THE 
GHOLOGICAL MAGAZINE. 
No. IX.—MARCH 1865. 
ORIGINAL ARTICLIES. 
fe 
I. On toe Laurentian Rocks or Britain, BAVARIA, AND 
Bouemtia. 
By Sir Ropericx I. Murcutson, K.C.B., F.R.S., Director-General of the Geological 
Survey of Great Britain, &c. &e. 
LARGE portion of the last number of the Quarterly 
Journal of the Geological Society (February Ist) is justly 
devoted to the important subject of the Laurentian or oldest 
known stratified rocks, the elaboration and naming of which in 
North America were, it is well known, accomplished by Sir 
William Logan and his associates. On this occasion a memoir 
by that eminent geologist naturally leads the way, whilst, in 
the subsequent articles, the nature and structure of the Hozoon 
Canadense, which has been found in these rocks, are ably 
developed by Drs. Dawson, Carpenter, and Sterry Hunt. 
The British rocks which I have shown to be of Laurentian 
age occupy striking headlands in Sutherland and Ross, where 
they are, as I proved, unconformably surmounted by both 
Cambrian and Lower Silurian rocks. At first I termed these 
lower rocks ‘ Fundamental Gneiss.” They were then described 
as being completely dissevered from all the paleozoic rocks, not 
only by unconformability, but also by having an entirely di- 
vergent strike or direction, namely, from SE. to NW., being at 
right angles to that of all the superjacent deposits of Britain. 
The announcement of a direction from SE. to NW. in these 
underlying rocks was in itself as great a novelty in our insular 
geology as the introduction of a lower base of our whole 
geological series than had hitherto been recognized. 
After several years of preceding researches, I brought these 
VOL. II.—NO. IX. © H 
