904 PROFESSOR J. PRESTWICH ON THE EVIDENCES OF A SUBMERGENCE 
Introductory Remarks. 
In a paper read before tbe Geological Society* early this year, I gave the evidence— 
the result of personal observation—which led me to conclude that the South of 
England had been submerged to the depth of not less than about 1000 feet between 
the Glacial (or Post-glacial) and the recent or Neolithic periods. That evidence was 
based upon the characters, jDhysical and palaeontological, of a peculiar superficial drift, 
for which I proposed the term of “ Rubble-drift,” to distinguish it from the valley, 
marine, and glacial drifts of the same districts.t Under this term I include various 
detrital deposits to which different designations have been attached. Amongst the 
more important of these are the drift called “head” over the Raised Beaches of the 
Channel and the Ossiferous Fissures of South Devon. 
Various explanations have been suggested to account for the “head,” such as, 1st, 
an excessive rainfall, accompanied by great cold; 2nd, the sliding of masses of snow 
and ice over slopes ; 3rd, waves of translation ; 4th, torrential fluviatile action during 
a period of great cold. I have stated in the paper referred to the objections to these 
several explanations.^ Some of them, no doubt, would sufiice to produce a portion of 
the observed effects, but they fail to embrace the whole, and they all involve conse¬ 
quences which are incompatible with the general facts. They all, also, with one 
exception, depend on subaerial agencies, to which there is the general objection that 
these ao;encies involve a certain amount of friction and weatherino- which are con- 
spicuously wanting—or, if present, it is in a very slight degree—in the deposits 
under review. There is the further objection that some of the phenomena indicate 
the exercise of a propelling force for which the suggested causes are manifestly 
inadequate. There are other points, apparently inconsistent with such agencies, con¬ 
nected more especially with the Ossiferous fissures and the Loess of the continental 
area, which will be considered more fully in the following pages. 
In the jDresent paper my object will be to show that the phenomena on which I 
relied as proofs of submergence in England, extend likewise over large continental areas. 
Owing to the extent of the subject, it will be necessary to confine the inquiry to the 
more prominent and typical cases. Nor will it be necessary to give full geological 
details, as they are to be found in the works of the several geologists referred to. I 
* ‘ Qxiai't. Journ. Geol, Soc.,’ vol. 48, p. 263, 1892. I have there entered into more details, and specified 
the objections to previous explanations, "which it is therefore unnecessary to repeat here. 
t Both Sir R. Murchison (‘ Quart. Jornm. Geol. Soc.,’ vol. 7, p. 349), and Professor J. Geikie 
(‘Prehistoric Europe,’p. 140), have contended that certain detrital deposits, spread widely over the 
South of England, could not be referred to ordinary marine or fluviatile agencies. The former attri¬ 
bute them to a wave of translation : the latter (which I unknowingly overlooked in the above-named 
paper) to the agency of frozen snow-drifts during the Glacial period. 
+ Ibid., pp. 326-328. 
