428 



SCIENCE. 



[Vol. XIII. No. 330 



graphic point of view, as forming a partially submerged lateral ex- 

 pansion of the Coast Ranges. The highest mountain of Vancou- 

 ver Island — Victoria Peak — reaches an elevation of 7,4^4 feet, 

 while there is a considerable mountainous area in the centre of the 

 island which surpasses 2,000 feet in average altitude. Several 

 summits in the Queen Charlotte Islands exceed 4,000 feet. 



The Vancouver Range, while still to a considerable extent formed 

 of crystalline rocks like those of the Coast Ranges, is principally 

 composed of stratified rocks of paleozoic and triassic age, and is 

 flanked in places, both on Vancouver and on Queen Charlotte 

 Islands, by cretaceous rocks, which are here important because of 

 their coal-bearing character. The areas underlain by these rocks 

 are in general comparatively low, and hilly rather than mountain- 

 ous ; while a large tract of level land, based upon the tertiary for- 

 mation, occurs in the north-east part of the Queen Charlotte 

 Islands. Gold-placers have been worked in several places on Van- 

 couver Island, but few ever attained much importance. Iron, cop- 

 per, and lead ores and gold-bearing quartz are also known to occur 

 in connection with this mountain-axis ; but up to the present time the 

 coal deposits have proved to be vastly its most important feature.^ 



The general correspondence of that portion of the Cordillera 

 belt included in British Columbia with that of the western portion 

 of the United States, in some parts of which mining operations of 

 the first importance have been in progress now for many years, has 

 already been alluded to. No feature of the geology of the conti- 

 nent is more remarkable than the general persistence of certain 

 zones of similar rocks in a direction coincident with that of the 

 Cordillera itself, — a circumstance in part due to the original simi- 

 larity in conditions of deposition of sediments, and in part to their 

 equal participation, at a later date, in changes produced by like 

 metamorphic agencies. The similarity thus observed, in a series 

 of geological zones parallel to the general direction of the Pacific 

 coast, is here more striking than the continuity of the constitu- 

 ent orographic uplifts of the mountain-belt, and contrasts very 

 markedly with the diversity of rock-formations found to occur 

 where this belt is crossed at right angles. While metalliferous 

 deposits individually are inconstant, and even the best defined lodes 

 can be followed, in the vast majority of cases, for but a moderate 

 distance, their character is found to depend fundamentally upon 

 that of the enclosing or adjacent rocks, in which, under the re- 

 quired local dynamic and other agencies, these deposits are found 

 to recur with nearly identical features. It is not intended here to 

 discuss the resemblances and differences of the various rock series 

 met with in the corresponding region in the Western States with 

 those of British Columbia ; but it may be mentioned that the met- 

 alliferous districts of the province may with advantage be com- 

 pared by the miner with those which have already been more fully 

 developed in each corresponding portion of the Cordillera region 

 to the south, and that from such rational comparisons useful indi- 

 cations may be derived in the present early stages of the develop- 

 ment of the mines of British Columbia. 



The Rocky Mountains proper, as previously defined, can scarcely 

 be traced southward, with identical characters, farther than the 

 main head waters of the Missouri, beyond which the eastern ranges 

 of the Cordillera become more lax and irregular. The Gold Range 

 may, however, be followed farther in a southerly direction, being 

 continued by the Cabinet, Cour D'Alaine, and Bitter Root Moun- 

 tains for about 300 miles. The Interior Plateau of British Colum- 

 bia represents the Great Basin of Utah and Nevada, and the Great 

 Plains of the Columbia, and combines to some extent the features 

 of both ; though differing markedly from the first in the fact that 

 it is not here self-contained as to its drainage, and from the second 

 in the diminished importance of its tertiary lava-flood. It has 

 already been stated that the Coast Ranges of British Columbia are 

 not continued to the south of the international boundary. They 

 resemble the Sierra Nevada more closely than they do the Cascade 



1 In connection with the foregoing outline of the ruling physical and geological fea- 

 tures of the province, it should be stated, that while these features are moderately 

 well known in the southern portion of the province, and as far northward as the 56th 

 degree of latitude, and while in connection with the Yukon expedition some accurate 

 information has been obtained for the extensive northern portion, there yet remains a 

 large region, chiefly included between the 56th and 58th parallels, which, though 

 touched upon here and there by the gold-miner, is yet almost unknown geographically 

 and geologically. 



