54 



PROCEEDINGS OE THE GEOLOGICAL SOCIETY. 



have carefully investigated and thought out any great physical 

 question is at all times difficult ; and perhaps there are few subjects 

 on which men have theorized and differed more than on the history of 

 the globe. For time and life are two subjects that at once arrest the 

 attention of all earnest students. Our knowledge of the commence- 

 ment of either is as indefinite now as in the days of the earliest 

 investigators. With the succession of sedimentary rock-masses 

 in the outer framework of the globe we are perhaps partly familiar, 

 certainly so for given and known areas ; there are, however, exten- 

 sive regions yet unknown and unexplored, and remaining to be corre- 

 lated with the known ; and yearly in the Transactions of our Society, 

 through the researches of our Foreign Members and others, are we 

 reminded how insecure and uncertain is our base, how doubtful our 

 succession, when attempted to be universally applied. Yearly some 

 new light is thrown upon the obscure history of the earliest rocks with 

 which we believe ourselves acquainted. Both the early metamorphic 

 and the lowest Palaeozoic rocks, even in our own small area, are 

 still waiting for final position and classification ; the same may be 

 said of much of Europe, America, Canada, India, and Australia. 



Palaeozoic time in Europe and Britain may have commenced with 

 the deposition of the so-called earliest Cambrian rocks ; but where 

 geographically, we know not — probably far to the west of Ireland 

 and the British Islands, under what is now the deep Atlantic. The 

 north-western coast of Scotland, and Ireland, much of the north-west 

 of England, and North and South "Wales all point to a region where 

 we may believe that the earliest known sedimentary rocks of Western 

 Europe, and their life contents had their commencement or origin. 

 Little can be said here of Archaean time and its rocks as developed 

 on the American continent ; possibly we may recognize and correlate 

 the Archaean system of Dana with our gneissose schists and so-called 

 Laurentian rocks of the north-west coast of Scotland and the 

 Hebrides. 



It would be mere speculation here to attempt to define any strict 

 contemporaneity. We know from the labours of Dana, and the re- 

 searches of Sir William Logan in the field, and of Billings in the 

 study, that two periods or eras of Archaean time are fully represented 

 in North America and Canada : — 1st, the older or Laurentian ; 

 2nd, the Huronian, this latter in all probability represented by 

 our lowest Cambrian, or those beds underlying the Menevian of St. 

 David's, and also constituting the rocks of Harlech, Llanberris, Ban- 

 gor, and the Longmynds. We have hitherto discovered no life-remains 

 in the Archaean rocks of the British Islands, our so-called Lauren- 

 tians having none of the prevalent limestones, Eozoonal or otherwise, 

 of the New -York and Canadian rocks. To trace out the conditions 

 of the northern hemisphere during Lower-Cambrian times, both 

 zoologically and physically, has been and is still one of the most 

 difficult and important problems of modern geological research*. 

 We have long known that the European area was of great extent, 



* Vide Hicks, Geol. Mag. dec. 2, vol. iii. p. 876, " On the probable Conditions 

 under which the Palaeozoic Kocks were deposited over the Northern Hemisphere. ' 



