552 TRANSACTIONS OF SECTION C. 



for the laiul-ice hypothesis and for the unity of the glaciation has been adtnirably 

 summarised by Professor P. F. Kendall.' 



The systematic researches of the late J. G. Goodchild in J'^denside,- and of 

 Mr. R. H. Tiddeman in North Lancashire and Yorkshire,^ failed to bring to light 

 any evidence for this great ' Helvetian ' break in the glaciation ; nor have the 

 later investigations farther southvrard, among which we may mention those of 

 Professor T. J, Jehu in Pembroke.shire,* and of the Geological Survey in South 

 "Wales, shown any other result. 



In support of the hypothetical Helvetian land surface in the north-western 

 region, Professor Geikie lays stress upon the discovery of a muddy deposit con- 

 taining undetermined vegetable remains and diatoms in the boulder-clay near 

 Ulverston, in North Lancashire. This material, penetrated in borings for iron 

 ore, was first described by Mr. J. Bolton,'' over forty years ago, as occurring 

 beneath the ' pinel ' (boulder-clay) and just above the Carboniferous Limestone; 

 Miss E. Hodgson '^ shortly afterwards gave reasons for believing that the ' muck' 

 had been introduced into the cavernous top of the limestone by recent streams 

 which drain underground ; and eighteen years later Mr. J. 1). Kendall ' recorded 

 further borings, which seem to show that the material sometimes occurs a few 

 feet above the base of the boulder-clay ; but his suggestion that the outcrop of the 

 bed in question may be represented by the submerged forests occurring above the 

 boulder-clay on the foreshore at Walney, Dring, and St. Bees indicates a mis- 

 apprehension of the evidence. Professor Geikie infers that the great mass of 

 boulder-clay, in one place 70 feet thick, above the ' muck ' represents the 

 Polandian boulder-clay, and the bottom clay, rarely more than 3 or 4 feet thick, 

 the Saxonian glaciation ; but this reading is quite contrary to the usual relations 

 of the boulder-clays assigned to these epochs ; and, indeed, the whole case is too 

 indefinite to carry any weight. 



Another peaty deposit to which an interglacial age has been assigned was 

 observed many j'ears ago near Macclesfield by Dr. J. D. Sainter,** but in this 

 instance the bed occurred above all the boulder-clays, and was covered only by a 

 few feet of coarse Ijouldery gravel, which, from its topographical position, is 

 probably of fluviatile origin and of late-glacial or post-glacial age. 



Northern Counties.- — In Northumberland and Durham, so far as I am aware, 

 no indication of the Helvetian interglacial epoch is forthcoming. The boulder- 

 clays, with their interbedded sands and gravels, are like those of the North 

 Yorkshire coast, and have received similar explanation. Dr. D. Woolacott,^ in 

 his recent description of glacial sections in Northumberland, remarks: ' So far as 

 the available evidence . . . goes there does not seem to be anything pointing to 

 an interglacial period or periods. The deposits of sand and sandy clay inter- 

 calated in the true boulder-clay are, as a rule, most irregular in position, and vary 

 laterally in thickness.' 



Southern Emjland. — In the South of England, beyond the area of actual 

 glaciation, evidence for an interglacial epoch has been brought forward from two 

 or three localities, where deposits of very limited extent, partly of marine and 

 partly of freshwater origin, have yielded a fauna and flora indicative of com- 

 paratively warm conditions. 



' In G. F. Wright's Man and the Glacial Period (London, 1892), pp. 1 45-153, and 

 in H. Carvill Lewis's Glacial Geology of Great Britain and Ireland. (London, 1894), 

 pp. 394-434. 



' O]}. cit., and Quart. Juvrn. Geol. Soc, vol. xxxi. (1875), pp. 56-99. 



' Quart. Jovrn. Gcol. Soc, vol. xxviii. (1872), pp. 471-491. 



* ' The Glacial Deposits of Northern Pembrokeshire.' Trans. Hoy. Soc. Edinlurgli, 

 vol. xli. (1904), pp. 53-97. 



'■" Quart. Journ. Geol. Soc, vol. xviii. (1862), pp. 274-7. 



" Jbid., vol. xix. (1863), pp. 19-31. 



' Ibid., vol. xxxvii. (1881), pp. 29-39. 



' Geological Rambles round Macclesfield (Macclesfield, 1878), pp. 65-67, 



• Quart. Journ. Geed. Soc, vol. Ixi. (1905), p. G8. 



