228 PETROLEUM IN THE NORTH-WEST TERRITORIES. 
wyan is situated on Athabaska Lake where Slave River leaves it and 
Fort Resolution is built on the south shore of Slave Lake where the 
same river enters it. Sir John Richardson says that on this river, 
thirty miles from Fort Chipewyan, there is a limestone cliff “ the 
lower beds of which have a compact structure, a flat conchoidal 
fracture and a yellowish-grey color. Some of the upper beds contain 
mineral pitch in fissures ” and they also hold Devonian fossils., 
The western extremity of Slave Lake is about 115 miles west of 
Fort Resolution and here it discharges its waters by the McKenzie 
River. Numerous islands occur in this part of the lake, the largest 
of which is Big Island, so celebrated in the writings of northern 
travellers for its productive fishery. The next localities for petroleum 
which I shall notice are two of those about which I was informed by 
my friend Mr. Hardisty. One of them is situated about ten miles 
north-eastward of the Big Island Fishery. Here the oil rises from ; 
the bottom of the lake in about five feet of water, in a bay, and at 
a distance of a mile and a half from the shore. This bay is the one 
most nearly opposite to Big Island. The petroleum is of a dark 
color and in calm weather in summer it spreads itself over the sur- 
face of the lake, but in winter it keeps the water open directly over — 
the source from which it rises, forming a round hole in the ice, in 
which it accumulates to a sufficient depth to be easily dipped out. 
It has the ordinary smell of petroleum, is very liquid and when 
thrown upon a fire it explodes. In many places along this part of 
the north shore of the lake petroleum oozes out of the earth and its 
smell is quite noticeable to the traveller in passing by the coast. On 
the main shore of the next bay east of the one above referred to, there 
is a copious spring or puddle of tar and pitch mixed with leaves and 
sticks, which, if cleared out, would no doubt fill up with liquid oil. 
This spring was discovered by Mr. John Hope, of the Hudson Bay 
Company. The western part of Slave Lake is shallow and its bottom 
and shores are underlaid by bituminous limestone and dark, bitu- 
minous shales of Devonian age. Mr. Woodward in referring to some 
of the corals from these limestones mentions that their cysts are filled 
with bitumen. 
Perhaps the most remarkable locality for petroleum in the North- 
West Territories is one described to me by Mr. Hardisty as occurring 
about seventy miles eastward of Fort Simpson, which is situated on 
the McKenzie River at the junction of the Liard. This locality is 
