Page:Quarterly Journal of the Geological Society of London, vol. 35.djvu/839

54. On the Geological Age of the Rocks forming the Southern Highlands of Ireland, generally known as "The Dingle Beds" and "Glengariff Grits and Slates" (Jukes). By Professor Edward Hull, LL.D., F.B.S., F.G.S., Director of the Geological Survey of Ireland. (Read April 9, 1879.)

Contents.

I. Introduction.—Views of previous authors. Charles W. Hamilton, Thomas Weaver, Sir R. Griffith, Rev. Prof. Haughton, Professor J. B. Jukes, and J. W. Salter, G V. Du Noyer, John Kelly, Sir R. I. Murchison, The Geological Survey of Ireland.

II. Reexamination of Sections. Dingle Promontory—succession of beds. Evidence from fossils. Parkmore-Point conglomerate. Killarney, Kenmare, Sneem, and Glengariff districts. Supposed conformity of the Glengariff series and the Carboniferous beds not proven.

III. Comparison with Sections in Galway and Mayo. Upper Silurian Rocks of West Galway and Mayo. Table of representative beds. Volcanic rocks. Plant-remains.

IV. Relations of the Upper Silurian series of the South-west of Ireland to those of the Silurian region of England. Table of supposed representative beds. Conclusions from above.

V. Relations of the Old Red Sandstone to the " Dingle beds &c." Lower and Upper Old Red Sandstone of the South of Ireland. Suggested relations to the Devonian rocks.

VI. General conclusions.

 

I. Introduction.

The geological age of the formations which rise into the highest elevation in the South of Ireland, and form the central masses of the promontories which jut out far into the Atlantic in the counties of Kerry and Cork, has been long a subject of controversy. They have been referred by successive authors to the Silurian, Devonian, and Old Red Sandstone periods. While I would refrain from speaking dogmatically on a question which may be incapable of absolute demonstration, I wish to place before the Society the reasons which have induced me to agree with those who have referred these beds to the Upper Silurian age. Before proceeding to the discussion of those points which seem to me to bear directly upon the question at issue, I will briefly notice the views expressed by previous authors on the subject.

 

Views of Previous Authors.^[1]

1838. In this year Mr. Charles W. Hamilton, in a paper entitled "An Outline of the Geology of part of the County of Kerry"^[2], described the coast sections of the Dingle promontory, noticing the beds with Silurian fossils and the overlying slates and grits, and

1. A fuller account of these views than that here presented was drawn up by the author, but by order of the Council it has been curtailed.
2. Journ. Geol. Soc. Dubl. vol. i. (1838).