76 MK. GAEDINER AND PROP. REYJSOLDS ON THE [Feb. 1912,. 



description of it is given in the Memoirs of the Geological Survey.^ 

 The igneous rocks are referred to as being everywhere felsite ; the 

 presence of ash is mentioned; and allusion is made to the finding of 

 Llandovery fossils at several points on the southern side of the 

 peninsula. 



In the ' Annual Eeport of the Geological Survey for 1896 ' 

 (pp. 49-51) a general account of the igneous and associated rocks 

 of the Tourmakeady, Glensaul, and Lough ]S"a£ooey districts is 

 given; and, in his 'Ancient Yolcanoes of Great Britain,' Sir 

 Archibald Geikie (vol. i, 1897, p. 251) briefly alludes to the Lough 

 Xafooey district, but gives no details. The papers by Mr. J. K^ 

 Ivilroe " ' On the Silurian & Metamorphic Rocks of Mayo & j^orth 

 Galway ' ; by Messrs. E. G. Carruthers & H. B. Maufe ^ on ' The 

 Lower Palaeozoic Bocks around Killary Harbour ' ; and by the 

 authors of the present communication upon the neighbouring 

 districts of Tourmakeady ^ and Glensaul'^ have some bearing upon 

 the Kilbride district. 



At the meeting of the British Association for the Advancement 

 of Science at Dublin in 1908, a Committee was appointed *^ to 

 investigate the igneous and associated rocks of the Glensaul and 

 Lough Xafooey districts (Galway) ; and, following a report on the 

 Glensaul district presented at Winnipeg " in 1909, a preliminary 

 account of the geology of the Kilbride peninsula was read at the 

 Sheflield "* meeting of the Association in 1910. The substance of 

 the general account of the structure of the peninsula there given 

 may be repeated in a slightly amplified form here. 



The southern and eastern part of the peninsula consists in the 

 main of Llandovery and Wenlock grits and flags, dipping with great 

 regularity in a direction varying from east to south- south-east. 

 These strata are associated with a large intrusion of lime-bostonite, 

 some smaller ones of labradorite-porphyrite, and an extensive series 

 of small dolerite sills. Some of the beds are exceedingly fossiliferous, 

 these being on the same horizon — Ujoper Llandovery — as those to 

 which we referred,*' in our paper on the Tourmakeady district, as 

 occurring in the neighbourhood of Trean. The northern and 

 western parts of the peninsula consist principally of a great series 

 of igneous rocks — quartz-felsite, pillow-lavas (spilites), and coarse 

 tufts or breccias. These rocks are clearly comparable with the 

 igneous series of the Tourmakeady and Glensaul areas, and a 

 further resemblance lies in their association with cherts and beds 



1 Mem. Geol. Surr. Ireland, Explan. Sheets 93 & 94, with part of Sheets 83, 

 84, & 103 (1878) pp. 114-16 : also Explan. Sheet 95 (1870) pp. 43-45. 

 - Proc. Roy. Irish Acad. vol. xxvi, sect. B, no. 10 (1907) pp. 1,29-60. 

 ■^ 'Irisli Naturalist ' vol. xviii (1909) pp. 7-11. 



4 Q. J. G. S. vol. Ixv (1909) pp. 104-53. 



5 Ibid. vol. Ixvi (1910) pp. 253-79. 



•^ Consisting of Prof. W. W. Watts, Mr. H. B. Maufe, and the authors of 

 the present paper. 



' Rep. Brit. Assoc. (Winnipeg) 1909, p. 163. 

 ^ Ibid. (Sheffield) 1910, p. 110. 

 9 Q. J. G. S. vol. Ixv (1909) p. 126. 



