46 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [NoV. 23, 



some time resident in Norway, and now in Canada, di'ew atten- 

 tion to the striking resemblance between the Norwegian primitive 

 gneiss formation, as described by Naumann and Keilhau, and 

 observed by himself, and the Laurentian, including the Labrador 

 group ; and the equally remarkable similarity of the lower part of 

 the primitive slate formation to the Huronian series, which is a 

 third Canadian group. These primitive series attain a great thick- 

 ness in the north of Europe, and constitute the main features of 

 Scandinavian geology. 



In Bavaria and Bohemia there is an ancient gneissic series. 

 After the labours in Scotland, by which he was the first to establish 

 a Laurentian equivalent in the British Isles, Sir Roderick Murchi- 

 son, turning his attention to this central European mass, placed it 

 on the same horizon. These rocks, underlying Barrande's Primordial 

 zone, with a great development of intervening clay-slate, extend 

 southward in breadth to the banks of the Danube, with a j^revaUing 

 dip towards the Silurian strata. They had previously been studied 

 by Giimbel and Crejci, who divided them into an older reddish gneiss 

 and a newer grey gneiss. But, on the Danube, the mass which is 

 furthest removed from the Silurian rocks being a grey gneiss, Giim- 

 bel and Crejci account for its presence by an inverted fold in the 

 strata, while Sir Roderick places this at the base, and regards the 

 whole as a single series, in the normal fundamental position of the 

 Laurentian of Scotland and of Canada. Considering the colossal 

 thickness given to the series (90,000 feet), it remains to be seen 

 whether it may not include both the Lower and Tipper Laurentian, 

 and possibly, in addition, the Huronian. 



This third Canadian group (the Huronian) has been shown by 

 my colleague, Mr. Murray, to be about 18,000 feet thick, and to 

 consist chiefly of quartzites, slate-conglomerates, diorites, and lime- 

 stones. The horizontal strata, which form the base of the Lower 

 Silurian in Western Canada, rest upon the upturned edges of the 

 Huronian series, which, in its turn, unconformably overlies the 

 Lower Laurentian. The Huronian is believed to be more recent 

 than the Upper Laurentian series, although the two formations have 

 never yet been seen in contact. 



The united thickness of these three great series may possibly far 

 surpass that of all the succeeding rocks, from the base of the Paleo- 

 zoic series to the present time. We are thus carried back to a 

 period so far remote, that the appearance of the so-called Primordial 

 fauna may by some be considered a comparatively modern event. 

 We, however, find that, even during the Laurentian period, the same 

 chemical and mechanical processes which have ever since been at 

 work disintegrating and reconstructing the earth's crust were in 

 operation as now. In the conglomerates of the Huronian series 

 there are enclosed boulders derived from the Laurentian, which 

 seem to show that the parent rock was altered to its present cry- 

 stalline condition before the deposit of the newer formation, while 

 interstratified with the Laurentian limestones there are beds of 

 conglomerate, the pebbles of which are themselves rolled fragments 



