Note 312 — Chapter XLII · THE BASIC SILLS OF THE BASALT-PLATEAUX
Reading edition
"Address to Geological Society of Dublin, 1835," p. 13, Jour. Geol. Soc. Dublin, vol. i. The varieties of the Portrush rock were described by the late Dr. Oldham, in Portlock's Report on the Geology of Londonderry, p. 150; see also the same work for Portlock's own remarks, p. 97.