Mountains of Washington Territory and Oregon, and hold a simi- 

 lar relation to the interior basin with that held by the Sierra. 

 While, however, the Sierra owes its elevation to a time immediately 

 antedating the cretaceous, the main uplift of the Coast Ranges of 

 British Columbia occurred at or after the close of that period. The 

 Vancouver Range, again, dating from the same period with the 

 last, is not traceable south of the Columbia River, beyond which, 

 in Oregon and California, the Pacific is bordered by a range of 

 coast-hills, which, from a geological point of view, are of very re- 

 cent origin. 



In California the principal auriferous territory coincides with the 

 run of a certain belt of slaty and schistose rocks, which occurs on 

 the western flank of the Sierra Nevada ; these rocks being referred, 

 by their contained fossils, to the triassic and cretaceous divisions 

 of the geological scale. In British Columbia, while rocks of trias- 

 sic age are largely developed, and in some cases with characters 

 identical with those of the Californian gold-bearing rocks, no such 

 persistent belt of these rocks is found in connection with the Coast 

 Ranges, where (from what has just been said of the resemblance of 

 the two mountain systems) it might, from analogy, have been 

 sought for. While local occurrences of rich gold-placers are 

 known, in association with slates probably of triassic age, on both 

 sides of the Coast Ranges, the main auriferous territory in the 

 province is found to align itself on the Gold Range; and the origi- 

 nal deposits of gold, from which the placers have been supplied, 

 are already known to exist in different series of rocks widely sepa- 

 rated in age, and ranging all the way from the triassic to the Cam- 

 brian. While, therefore, there is no single well-developed gold- 

 producing region, as in California, the area and mass of the rocks 

 throughout which deposits of gold may be hopefully looked for are 

 here greatly increased. The circumstances would also warrant the 

 belief that the mode of occurrence of gold in its original matrix 

 might differ from that found to the south, and in particular that 

 this might be more varied. So far as investigation has gone, such 

 a belief appears to be well grounded, and it would seem that to a 

 very considerable extent the natural laws of this mining-field must 

 be worked out independently. 



In correspondence with the absence of the tertiary coast-hills of 

 California, in which, under peculiar conditions of mineralization, 

 the cinnabar ores of that State are developed, it is observable that 

 in British Columbia no really important deposits of mercury have 

 yet been discovered. It is by no means improbable that mercury 

 ores may yet be developed in the province ; but, if so, it cannot be in 

 any continuation of the Californian cinnabar belt, and the condi- 

 tions of such deposits may be expected to prove unlike. 



Another and very important point of diversity is found as re- 

 spects the cretaceous rocks of the southern and northern coast 

 regions. In California and Oregon the mineral fuels which have 

 been found and worked are lignites of tertiary age and of an infe- 

 rior value. Similar fuels are known on the coast of British Colum- 

 bia : but the rocks of the cretaeeous here assume the role of a coal- 

 bearing series, and yield coals of excellent quality, which more than 

 hold their own in competition with all other fuels employed on the 

 Pacific. 



Still another noteworthy circumstance of difference, and one 

 which is applicable to practically the entire area of the province 

 when it is contrasted as a whole with the Pacific States, is that 

 which has been produced by the general spread and movement of 

 ice over this region during the glacial period. The changes thus 

 effected in the distribution of surface materials, and directions of 

 drainage, have most important bearings on the question of placer 

 mining. They have also encumbered the surface of considerable 

 tracts with "drift" deposits, which, while tending to produce a 

 more fertile soil, largely conceal the indications to which the pros- 

 pector generally trusts in more southern latitudes. At the same 

 time, a great part of the oxidized upper portions of metalliferous 

 veins, together with the atmospherically decayed country-rock as- 

 sociated with these, has been removed ; thus often obscuring the 

 outcrops of such veins, which would otherwise be well marked, 

 and in the treatment of certain classes of ores rendering it neces- 

 sary to begin work from the first with machinery and processes 

 which in some other regions are only required after considerable 

 depths have been attained. 



