=29=
river would be about 10 miles long.
Natural Gas

The similarity of the geological formations within the Foot-
hills and Plains to those in areas farther south suggests the occurrences
of natural gas and petroleum. Natural gas was found in the formations
of the Fort Nelson area in drilling a well for water at the Muskwa air-
field. The well is reported to have encountered a flow of 150,000
cubic feet of gas per day from sandy shale at a depth of 1,000 to 1,012
feet. The gas proved on test to be 98.4 per cent methane.

The presence of large volumes of gas in more definite structures
to the west seems most probable.

Petroleum

The possibility of finding petroleum in the area of reference
depends upon the presence of suitable formations. From a review of the
above descriptions, it is evident that the Mississippian formations in-
clude argillaceous and arenaceous limestones of a type commonly petrol-
iferous. Overlying chert beds of Pennsylvanian age are suitable as cover
rocks. The thick Triassic arenaceous limestones also suggest porosity |
and similarity to petroliferous beds drilled in the Guardian well near
Pouce Coupé. The Cretaceous beds show lignitic or coaly characters, and
promise more in gas than oil content. Gas is already known to be present,
but its high methane content gives small promise of association with
petroleum.

Some: structural features are worthy of note. For 50 miles west
of Fort Nelson the structure of the plains, judging: from: outcrops, is’.
nearly horizontals “Gentle: domes-might=be Ceberstiziee by the seismograph.-~
West of mile 51, southwesterly dips of 5 to 83 degrees extend to a syncline
at the base of Teepee Mountain. Teepee, Steamboat, and Table Mountains
exhibit northeasterly dips of about 10 degrees.- To the west outcrops are
lacking in the broad valley of Mill Creek and for 10 miles beyond. There
is & possibility that this valley may be anticlinal. High angles, crushing,
and faults occur between miles 85 and 87, but the main character is antbi-
elinal. Thus far Cretaceous measures are involved, but to the west Triassic
strate rise in a pronounced anticline. Its front is crushed against Lower
Cretaceous sandstones. The anticline takes the physiographic expression of
& semi-cylindrical hill extending southeasterly, hub axis parallel to the
mountain front. The width of the fold is about 1s miles and its western
flank consists of vertical beds. Strata farther west consist of orushed
argillites presumably of Mississippian age. At mile 91 vertical limestones
and sandstones of Mississippian age occur. These and other outcrops re-
present a highly disturbed zone of Mississippian and Pennsylvanian beds
that are succeeded westerly by a thick series of folded and crushed Triassic
formations. These continue westward to the front of the mountains, where a
high-angled fault separates Siluro-Devonian and Triassic strata.

From the standpoint of petroleum production, the more highly
disturbed structures have little promise. Thus the pronounced anticline
between miles 87 and 89 is faulted against Palaeozoic strata on the west,
and is also faulted on the east. Structures farther west are generally
badly crushed and faulted.

The structures east of the Triassic anticline (mile 87 and ecast-=
ward to mile 85) are also considerably faulted, and for some distance beyond
mile 85 no outcrops occur near the road. There is a possibility that the
crushed anticline in Lower Cretaceous sandstones between mile 87 and mile 85
may have merit. The pressure from the anticline on the west may have con-
centrated hydrocarbons in the beds immediately to the east, and in that case