516 Notices of Memoirs — C. I. Gardiner — Igneous Rocks,Galway. 



often extend from top to bottom of cliffs ranging up to more than 

 100 feet in height, and in some cases continue horizontally for over 

 100 yards. They are almost completely filled with blocks of lime- 

 stone, of all sizes up to masses weighing hundreds of tons, which have 

 fallen from the roof and sides, but also contain a little interstitial 

 Triassic material in situ. The formation of the cavities, therefore, 

 preceded the deposition of the Trias, and took place during the long 

 period represented by the great unconformity between tbe latter and 

 Carboniferous rocks. In this district, most, if not all, of the succeeding 

 younger formation (tbe Trias), deposited on the upper surface of the 

 limestone, has been removed, but there is evidence tbat that surPace 

 was a base-levelled plane. This belief, however, does not invalidate 

 the conclusion that such plane^ are devoid of contemporaneous swallow- 

 holes, because the plane which is believed to have existed in this case 

 must have truncated some of the breccia-filled cavities, and therefore 

 have been of later origin. 



III. — Investigation of the Igneoits and Associated Eocks of the 

 Glensaul and Lotjgh Naeooey Akeas, Co. Galway.^ Ey C. I. 

 Gakdinee,.- 



ME. C. I. GAEDINEE and the Secretary visited Connemara in 

 April and completed their field work on the Glensaul district, 

 commencing, in addition, to map the Lough jSTafooey district. 



The Glensaul district is a small one, measuring only about 2x1 

 miles. It is about 3 miles south-west of the southern extremity of 

 the Tourmakeady district, recently described,^ of whicb it is clearly 

 a continuation, the type of sedimentary rock met with in the two 

 being practically identical. The general succession is : — 



III. ^Bala Beds — conglomerate and sandstone. These have not been studied. 

 II. Llandeilo Beds. 



(5) Calcareous gritty tuff, passing in places into fairly 

 pure limestone, and enclosing bands and patches 

 of limestone breccia and bands of highly f ossili- 

 ferous limestone, which in some cases has been 

 shattered by earth movement . . . Thickness doubtful. 



(4) Very coarse tuff or breccia mainly composed of 



felsite fragments ...... 750 feet. 



(3) Tuff coarse and fine with occasional patches of 



calcareous beds 150 feet. 



(2) Great felsite sill of Tonaglanna and Greenaun . 1'200 feet. 



(1) Tuff with some grit . 600 feet. 



I. Arenig Beds. 



(4) Coarse grit 150 feet. 



(3) Fine grit and tufi associated with black chert, 



graptolitic shale, and a prominent band of 



breccia 30 feet thick Thickness doubtful. 



(2) Coarse grit 110 feet. 



(1) Coarse conglomerate . . . . ... About 600 feet seen. 



' Abstract of Paper read at British Association Meeting, "Winnipeg, in Section (C) 

 Geology, August, 1909. 



2 Eeport of the Committee, consisting of Professor W. "W. Watts (Chairman), 

 Professor S. H. Reynolds (Secretary), Mr. H. B. Muff, and Mr. C. I. Gardiner. 

 (Drawn up by Mr. C. I. Gardiner and the Secretary.) 



3 Quart. Jouru. Geol. Soc, 1909, vol. Ixv, pp. 104-53. 



