Page:Quarterly Journal of the Geological Society of London, vol. 35.djvu/862

722 PROE. E. HULL ON THE DINGLE BEDS AND Dr. Hicks expressed his conviction, that the great series of truly metamorphic rocks in Ireland are not of Lower Silurian, but of Pre-Cambrian age. He further stated that a portion of the beds regarded as of Upper Silurian age by the author might belong to the Lower Silurian. Prof. Ramsay remarked that Devonshire is still partly a terra in- cognita to the geologist, and that as soon as godd ordnance maps of the country are produced a completely new geological survey of the country must be made. He had found, both in "Westphalia and North America, that strata regarded as Lower Devonian are really Upper Silurian. He regarded the argument of Prof. Hull as nearly convin- cing. The Lower Old Red Sandstone has not the same relations to the Upper Old lied Sandstone in Ireland that the beds called by the same names in Wales and Scotland have. In the former case the Lower Old Red Sandstone of Prof. Hull is equivalent to the Upper Old Red of Scotland, which lies unconformably on the Lower Old Red of that country. In the Lower Old Red Sandstone of Scotland bands of rock, with Graptolites and Upper Silurian fossils, have been found by Prof. Geikie. He thought that the Upper Old Red Sandstone of Griffith had as much right to be called Carboniferous as Devonian. These points only confirmed the views of Prof. Hull. Mr. Ussher stated that there is a perfectly conformable series between the Foreland Grits and the Culm-measures of Devonshire. He thought that Devonshire must still be regarded as affording a typical series. Mr. Jttejjs-Browne wished to ask a few questions. Prof. Hull's argument appeared to be that, because rocks of a certain character occurring in the Dingle promontory were found to be absent in the Inveragh promontory, it was therefore to be assumed that there must be an unconformity in the latter district as well as in the former ; and proofs of an apparent overlap were adduced in support of this. But the evidence brought forward was mainly of a theoretical nature ; the explanatory section showing the possible overlap was not sup- ported by any actually observed section in which an overlap was visible. He would like to be assured on what evidence the Glen- gariff Grits were correlated with the Dingle beds, and why the Upper Old Red Sandstone was banished from the neighbourhood of Sneem and Kenmare, as well as from the head of Bantry Bay, though it was laid down on the maps of the Geological Survey of Ireland and described in the ' Memoirs.' The succession of rocks in the Dingle district was so different from that in the country south of Dingle Bay, that it was really doubtful whether the two series could be compared. Pew men had gained a greater knowledge of the S.W. of Ireland than the late Mr. Jukes, whose views Prof. Hull had quoted ; but Mr. Jukes had not been able to discover any evidence of discordant stratification in the series of rocks referred to. The Author insisted that in a number of sections the Lower Carboniferous Slate and Upper Old Red Sandstone are seen lying directly upon the Glengariff Grits. In reply to Prof. Ramsay,