﻿150 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 5, 



rocks (none of which occur between Saugh Hill and Girvan harbour), 

 are more destructible than the hard greywacke-conglomerate and 

 flagstones which are now to be treated of. On the beach at low-water 

 and to the south of this denudation, ledges of conglomerate, flagstone, 

 and schist are plainly exposed, between the hamlet of Shalloch and 

 the house of Ardwell. Courses of reddish conglomerate are first seen 

 at Shalloch Mill, nearly two miles south of Girvan Water (see fig. 3), 

 in which white quartz pebbles abound, varying in size from a child's 

 head to that of the fist and large playing-marbles. The rock is 

 much broken up and disturbed, and the greywacke-slate, contorted 

 and twisted up like gneiss, is dovetailed between bosses of the 

 -,. • ' . pudding-stone ; some idea of which may 



4 -- A PP earance °f be formed from fig. 4. To the south of 

 the Conglomerate and Shalloch Mill the greywacke-flagstones are 

 Grey wacke at Shalloch vertical and gtrike 2Q o N> of E and in 



this band of conglomerate are broken frag- 

 yi^y /pyf^iM ments of an older greywacke than that 



jdl — 'i/Mmk with which it is associated. Then follows 



2 * 2 a succession of vertical flagstones, some- 



2*. conglomerate or Haggis-stone. wna t dislocated, and after them another 



band of conglomerate, the contents of 

 which are rather more brecciated and angular. This conglomerate, 

 replete also with white quartz pebbles, is different from one to be 

 presently described, and is apparently of about the same character 

 as the conglomerate-band above noted in the Saugh Hill section 

 (fig. 2). It runs out in a bold scar called Kellie Rock, visible at low- 

 water, and exhibits the most perfect passage into, and conformity 

 with, the greywacke-flagstone and schists. 



These latter beds are exhibited at intervals all along the shore, and 

 as you advance to Kennedy's Pass, they are not only traceable at 

 low-water, but jut out upon a grassy flat between the hills and the 

 shore, like the tombstones of a closely tenanted churchyard, all per- 

 fectly parallel to each other, and all having the chief strike of this 

 Silurian tract, viz. from E.N.E. to W.S. W. Here and there they 

 are cut through by trap-dykes : occasionally the line of strike is 

 distorted, and, as they approach the powerful conglomerates and 

 trap-rocks of Byne Hill and Kennedy's Pass, they offer many cur- 

 vatures and fractures, some of which are represented in figs. 4, 5, 

 and 6. 



Figs. 5 & 6. — Appearance of the Greywacke Flagstone North of 

 Kennedy s Pass. 

 Fig. 5. Fig. 6. 



It is in the central portion of these strata (1), both in flagstones 

 and in geodes, either of a slightly calcareous black schist, or in parts 

 an earthy limestone, that Alexander MacCallum has found at various 



