OVERLYING ROCKS OF LOCH MAREE. 813 



(b) called by Prof. Nicol " red sandstone/' and by Sir E. Murchison 

 " Cambrian conglomerates and sandstones." They appear to have 

 been, for the most part, shore or shallow- water accumulations ; and 

 fragments of the underlying gneiss rocks are abundant in them as 

 pebbles or masses but slightly rolled. Associated with these, how- 

 ever, are other masses which do not seem to have come from the 

 immediate neighbourhood, or at least from any of the areas which 

 I visited. These are chiefly bits of greenish, purplish, and reddish 

 slates, schists, jasper, &c, similar in many respects to those found 

 in the Cambrian conglomerates in Wales, and which were there 

 undoubtedly derived from the underlying Pebidian beds. It is 

 therefore quite possible that in some other areas not far distant re- 

 presentatives of these Welsh pre-Cambrian rocks may also be found. 



Looking at the conglomerates »and sandstones in a penological as 

 well as stratigraphical point of view, I must say they appear to me 

 to be on the whole exceedingly like the more shallow portions of 

 the Cambrians of Wales, and to hold an equivalent position. The 

 conditions at the time they were deposited were undoubtedly un- 

 like in some respects, but generally they were the same. The lines 

 of depression appear in both cases to have been alike and probably 

 synchronous ; but in Wales the submergence was greater, and hence 

 the accumulations were, for the most part, of finer materials. The 

 succeeding beds (c), quartz rocks, which, according to Sir E. Mur- 

 chison, lie unconformably on the Cambrians, seem so here, though 

 Prof. Nicol holds a contrary view. The dip and the general manner 

 in which they lie are, however, imperfectly shown in Sir E. Mur- 

 chison's and Mr. Greikie's section ; and neither they nor Prof. Mcol 

 mention the so-called fucoidal beds (c 1 ) which interstratify the 

 quartz rocks here, and which they particularly refer to in some 

 other sections. These are dark grey flaggy bands, of some thickness, 

 and contain on their surfaces peculiar fucoidal-looking markings, 

 similar to some occasionally found in the more shallow beds of the 

 Lingula-flagsand Tremadoc Eocksin Wales. These markings, of course, 

 are not in any way sufficient to enable us to attempt to correlate 

 the beds ; but such facts are worthy of being remembered if only as 

 guides to the conditions present at the time, and of the possible 

 contemporaneity of changes affecting distant areas. Indeed it 

 is almost impossible, when looking at these thick beds made up of 

 pure quartz grains also, not to call to mind the Stiper Stones of 

 Shropshire, which, if our reasoning is correct, must have been 

 formed about the same period. 



The second band (c 2 ) is probably nearest in position to the Stiper 

 Stones ; but the breaks above and below these quartz rocks, if they 

 are really such, with the intermediate sediments, must actually 

 bridge over the whole of the periods included under the names 

 Menevian, Lingula-flags, Tremadoc, Arenig, and which are repre- 

 sented in Wales by from 8000 to 10,000 feet of sediments, with 

 numerous and varied faunas. 



Upon the quartzites are the limestone bands (d), occupying chiefly 

 the sloping ground on the west side of Glyn Laggan ; and the limestone, 



