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XIX.— NOTES ON THE TERTIARY IRON ORE MEASURES, 

 GLENARIFF YALLEY, COUNTY ANTRIM, by 

 PHILIP ARGALL. Plates 16, 17, 18, and 19. 



[Read, April 11th, 1881.] 



Having been for some time engaged at the Iron Mines of 

 GlenarifF, and having paid some attention to the Iron Ore 

 Measures and associated strata, perhaps I may be allowed to lay 

 before the Society some of the notes I have made from time to 

 time, more especially as I am led to believe that the true nature 

 of the iron ore deposits have still to be learned. 



As an introduction, it may be allowable to give a short 

 description of the valley and its rocks. GlenarifF is the south- 

 west land continuation of Red Bay, probably so called from the 

 Red Sandstone cliffs which form its northern shore. 



The glen is perhaps the most beautiful of all those indenting 

 the Co. Antrim. Around the basaltic tipped chalk cliffs rise to 

 heights, in places, of 800 feet, their continuity and colours being 

 broken and diversified by deep ravines, faults, and landslips, and 

 over them in places streams of water fall, forming picturesque 

 cascades, often perpendicular, of from 50 to 300 feet in height ; 

 while in the distance, as a back ground, across the North Channel, 

 is the Mull of Kantire, with its lighthouse, and the Highlands of 

 Scotland. 



At its junction with Red Bay the Glenariff Valley is a mile 

 wide, the red Triassic rocks forming the base of the slopino- 

 undercliffs, on either side, but these rocks are best seen at the 

 north or Waterfoot side, where they rise to a height of nearly 200 

 feet. A quarry was opened in these rocks to procure stone for 

 Red Bay pier ; the rocks being traversed by an interestino- 

 dolerite dyke which throws up numerous shoots and branches as 

 represented on Plate XVI. The main dyke bears N. and S.* 

 and dips 85° to the west. The largest shoot bears also N. and S. 

 but dips east at 75°, and would probably unite or drop into the 

 large one at a moderate depth ; these dykes at low water can be 

 traced for some distance along the shore, standing up in a wall 



* This and other beariugs are magnetic. 

 SciEN. Pkoc, R.D.S. Vol. iii., Pt. iv. 



