the limestone. The uppermost part of this ridge seems to consist of one great uninterrupted bed of limestone, some hundreds of feet in thickness, or rather, of an accumulation of beds; well marked horizontal lines being observed to extend in a parallel direction along the precipice. It is also completely traversed by perpendicular fissures.
Below this great mass a bed of quartz or sandstone, of considerable thickness, is to be seen running parallel with, and separating the incumbent from a similar subjacent body of limestone. I did not observe whether this alteration is carried further, but it is probable that it might be discovered in some other parts of the ridge. The limited extent of my investigation also prevented me from determining the position of the limestone relative to the great sandstone or quartz formation; whether it lies upon the sandstone which rises to the south of it, and under that which rises to the north, or whether it is a partial deposit, occupying the valley alone, and incumbent on the whole mass. The examination of an extensive tract of very difficult access, would be requisite to decide this question, as well as to ascertain the magnitude of its extent, and the nature of the limits by which it is bounded. Yet, the appearance of a quartz bed alternating with it, renders it probable that it is also interposed among some of the larger masses. The beds which I have described are elevated to a considerable angle, and although in some places their section forms a continuous and even line, in others they are curved and broken, and tossed about to such a degree, that their stratified position can scarcely be perceived. The stone itself is a dark grey or nearly black bituminous limestone, of an earthy aspect, and minute granular fracture, smelling offensively when rubbed. I did not any where observe animal remains in it. In many places it is fissured into small fragments, the intervals of which
Vol. II.3 f
