Notes on the gravels of the Upper Thames Flood Plain between Lechlade and Dorchester

Abstract

The paper deals with gravels which occur near the present level of the Upper Thames, and below it in terms of selected illustrative examples, mainly of recent discovery. It covers about fifty miles of the river, from the headwaters around Cricklade, where the origin of some pebbles is discussed, to Goring gap, where it is shown that a knick-point in the present river accentuates the relative height of old marginal gravels which lie upstream. The deposits of the Summertown-Radley Terrace around Oxford consist of a lower part, with a fauna characterised by woolly rhinoceros and associated fauna, and an unconformable upper part yielding hippopotamus and associated mammalian and molluscan faunas: Acheulian implements occur. The Flood Plain gravels are now known to contain remains of Siberian mammoth and reindeer, with recently discovered contemporary molluscan fauna and flora, which are described in an Appendix. No human industry has yet been attributed to the Flood Plain gravels. Means of distinguishing between the older Summertown-Radley gravels and the younger Flood Plain deposits, in the field, are explained, and it is shown that low-lying extensions and gravel-filled channels of the former occur locally beneath the latter (as at Lechlade and Dorchester).