32 PBOP. T, G. BONNEY OH THE HTJKOiNlAN SERIES 



5. Notes on a paet of the Httkonian" Series in the Keighbofehood 

 of SuDBTJEY (Cai^ada). By T. G. BomxET, D.Sc, LL.D., F.E.S., 

 Y.P.G.S., Professor of Geology in University College, London, 

 and Fellow of St. John's College, Cambridge. (Read N'ovem- 

 ber 9, 1887.) 



Dttring my visit to Canada in 1884, I had the opportunity, through 

 the liberality of the Directors of the Canada Pacific Railway, of 

 examining more minutely than is possible to the passing traveller 

 the geological structure of a part of the route over which the line 

 had recently been constructed. I had further the great advantage 

 of being accompanied by Dr. Selwyn, the Director General of the 

 Geological Survey of Canada, to whom I record my most grateful 

 thanks, not only for advice and guidance on the spot, but also for 

 information and specimens subsequently supplied. The study of 

 these has brought out some peculiarities which I think may help 

 to render more precise the term Huronian, and throw some light on 

 general questions of metamorphism *. 



On the Canada Pacific Railway, the Laurentian series, which has 

 been traversed for nearly 240 miles t, comes to an end near a little 

 station called Wahnepitae. The last rock seen is highly crystalline, 

 an eclogite or garnetiferous hornblendic gneiss, which apparently 

 dips at a rather low angle towards the S.E. Hard at hand is a 

 river, on the opposite side of which rises an ice-worn range of low 

 rocky hills considered to be the Huronian. The valley is believed 

 to follow the Hue of a fault. The latter rock is mainly composed of 

 quartz and felspar, with but little mica, though occasional thinnish 

 bands of a fissile mica-schist occur. It is much jointed, and appears 

 to have a flaggy bedding, reminding me in its general aspect of parts of 

 the Highland " eastern gneiss," in GlenDocherty (that is, where the 

 crushing is less conspicuous), or of the schistose series on the south 

 side of Porth Nobla, Anglesey. The dip of the apparent bedding is 

 rather more to the east and is slightly steeper than that of the 

 Laurentian ; but the difference both in direction and amount is not 



* In my Presidential Address to the Geological Society (Quart. Journ. G-eol. 

 Soc. Tol. xlii. Proc. p. 8i) I gave a very short account of this region ; but since 

 then I have studied more minutely all the specimens noticed, as well as a series 

 of slides cut from specimens sent to me by Dr. Selwyn i]i the spring of the present 

 year. A description of part of the region will be found in Sir W. Logan's 

 ' Geology of Canada,' pp. 50-52, 55. It is shown in the beautiful geological map 

 of Canada published by the Survey in 1886, and is noticed in a paper by 

 Mr. Irving in the fifth Annual Eeport of the Geological Survey of the United 

 States (1883-4). This general survey of the IS'orth-American Huronian rocks, 

 which embodies some most important observations by Professor Van Hise, 

 should be studied by everyone -who wishes to obtain a good idea of the Hm'onian 

 rocks. Our conclusions in many respects seem likely to agree ; but I may ven- 

 ture to say that my own were formed quite independently. His lucid statement 

 of the problem presented by the Huronian could not be surpassed. 



t This is roughly measured along the railway in a straight line, avoiding one 

 or two outlying patches of Lower Palseozoic strata ; the Laurentian zone is not 

 far ofi' 200 miles broad. There are, however, frequent patches of drift. 



