................................................................................................................................................................................................................
    2 feet.
  1. White sand with well rolled boulders of grit and sandstone, with an occasional fragment of limestone and chert
    ................................................................................................................................................................................................................................................................................................................................................................................................
    thickness unknown.

Mr. Filiter, the engineer of the Leeds Waterworks, informed me that the exact position where the remains were found was 53° 47′ 42″ N., 1° 34′ 10″ W.

It is uncertain whether the Aire-valley gravel represents exactly the beginning of the series of the Kirkdale-cave deposits; but the discovery of the Hippopotamus 10 feet below the surface of the gravel, and only 15 feet above the present level of the Aire, clearly proves that the great mass of the Bingley accumulations was anterior to the time at which the Leeds Hippopotamus lived. If the upper series of these Bingley gravels represented in time the last deposit of 10 feet at Leeds, they would be of the same date as the Hippopotamus, and all the lower part of the gravel at Bingley below the 10-feet level would be older than the Hippopotamus.

In fig. 2, plan of the course of the river Aire between Bingley and Shipley, a curve not very remote from the horseshoe-form is seen.

The section of the river-banks at many points near this curve (see Pl. IV. figs. 4 & 5) present steep escarpments to the river, and thus preclude any supposition of glacial or marine action, as neither sea nor glacier could arrange heaps of gravel with a regular slope facing a river following its course in a horseshoe curve.

When we find a set of gravels in the valleys of other rivers deposited in slopes and levels in a similar manner, and bearing close comparison in contour, condition, mineral contents, dimensions, and position with the mammaliferous gravel of the Aire, it may be safely inferred that we are examining valley-gravels of the same date as that of the Aire, although Hippopotamus and Elephant may not be found in every river-deposit.

The discovery of Hippopotamus in such a nearly perfect and unrolled condition in the superficial deposit of the river Aire, at Leeds, was a most fortunate thing for geologists who discuss the later Quaternary deposits, as it shows that the range of the extinct Mammalia extended to a time since which there have been no changes of importance in the level, nor disturbance, of the superficial deposits in Yorkshire.

At Cottingley Beck, near C, fig. 2, there is a natural section of gravel resting on shale and clay, and containing a block of sandstone moved from a distance. It is 12 feet long, and of very great weight, and only 6 feet from the surface. This could only have been transported down the small valley occupied by Cottingley Beck by a very heavy flood, and is an indication of the amount of rain which must have fallen at the date of the accumulation of the Aire-valley gravels.

Similar animal remains to those at Leeds have been found