Geological Society of London. 189 



caves is the last fauna of the Glacial or post-Glacial period, and the 

 ' head ' or Eubble-drift marks the closing chapter of Glacial times. 



Evidence is given for considering that the ' Eubble-drift ' has 

 a wide inland range, and that to it are to be referred the ' Head ' of 

 De la Beche, the Subaerial Detritus of Godwin- Austen, the Angular 

 flint drift of Murchison, and in part the ' trail ' of Fisher and the 

 ' warp ' of Trimmer, as well as other deposits described by the author. 

 The accumulation is widespread over the South of England, and 

 occurs in the Thames Valley, on the Cotteswold Hills, and on the 

 flanks of the Malverns. The stream-tin detritus of Cornwall and 

 the ossiferous breccia filling fissures (which must be distinguished 

 from the ossiferous deposits of the true caves) are held to be repre- 

 sentatives of the ' Rubble-drift,' which is of a variable character. 



The author discusses the views of previous writers on the origin 

 of the accumulations which he classes together as ' Rubble-drift,' 

 and points out objections to the various views. He considers that 

 they were formed on upheaval after a period of submergence which, 

 took place slowly and tolerably uniformly : and that the absence 

 of marine remains and sedimentation shows the submergence to 

 have been short. This submergence cannot have been less than 

 1000 feet below present sea-level, and was shortly brought to a 

 termination by a series of intermittent uplifts, of which the ' head ' 

 affords a measure, sufficiently rapid to produce currents radiating 

 from the higher parts of the country, causing the spread of the 

 surface-detritus from various local centres of higher ground. The 

 remains of the land animals killed during the submergence were 

 swept with this debris into the hollows and fissures on the surface, 

 and finally over the old clifl"s to the sea- and valley-levels. Simul- 

 taneously with this elevation occurred a marked change of climate, 

 and the temperature approached that of the present day. The 

 formation of the ' head ' was followed in immediate succession by 

 the accumulation of recent alluvial deposits; so that the Glacial 

 times came, geologicall}' speaking, to within a measurable distance 

 of our own times, the transition being short and almost abrupt. 



In this paper only the area in which the evidence is most com- 

 plete is described. The author has, however, corroborative evidence 

 of submergence on the other side of the Channel. 



2. " The Pleistocene Deposits of the Sussex Coast, and their 

 Equivalents in other Districts." By Clement Reid, Esq., F.L.S., 

 F.G.S. (Communicated by permission of the Director-General of 

 the Geological Survey'.) 



The gales of last autumn and early winter exposed sections such 

 as had not before been visible in the Selsey Peninsula. Numerous 

 large erratic blocks were discovered, sunk in pits in the Bracklesham 

 Beds. These erratics included characteristic rocks from the Isle of 

 Wight. The gravel with erratics is older, not newer as is commonly 

 stated, than the Selsey 'mud-deposit' with southern mollusca. 

 Numerous re-deposited erratics are found in the mud-deposit, which 

 is divisible into two stages, a lower, purely mai'ine, and an upper, 

 or Scrohicularia-ViiVidi, with acorns and estuarine shells. 



