13 Guo. 5 Prace River Districr. J 13

The small thickness of the bed and the depth at which it occurs of course make its use quite
impossible, notwithstanding the favourable quality and relative quantity of oil indicated. It is,
however, a feature that may be found of use elsewhere in the region, as in the valley of the
Peace (within the Block), where drilling can be begun on a much lower horizon. But its chief
interest is in the fact that it establishes the existence of oil of high grade in the district and
so adds to the likelihood of finding it in useful form and quantity in places where physical
conditions are favourable.

Like the coal, the character of this tar-clay indicates that such conditions are more likely
to be found where there has been less compression or other metamorphism of the rocks; that is,
generally speaking, farther from the mountains, or at least beyond the influence of the forces
that produced them.

SUMMARY AND CONCLUSIONS. j
i

The area of British Columbia east of the Rocky Mountains is approximately 40,000 square
miles. Nearly one-third of this territory, or 12,000 square miles, is in the basin of the Peace
River. But of this some 5,000 square miles are in the Peace River Block, a tract of Federal
lands which occupies the eastern central part of the latter area. There remains therefore about
7,000 square miles of the Peace River District east of the mountains with which this investiga-
tion is concerned. Quite half of this area, however, lies north of the Block and is not yet
accessible for conclusive examination.

The geological field surveys made in 1919 and 1920 covered rather more than 1,000 square
miles, including practically all of the accessible territory between the foot of the mountains and
the Peace River Block. The locality then selected for drilling was chosen for a preliminary test
in the area thus surveyed, and especially of the section of about 400 square miles north of the
Peace. The drilling showed the structure of the locality chosen to be even more favourable
than it was previously known to be. It also proved the existence of oil of favourable quality—
paraffin series—in the district. But it gave no producing well; and, moreover, the mode of
occurrence of the oil and the character of the coal indicate that the territory may be too near
the mountains, or, more precisely, too far within the influence of the disturbances that caused
them, to be likely to yield an oil production. The common occurrence of small amounts of gas,
if at all significant, rather goes to confirm this view.

This feature, of course, applies to the area both north and south of the Peace; that is,
within similar relation to the mountains. But the area that is unfavourably affected by nearness
to the mountains need not be a belt of uniform width. It may vary in breadth according to the
intensity of the stresses developed in mountain-building at different places along a range.
Consequently conditions in other localities at equal distance from the mountains may be either
more or less fayourable than those found at Red River and Lynx Creek. But this can only be
proved by drilling.

In general embayments in the front of a range, or intervals where the mountains recede
from the plain, are likely to show less alteration of their rocks than other places along the range.
In this respect such a locality as Miller Creek (see Spieker’s map, 1920) seems to be a favourable
one. FEyen the bank of the Peace River just west of the Block or Portage Creek near Rocky
Mountain Portage are quite as favourably situated in regard to the mountains as any site west
of the area already drilled at Red River.

As to other parts of the territory west of the Block, it would be easily possible to drill on
either the First or the Second Lynx Creek 3 or 4 miles farther from the mountains. But what can
now be seen of the structure is not particularly favourable and suggests that the thickness of
the St. John formation there would be even greater than at hole No. 6.!. In view of the depth
of the St. John and of the results obtained at hole No. 3, it does not seem advisable to go farther
east on the Red River.

Any work farther to the west—that is, nearer the mountains—wwould, as stated above, be
better directed to the vicinity of the Peace River or southwards.

One promising structure found by Mr. Spieker in 1920 is the Boulder Creek dome near the
south-west corner of the Block. This is important as being the only place yet known where
horizon of the Bullhead-Triassic contact may be reached. But it is as yet difficult of access for
a drilling outfit and is near the mountains and also to the boundary of the Block.

The natural mode of investigation of the district would be by trial drilling on structures
exposed along the banks of the Peace, where drilling could begin 800 feet or more below prairie-