1883-1884.] 277 



On the north face, the laminated beds with plants occupy quite 

 two-thirds to one-third conglomerate. In a cutting on the 

 railway just above, there is a seam of lignite above a layer of 

 basalt, and three or four feet of plant bearing beds unrepresented 

 in the quarry. The total thickness of the deposit would seem, 

 therefore, to exceed 25 feet, though it is not even then apparent 

 that the base is exposed.* 



It is generally assumed that the Lignites and Iron-ores mark 

 a prolonged period of volcanic repose ; but it does not appear 

 that this was altogether the case, for though the iron-ores are 

 mainly decomposed basalt, rearranged by water, they certainly 

 contain fragments of ash that must have been ejected and fallen 

 directly into them. For a long period there were no lava flows 

 over this district, but the volcanic forces, doubtless, remained 

 active in other respects, and their presence was probably con- 

 tinuously manifest through fumaroles, etc. In the railway cut- 

 ting a little south of Ballypalady, the evidence of fire is start- 

 lingly fresh. A slight hill is cut through, composed of ash or 

 mud which has undoubtedly been subjected for a very long 

 time to a fierce heat. It must have been a burning plain, and 

 presented a scene as desolate as those in the Myvatn district 

 of Iceland, which continuously exhale steam and gas and boiling 

 mud. The colours of the calcined earth shade from bright 

 cherry-red to crimson, with complimentary facets of blueish 

 purple. The mud and ash has assumed, under the prolonged 

 heat, a concentric structure, and presents sections in form of O 

 shaped retorts. These signs intensify towards a core of basalt 

 which forms the centre of the hill. About a mile and a half 

 south, a hill of amygdaloidal basalts, with very rich colouring, 

 is cut through. 



These are approximately on the level of the Ballypalady 

 beds. Some of the latter are very vesicular, especially towards 

 the base of the quarry. There is a total absence of aquatic life; 



* It is quite possible that the beds in the cutting, being separated by a thick dyke 

 from those in the quarry, may be only the same beds brought to a higher level by an 

 upthrow. 



T 



