November i8, 1897 J 



NA TURE 



63 



to the shores of the open Atlantic, with still the same glacial 

 surroundings I 



In the early afternoon at Heron Bay, Lake Superior lay below 

 us, and until nightfall our course ran through the bold and pic- 

 turesque scenery of its cliffy margin. Old beach-terraces lying 

 high above the present lake were pointed out to us in many 

 places, these being the margins of different stages of the ancient 

 glacier-dammed lake of vast extent to which the names Warren, 

 Nipissing, &c., have been applied. 



Towards evening there came a change in the profile of the 

 land, striking alike to the geologists and the geographers, the 

 familiar low hummocky outlines of the Archcean giving place 

 to the bolder features of broad tabular rock-masses rising high 

 above the lake with cliff like sides, the bright red tints of 

 which were strongly accentuated by the setting sun. These 

 masses are composed of Lower Cambrian rocks (Animikie and 

 Keweenawan), chiefly red sandstones and shales with some 

 thin limestones, preserved under a capping of columnar diabase, 

 which rest with the most pronounced unconformability, cake- 

 like, upon the irregular Archjean floor, like the Torridon Sand- 

 stone on the gneiss in the North-west Highlands. 



As if the elements themselves were imbued with the spirit of 

 Canadian hospitality, not only was the weather almost through- 

 out our tour everything one could desire, but also on this 

 particular evening there came a fine display of aurora borealis to 

 charm us when darkness had hidden the land. 



The following day, August 30, we arrived early at Rat 

 Portage, the chief mining centre of Western Ontario, where 

 we found Mr. Mclnnes, of the Canadian Survey, just in from his 

 camp to meet us. Here again we were received by the prin- 

 cipal citizens, and led at once to the wharf on the beautiful Lake 

 of the Woods, where a special steamboat had been chartered for 

 us. The extremely interesting Archsean geology of this region 

 has been made known to European geologists by the classic 

 Canadian Survey Memoir of Prof A. C. Lawson, and we re- 

 joiced in the opportunity to examine some of the sections 

 described by him. Our first object was to visit the highly suc- 

 cessful Sultana gold mine on an eastern arm of the lake. On 

 the way thither we stopped to land at one of the Indian Reser- 

 vations, where a curious native burial-ground had attracted our 

 attention ; and the pathetic mementos which decorated a child's 

 grave excited our somewhat too obtrusive interest. Later in 

 the day we were enabled to visit a second camp, and see 

 something of its living inhabitants. 



At the Sultana Mine, where a mill of ten stamps is already at 

 work and a number of additional stamps are being erected, we 

 were shown the process of treating the ore, which is largely 

 free-milling, only 20 per cent, of the gold being left in the con- 

 centrates for recovery by the chlorination process. The metal 

 occurs in a quartz vein, at one place admirably exposed at the 

 surface, which traverses the country-rock near the contact of 

 granite, said to be Laurentian, with Huronian diabase. 

 Throughout the Dominion it appears to be in similar positions 

 around the contact of intrusive masses that the chief metal- 

 liferous deposits are found. 



Led by Prof. Coleman, to whom this whole region is familiar, 

 and by Mr. Mclnnes, we next ascended the hill to the east of 

 the mine, and further examined the junction of the so-called 

 Laurentian granite with the Huronian rocks, and noted the 

 intrusive character of the former. Then rejoining our steamer 

 we went westward to some islands in the lake, on which the 

 agglomeratic and apparently volcanic character of the Huronian 

 rocks was well displayed. 



The waters of the lake were thick with a minute green float- 

 ing organism, probably an alga. It is said that there are 13,000 

 islands in this lake alone ; which may be an over-estimate, but 

 they are certainly very numerous. We were told that they were 

 to be bought at all prices, from five dollars upwards, so that the 

 possession of a private island in this part of the world need not 

 be an expensive luxury. And it might, perchance, hold a gold- 

 mine I 



Spending the night at Rat Portage the geologists were early 

 astir next morning, and found time for further investigation of 

 this interesting locality. Under Prof Coleman's guidance we 

 studied the contact of Laurentian and Huronian at several points 

 to the westward of the town, near where the waters of the lake 

 pour through three distinct outlets to form the Winnipeg River. 

