On a Late Glacial Stage in the Valley of the River Lea, Subsequent to the Epoch of River - Drift Man

Abstract

I. The Discovery of the Arctic Bed For some few years past the Great Eastern Railway Company have been obtaining remains of the Mammoth from a large ballastpit, known as the Pickett's Lock pit, at Ponder's End (Middlesex). Many of these remains, through the instrumentality of Mr. A. Atkins, of the Engineers' Department of the Company, have been carefully preserved, and are placed in the Board Room at Liverpool Street Station, the London terminus of the Great Eastern Railway. The Pickett's Lock pit at Ponder's End is an extensive one, and it is situated in the Low-Level River-Drift of the Lea Valley. The surface of the ground lies at about 43 feet above Ordnance datum, and is but slightly raised (to an amount of 2 or 3 feet) above the present alluvial flood-plane of the river. The pit exhibits a very fine section, chiefly composed of gravel and sand, showing the effects of strong current-action. There is a subordinate capping of brickearth, which does not exceed 4 feet in thickness, and is usually less. The greatest total thickness of the Drift amounts, I believe, to 22 feet; but towards the western side of the pit the underlying floor of London Clay gradually rises, and the thickness of the Drift is much less. When I first visited the pit, Mr. Guy Leonard, the engineer in charge of the works, pointed out to me a dark bed, from 1 to 2 feet thick, intercalated in the lower part of the section. Some