328 Geological Society. 



January Gib, 1904.— Sir Archibald Geikie, D.C.L., D.Sc, Sec.R.S., 

 Vice-President, in the Chair. 



Tbe following communication was read : — 



' Implementiferous Sections at Wolvercote (Oxfordshire).' By- 

 Alexander Montgomerie Bell, Esq., M.A.,F.G.S. 



This section shows the following beds : — (1) Oxford Clay ; (2) old 

 surface, in which are pits or troughs chiefly filled with gravel and 

 enveloped in weathered clay; (3) a large river-bed, containing gravel 

 at the base, and layers of clay above ; (4) Neolithic surface-layer, 

 2 feet thick. The gravel of the river-bed contains quartzite-pebbles, 

 some of exceptional size, and is covered by a thin lenticular layer of 

 peat and sand, yielding thirty flowering-plants and many mosses; tbe 

 clays over this have probably been formed in a lake, possibly due to 

 a beaver-dam. In the gravel-bed are found implements formed of 

 flint quarried from tbe Chalk, or of quartzite from pebbles of the 

 Northern Drift, all remarkable for their size, beauty, and freshness, 

 together with tbe remains of large mammals, including the mammoth. 

 The old surface, from which the river-bed has been eroded, has 

 also yielded implements associated with quartzites, quartz-pebbles, 

 and lydianstone, gravel from the Thames Valley, limestone-pebbles, 

 Oolitic fossils, and sand. This deposit is regarded as remanie 

 from the Northern Drift, probably laid down under the action 

 of ice, as shown by the flask-like shape of the pits, the vertical 

 position of some of the pebbles, and the jamming-in of masses 

 of sand, probably in a frozen condition. Further, the Oxford 

 Clay beneath the surface is weathered and shaken to a depth 

 of 10 or 12 feet, except where cut off by the descending depth of 

 the river-bed. Tbe implements are small, ordinary in shape, and 

 made of flint, not quarried, but mostly taken from the Drift, and . 

 they are much weathered, stained, and patinated. Tbe occurrence 

 of an older set of implements, differing so markedly from those of 

 the river-drift, leads the Author to explain the peculiar imple- 

 mentiferous drift of Iffley as containing implements of two kinds 

 and two dates. Those that are unweathered are contemporaneous 

 with the deposit, and like those of the Wolvercote river-bed ; while 

 those that are stained with ochre, or deeply patinated, have been 

 derived, like the Oolitic fossils, Tertiary conglomerate, quartzites, 

 and volcanic rocks, from an older deposit, The Author believes 

 that the frequent occurrence of weathered and unweathered im- 

 plements in a single deposit may be explained generally in this 

 way ; and he further infers that the time between the Drift and 

 the Kiver-bed was prolonged, and that the interval may have been 

 as long as that which separates the epoch of the River-bed from the 

 present day, his evidence being simply the patination of the flints. 

 In conclusion the Author suggests that there are three classes of 

 implement-bearing drifts, the ice-drifts being the earliest and the 

 river-drifts the latest, while the wash-drifts may belong to more 

 than one stage. 



