The Unexploited West / A Compilation of all of the authentic information available at the present time as to the Natural Resources of the Unexploited Regions of Northern Canada

by Ernest J. Chambers

CHAPTER XVII.

THE MACKENZIE RIVER REGION.

Economic Minerals.

The Territory Has Never Been Thoroughly Examined for Minerals.—Tar Springs on the North Shore of Great Slave lake.—The Devonian Rocks Throughout Mackenzie valley are Nearly Everywhere More or Less Petroliferous.—Lignite Discovered in Many Places, Also Gypsum.—Large Deposits of Excellent Salt.—Indications of Gold and Copper.—Indians Report Finding Mica.

Ever since Sir Alexander Mackenzie first passed down the river which now bears his name on his famous voyage of discovery in 1789, and described the burning beds of coal and the salt springs along its banks, the district now under review in these pages has excited the interest of the geologist and the prospector, but on account of the remoteness of the country from civilized settlement and the difficulties of transport, very little, comparatively, is known of the actual extent of mineral wealth of this immense area of country. True, expert explorers like Sir John Franklin, Sir John Richardson, Mr. R. G. McConnell, Mr. William Ogilvie, and Doctor J. M. Bell have conducted scientific surveys along the chief waterways and over some routes overland, and their reports have been splendid and valuable, but from scantiness of their equipment and the omnipresent necessity to economize time, these surveys, from a geological point of view, can be considered only as reconnaissances.

Comparatively brief summaries of what some of these explorers and some others have written and said as to the mineralogy of Mackenzie valley below the 60th parallel of latitude, will suffice to give an idea of what we really know on the subject.

During his explorations about Great Slave lake in 1887, Mr. R. G. McConnell, of the Geological Survey, inspected the tar springs on the north shore. The springs are situated a couple of hundred yards from the shore, at the base of a low limestone cliff, which runs inland from the lake, and are three in number, each of them being surrounded with a small basin, three to four feet in diameter, filled with inspissated bitumen, while the soil and moss for some distance away is impregnated with the same material. A small quantity of pitch is annually taken from these springs and used for boat building purposes, while a much larger supply could be obtained if needed. A sulphur spring resembling those at Sulphur point on the south shore of the lake, but much more copious, issues from the foot of the cliff in close proximity to the bituminous springs, and feeds a considerable stream. The rock through which the petroleum ascends here is a heavily bedded greyish, rather coarsely crystalline cavernous dolomite, and is entirely unlike the bituminous beds south of the lake and down the Mackenzie, which in most cases consist of calcareous shales. The dolomite is everywhere permeated with bituminous matter, which collects in the numerous cavities, and oozing up through cracks, often forms small pools on the surface of the rock.

It was also reported to Mr. McConnell that sulphur and tar springs occur at a point half way between the springs he visited and Fort Rae. On the south shore bituminous shales and limestones outcrop at several points, and it would thus appear, according to Mr. McConnell, that the oil-bearing beds underlie the whole western part of the lake.

Promising Indications of Oil.

The Devonian rocks throughout Mackenzie valley, Mr. McConnell reports, are nearly everywhere more or less petroliferous, and over large areas afford promising indications of the presence of oil in workable quantities. He states that he noticed, in descending the Mackenzie, that bituminous limestones outcropped at the “Rock by the River Side”, at Bear Rock, at the Ramparts, and at numerous other places. Near Fort Good Hope several tar springs exist, and it is from these that the Hudson’s Bay Company now obtain their principal supply of pitch. The springs are situated at some distance from the river and were not examined. Still farther down, in the vicinity of the site of old Fort Good Hope, the river is bordered for several miles by evenly bedded dark shales of Devonian age which are completely saturated with oil. The possible oil country along Mackenzie valley, he concludes, is almost co-extensive with that of the valley itself. On the Mackenzie, the Tertiary beds at the mouth of Bear river hold several seams of lignite, ranging in thickness from two to four feet, and one seam which was concealed at the time of Mr. McConnell’s visit is reported by Richardson to be nine feet thick. The lignite there is of inferior quality, and has been burnt in many places for some distance from the surface by fires which have been in existence since the river was first discovered. Gypsum occurs in large quantities in the Devonian rocks of Bear mountain at the mouth of Bear river.