642 t Proc - B.N.F.C, 



lignite along the shore, such as are in other places associated with 

 the Lough clays. Still more important is a reference by Portlock 

 to a "stiff bluish clay" at the mouth of the Ballinderry River, 

 under 6 feet of alternate layers of sand and imperfect lignite. 

 Even if we suppose the lignite there to have been carried along 

 the river course to the mouth (as is most probable), its source, a 

 bed of lignite in situ, must have been exposed to erosion by the 

 stream ; which, taken conjointly with the conglomerate at Coagh, 

 brings us to the same conclusion as that above mentioned, viz., 

 the occurrence of a representative of the Interbasaltic Zone near 

 the lake-level on the west side, as on the east. 



Portlock also mentions that the stiff bluish clay beneath the 

 lignite rests upon finely crystalline basalt. It may be that this 

 clay is (like that at Claremont) lithomarge, and the basalt under it 

 Lower Basalt; but this cannot with any degree of certainty be 

 asserted. Taking, however, the indications available and certain, 

 it is not improbable that the recent subsidence which submerged 

 the portion of the present Bann course, furrowing the lake bottom,* 

 has concealed, through a relative rise of the water, and by means 

 of a wider spread of recent lake deposits, an outcrop of the inter- 

 basaltic beds around the northern half oi the lake. 



We are certain that the Lower Basalt extended southward as 

 far as Claremont, and in but trifling thickness at Templepatrick ; 

 but can the same be said of any point further south ? A boring 

 was put down at Sandy Bay through lignite and clay beds to 76 

 feet 6 inchest without piercing basalt. Hardman represents a 

 great thickness of Lower Basalt under Lough Neagh, but this 

 entirely eludes us ; so far from there being a wide-spreading 

 outcrop of basalt along the shallow synclinal trough south-west- 

 ward, which we might expect, upon such a hypothesis, there is 



♦Pointed out by Sir A. Geikie, D.C.L., LL. IX, F.R.S., etc., in "Ancient 

 Volcanoes," Vol. II., p. 451. 



fllardman, "On the Age and Formation of Lough Neagh." Proc. Roy. 

 Geo. Soc. I., Vol. IV., p. 175. 



