﻿428 DK. C. A. MATLEY OX THE [Aug. I908, 



come in to the north, the angles of dip become lower, and the beds 

 roll over in a series of shallow folds lor a distance of 500 yards. 

 Marine fossils are abundant in certain limestone-beds in this series, 

 and include a CijathcLvonia-isLwna. The black calcareous shales 

 associated with them contain plant-remains {Calamites, Lepidoden- 

 dron Rliodeanum, etc.), lamellibranchs {Posidonomya Becherl and 

 Fosidoniella Icevis), and Nomismoceras. The beds appear to belong 

 to some portion of the Posidonomya-h\m.e&tone'B> with perhaps some 

 of the beds of the Loughshinny Black Shales. 



These beds are cut off from the rocks farther north at a small 

 nameless cove (called in this paper Limekiln Cove, from the sub- 

 stantial limekiln built at the head of it) by one or more faults, 

 along the inland course of which copper-ore was mined many years 

 ago. The Geological-Survey Memoir gives all the information 

 concerning these mines that could be obtained by G. Y. Du Noyer 

 in 1849, from which it appears that there were three sub-parallel 

 lodes, 50 feet apart, with a strike 30° north of east and a hade 

 to the south.^ Below high-water mark I found that a reef of 

 quartz, in places 10 to 14 feet wide, runs out to sea in the direction 

 mentioned ; and, as it contains some traces of copper, it apparently 

 represents one of the lodes mentioned, probably the southernmost 

 and principal lode. 



(C) Dibunophyllum-ljimestoneSf north of Limekiln Cove. 



The beds on the north side of Limekiln Cove are disposed in a 

 well-marked dome, with dips ranging up to 35^. The lowest 

 40 feet of the beds exposed consist of light-brown dolomite, above 

 which comes, on the south side of the anticline, 60 feet of limestone, 

 in beds up to 5 feet thick. A quartz-pebble may be found 

 occasionally in some of the upper beds, and nodules and seams of 

 chert also occur. Shale-bands are quite rare, and the beds are 

 quite distinct lithologically from those that are found to the south 

 of the quartz-reef fault. Numerous quartz-veins and cavities lined 

 with quartz -crystals occur in these limestones, in the neighbourhood 

 of Limekiln Cove. The bedding is very regular. 



The beds above the dolomite on the north side of the anticline 

 are more shaly than those on the south side, and they also contain 

 several beds of fine conglomerate, pebbly limestone, and pebbly 

 shale ; the inclusions consist of quartz-pebbles and fragments of 

 Silurian rocks. The limestones here are also less regularly bedded 

 than those on the south side of the anticline, being ordinarily 

 lenticular in form, and they were certainly laid down in shallower 

 water than those to the south. This fact, together with the 

 abundance of detritus in the beds here, points to the proximity of 

 land in a northerly direction. A massive limestone lies above the 

 conglomeratic beds, and is itself in part conglomeratic. It contains 

 numerous brachiopods similar to those recorded from the Curkeeu- 



^^ Expl. Sheets 102 & 112, Mem. Geol. Surv. Ire]. 2nd ed. (1875) p. 70. 



