Reports and Proceedings — Geological Society of London. 139 



Geological Society of London. 



L— January 22nd, 1902— J. J. H. Teall, Esq., M.A., F.R.S., 



President, in the Chair. The following communications were 



read : — 



1. " The Fossiliferous Silurian Beds and Associated Igneous Rocks 



of the Clogher Head District (County Kerry)." By Professor 



Sidney H. Reynolds, M.A., F.G.S., and Charles I. Gardiner, Esq., 



M.A., F.G.S. 



After a brief account of the bibliography of the district, the 

 authors proceed to give a detailed description of the coast from 

 Dunquin past Clogher Head to Coosglass (south of Sybil Point), 

 and of the western side of Smerwick Harbour. They next deal 

 with the inland exposures, which are not very frequent, but include 

 considerable rock-masses at Croaghmarhin and Minaunmore Rock. 

 The rocks consist of sandstones, slates, calcareous flags, ashes and 

 ashy conglomerates, rhyolitic lava-flows, and various intrusive rocks. 

 The general structure is an S-shaped fold, inverted towards the 

 north so that the dip of the beds is approximately south-easterly, 

 and the oldest beds occur to the north, at Coosglass. Both 

 anticline and syncline are faulted, and a patch of Old Red Sandstone 

 is caught in under the synclinal thrust at Coosmore. Fossils, mainly 

 corals, brachiopods, lamellibranchs, and gasteropods, are fairly 

 abundant ; but trilobites are rare and graptolites absent. The 

 whole of the fossiliferous rocks are of Silurian age ; the majority 

 of those exposed on the coast are of Wenlock or Wenlock- Llandovery 

 age, while the majority of those exposed inland are of Ludlow age. 

 The general classification is as follows : — 



Lower Devonian Dingle Series. Feet. 



Ludlow ( 5 . Croaghmarliin Beds : calcareous sandstones and 



flags of Ludlow age ? 1,000 



4. Drom Point Beds about 600 



3. Bed sandstones and ashes, with, green ash at 



the top 350 



2. Clogher Head Series : calcareous flags and 

 slates, with abundant contemporaneous 



igneous rocks 550 



Wenlock ( ^' ^^^'^'it^r's Cove Beds : chiefly calcareous flags, 



Llandoyeky ^^t^ ^ subordinate development of contem- 



\ poraueous Igneous rocks 2,300 



? Smerwick Beds. 



Contemporaneous volcanic rocks are first met with low down in 

 the Wenlock-Llandovery Series, and reach their maximum in the 

 Wenlock Series, especially in the southern part of the area. There 

 are ashes but no lavas in the Ludlow. The volcanic rocks are all 

 of acid character, and include nodular, banded, and non-banded 

 rhyolites, with tuffs and ashes both coarse and fine. The Dingle 

 Beds appear to be conformable, but movement occurred before the 

 Old Red Sandstone Conglomerate was laid down, and the overfolding 



{ 



"Wenlock 



