Corr—The Rhyolites of the County of Antrim ; with a Note on Bauzite. 81 
remarkable for the caution with which underground features were hinted at, 
rather than sketched in. Some of the more recent sections seem to err, on the 
other hand, in a certain picturesque boldness, for which there may be only limited 
authority in the accurate notes taken in the field. 
Mr. G. H. Kinahan,* in 1878, regarded the rhyolite at Templepatrick as 
intrusive ; but the first reference to the importance of the section was made in a 
communication from Mr. M‘Henry to Sir A. Geikie,t in which the “ trachyte” 
was stated to be intrusive in the Lower Basalts, but to be itself pierced by younger 
basic dykes. Professor Hull} subsequently published a drawing of the eastern 
half of the section, and maintained that the basalt was intrusive in the rhyolite. 
Mr. M‘Henry§ has now given us a concise exposition of his views, with drawings 
of the whole northern face of the quarry. His arguments may be thus sum- 
marised :— 
(1.) The rhyolite (‘‘trachyte”) at the east end is intrusive in the adjacent basalt, 
because it has a columnar structure, radiating inwards from the curved surface of 
junction, with a flow-structure also parallel to that junction. The flint-gravel in 
contact with it, and, in fact, between it and the basalt, is indurated, in contrast 
with its usual loose and more clayey character. (In the figure in the second 
paper cited below, the word ‘“ Basalt” should be transferred from the chalk on 
the left to the mass in the right-hand upper corner. )! 
(u.) At the west end, the rhyolite “has forced its way underneath the basalt 
along the zone of the flint-gravel bed, which it carries on its back, and at one 
place portions of the gravel bed rest both above and below it.” 
(i.) At Ballypalady, the Libert Mine, and other places, conglomerates occur 
between the Upper and the Lower Basalts. These contain pebbles and finer 
débris of rhyolite, and, at Ballypalady, fragments from the Lower Basalt in 
addition. || 
After the appearance of Mr. M‘Henry’s paper, Professor Hull kindly sent me 
some further comments upon the section ; and, with the advantage of the company 
of Miss 8. M. Thompson and Mr. R. Welch, I revisited the Templepatrick quarry, 
feeling that conclusive evidence could be found only in the western portion of the 
section. At the east end, the junction of the rhyolite, gravel, and basalt is not 
* «¢ Geology of Ireland,” p. 162. 
} A. Geikie, ‘‘ Volcanic action, &e.,” Trans. Roy. Soc. Edin., vol. xxxv. (1888), p. 171. 
t ‘Physical Geology and Geography of Ireland,” 2nd ed. (1891), p. 99. 
§ ‘On the Age of the Trachytic Rocks (Rhyolites) of Antrim,” Geol. Mag., 1895, p. 260. Also 
“Sketch of the Geology of Co. Antrim,’ Proc. Geol. Assoc., vol. xiv. (1895), p. 141. 
|| These ‘‘trachytic agglomerates” were previously referred to by Sir A. Geikie, ‘‘ Anniversary 
Address,” Quart. Jour. Geol. Soc. London, vol. xlviil. (1892), Proceedings, p. 168. { 
