Note 426 — Chapter XLVII · THE ACID BOSSES OF MULL, SMALL ISLES, ST. KILDA, ARRAN AND THE NORTH-EAST OF IRELAND

For an early account of the Antrim trachytic rocks, see Berger, Trans. Geol. Soc. iii. (1816), p. 190. Professor Hull has described the Tardree rock in the Explanation to Sheets 21, 28 and 29, Geol. Survey of Ireland (1876), p. 17, and has supposed it to be older than the basalts, referring it to the Eocene period (Physical Geology and Geography of Ireland, 2nd edit. (1891), pp. 87, 95). Duffin (quoted by Mr. Kinahan) believed that "the trachytes occur at the centre of eruption, and were probably poured out at the end of the outburst." Du Noyer also (quoted by the same writer) thought them to be newer than the plateau-basalts, and to have lifted up masses of these rocks. Mr. Kinahan himself (Geology of Ireland, p. 172) has pointed to the absence of any rhyolitic fragments between the basalts as an argument against the supposed antiquity of the acid protrusions. A petrographical account of the Tardree rock is given by Von Lasaulx in the paper already cited, Tschermak's Min. Pet. Mittheil. (1878), p. 412. A more elaborate discussion of the petrography by Prof. Cole will be found in the Memoir above referred to (Scientif. Trans. Roy. Dublin Soc. vol. vi. 1896), and the geological relations of the rocks are discussed by him in another shorter paper, Geol. Mag. (1895), p. 303. See also Mr. M'Henry on the trachytic rocks of Antrim, Geol. Mag. (1895), p. 260, and Proc. Geol. Assoc. vol. xiv. (1895), p. 140.