XIV.—On the Syenite Veins which traverse Mica Slate and Chalk at Goodland Cliff and Torr Eskert, to the south of Fair Head, in the County of Antrim.

Abstract

The geology of the northern portion of the county of Antrim, has been often treated of; but there are several interesting facts, which have apparently escaped the attention of preceding observers. One of the most important was described by me in the Geological Section at the late meeting of the British Association in Dublin; and I have since revisited the place, accompanied by my friends Professor Sedgwick and Mr. Murchison, at whose request I have prepared the following memoir for the Geological Society*. The part of Antrim to which this paper refers, is situated between Fair Head, on the north, and Cushleake Mountain, on the south. The geological structure of the country is exhibited in the accompanying section, No. 1. It will be seen, that mica slate forms the substratum or base of the country; that secondary rocks, belonging to the coal formation, the new red sandstone, and chalk rest upon it unconformably; and that these secondary rocks are surmounted by an overlying mass of rudely columnar trap, which at its northern extremity, forms the magnificent promontory, called Fair Head. The mica slate is distinctly bedded, and passes from a fine-grained, shining, slaty rock, into a coarsely granular gneiss. Its subordinate strata are hornblende slate and schistose limestone; the latter occurring in several places, particularly on the sea shore, close to the south side of Torr Point, and on the shore at West Torr. At Goodland Cliff, near the northern extremity, the dip is north-west, at an angle of 15°