Page:Transactions of the Geological Society, 1st series, vol. 3.djvu/212

 point bold and lofty precipices of that rock take place of the chalk and red sandstone in the higher region, and, stretching to the north, constitute the well-known promontory of Fairhead, which bounds Murloch bay on that side.

It is greatly to be regretted, that the convulsions of which this bay appears to have been the theatre, having covered the regular strata with shattered fragments and piles of ruin, heaped together in the wildest confusion, have thrown an impenetrable obscurity over its structure, which, from the narrow space in which so many formations are successively exhibited, must be regarded as more important than that of any other point on this coast.

From this cause it is impossible to ascertain the exact relations of the greenstone at this point with the chalk and red sand. The general appearance is, that the mass of greenstone abuts abruptly against that of the sandstone, both being placed at the same level. It has been said that the greenstone and sandstone are here to be observed, alternating with each other. (See notes to the poem of the Giant's Causeway, by Mr. Drummond.) But it may be questioned whether this representation is not founded on a hasty view of some of the subsided masses above mentioned. The greenstone, where it first appears, exhibits two columnar strata, separated by a bed of amorphous greenstone.

Near the point where the greenstone is lost, we observed the traces of adits formerly driven into the sandstone in search of coal, beds of which appear to occur among the lower members of the sandstone formation. The position of one of these adits is such as to afford some countenance to the supposition, that the greenstone and sandstone here alternate; and, since a thin horizontal bed of trap certainly does occur interstratified with the coal measures on the other side of Fairhead, such an opinion cannot be rejected without further examination.