 It can scarcely be said that our investigations enabled us to 

 grasp the complex relationship of these great rock-groups, 

 though in some of the sections the gneissic Laurentian seemed 



NO. 1464, VOL. 57] 



clearly to be intrusive upon the Huronian. But the general 

 impression to be gathered from all we saw of these rocks was 

 that the term Huronian might include very different rocks in 

 different places, and that still more was this the case with the 

 term Laurentian. Until the Post-Archoean rocks are reached no 

 strict divisional lines seem possible. Upon such difficult 

 problems as these of the oldest rocks, however, the casual 

 observer of a few isolated sections has really no right to own 

 an opinion. 



The enormous water-power which the Lake of the Woods 

 contains, has to a slight extent already been utilised at one or 

 the other outlet, in the production of an electric supply for the 

 city, and for driving extensive flour-mills at Keewatin. But a 

 fine dam is now nearly finished by which the whole outflow will 

 be made available for industrial purposes, and it has even been 

 proposed to convey the power to Winnipeg over 100 miles distant. 

 The navigation of the lake between Rat Portage and Kee- 

 watin had lately been much impeded by a floating island of 

 vegetation, but this, as we saw, had been surrounded with a 

 boom of logs, and fixed to the shore. 



Boarding the train again at Keewatin, our course lay for a 

 few hours longer through typical Archaean country ; but gradually 

 the old rocks sank beneath the drift-plain, and before reaching 

 Winnipeg in the afternoon we had passed once more on to a 

 hidden platform of the Older Palaeozoics, and had reached the edge 

 of the great prairies. We were now within the basin of the 

 glacial Lake Agassiz. This extinct lake is believed by its ex- 

 plorer, Mr. Warren Upham, to have extended eastward well 

 beyond the Lake of the Woods, and westward to the ' ' second 

 prairie steppe" of Dr. Dawson, a breadth of about 250 miles, 

 while the length from its termination southward in Minnesota to 

 its northern shore against the ice-sheet north of the present Lake 

 Winnipeg may have been nearly 700 miles ; its area has been 

 given as about 1 10,000 square miles, or greater than the total of 

 the six existing great lakes, Superior, Michigan, Huron, Erie, 

 Ontario and Winnipeg ! It is to its finer sediments that the 

 wonderfully productive character of the soil of the Manitoba 

 prairies is largely due. 



At Winnipeg, the " half-way house " of the continent, the 

 westbound trains stop for an hour and a half to refit. With 

 special tram-cars at our service, we were thus able to see some- 

 thing of this substantial city with its many handsome buildings. 

 The old Hudson Bay post. Fort Garry, standing in their midst, 

 reminded us how marvellously rapid has been the growth of this 

 western capital. 



On the evening of August 31, with Winnipeg behind us, the 

 crossing of the plains had fairly commenced. Some writer — it 

 must surely be Lawrence Sterne — has pointed out the great value 

 of a plain to the discursive recorder of travels. One could not 

 do better than follow this preceptor by setting down here some 

 general reflections which might otherwise find no place for 

 themselves. 



First, we have to regret how few in number were the British 

 geologists to avail themselves of this magnificent opportunity for 

 study. It is often urged against us, and not without reason, that 

 we are too insular in our ideas and too apt to ignore the work 

 dqne beyond our borders. Certainly the geologist who confines 

 his attention solely to the neat details of British stratigraphy can 

 scarcely hope to realise the true proportions of the problems 

 with which the earth-student must deal. Explanations of 

 phenomena which seem quite applicable on the small scale, 

 often reveal their essential inadequacy under wider conditions 

 of application. And for a corrective study of broad conditions 

 this transcontinental journey must assuredly be unrivalled. 



The railway goes more or less at right angles to the strike 

 of the continent, and traverses therefore all the main rock- 

 masses of which the land is built, and all the great structural 

 features by which it is diversified. Hence the final impression 

 which the geologist receives is that of some vast diagrammatic 

 section of a continent. Even the scant time spent in making the 

 traverse was, on this occasion, compensated for by the presence 

 of the men who knew all that is yet known of the route, and 

 who were always ready to impart what they knew. 



Next, although in the abstract patriotism is out of place in 

 science, let us record the sense of gratification felt by the British 

 members of the party, that across the breadth of this wide and 

 prosperous Dominion we were among brothers. One could 

 scarcely make a journey of this kind without becoming a little 

 more Imperialist than before. 



Then let us set down our admiration for the work of the 



