The Kenai Peninsula
region is the Kenai Peninsula south of Turnagain Arm and
west of the divide between Cook Inlet and Prince William Sound.
West of a line extending from the head of Kachemak
Bay to Turnagain Arm near the mouth of the Chickaloon River, most
of this region
is considerably less than 1,000 feet above sea level, though rolling
hills and a few steep—sided ridges rise to elevations of
nearly 3,000 feet. The Kenai Mountains to the east are chaacterized
by high relief, and many of the summits are between 4,000 and
6,000
feet in altitude. Deep fords, many with glaciers at their heads,
embay the coastline. Remnants of Pleistocene ice that covered
the entire
peninsula and extended far into the sea are preserved as alpine
glaciers and as the Harding and Sargent Icefields. Proglacial
lakes occupied
much of the lowland during parts of Pleistocene time. Two large
lakes in the lowlands, Skilak and Tustuména, lie behind
recessional moraines, although the Kasilof River, which drains
Tustumena Lake,
has cut down to bedrock. The drainage of the northern part of the
lowland is still not fully integrated. The entire region is free
of
permafrost.
The Kenai Mountains, the highest parts of which are virtually unexplored,
are made up of limestone, chert, and tuff of Triassic age that
rest
on metamorphosed older volcanic and clastic rock~ and are overlain
by Jurassic volcanics and a thick sequence ol intensely deformed,
but only slightly metamorphosed, slate and graywacke, mainly of
Late Cretaceous age (Kelly, 1963, p. 280-284; Berg and Cobb, 1967,
p. 76).
These rocks were intruded by Tertiary (?) dikes, sills, and stocks
that range in composition from granite to peridotite (Berg and
Cobb,
1967, p. 76; Richter, 1970 p. B4—B5). The lowland and adjacent
parts of Cook Inlet are underlain by many thousands of feet of
poorly
consolidated mainly continental, rocks of Tertiary age that rest
on a basement of rocks similar to those exposed in the Kenai Mountains
(Mac. Neil and others, 1961; Kelly, 1963). The Tertiary rocks are
buried by Quaternary deposits except along sea cliffs around the
southern
part of the Kenai Lowland, in isolated inland exposures, anc in
a few small remnants resting on older rocks on the southeast shore
of
Kachemak Bay and at Port Graham.
Only gold, alloyed with silver, and chromite have been mined
from lodes in the Kenai Peninsula region, although copper, lead
zinc, molybdenum,
antimony, and nickel minerals have been found (Berg and Cobb, 1967,
p. 73—82, fig. 14; Richter, 1970). The chromite is in two
dunite and pyroxenite stocks in the southern part of the Homer
district.
Quartz veins, in graywacke and slat and in small quartz diorite
stocks and granite dikes carry gold and various sulfide minerals.
The lode
gold production of the region probably was about 19,000 ounces.
Placer gold was first discovered in Alaska on the Kenai Rivet in
1848 (between
loc 5 and 7) by P. P. Doroshin, a mining
engineer
employeed by the Russian-American Co. In 1850—51 he attempted
to mine gold on a stream that flows into Skilak Lake and on two
small
tributaries of the Kenai River between Skilak and Kenai Lakes but
failed to find enough to repay his effort (Moffit, 1906a, p. 8).
Later
placer mining was concentrated the parts of the Hope district where
lode deposits were extensively explored and mined. A few streams
and
beaches in other parts of the Kenai Peninsula region were worked
on a small sea. In the area around Nuka Bay, however, where there
are
many gold-bearing lodes, placer gold has not been found. As production
statistics have generally included the output of Crow Creek at
neighboring
streams in the Anchorage district in that credited to the Kenai
Peninsula region, accurate figures are not available The total
for the Kenai
Peninsula from about 1895, the first yet production was officially
reported, through 1960 was probably between 100 and 105 thousand
fine
ounces of gold and an unknown amount of alloyed silver. Small-scale
placer operations were reported in 1961 and 1962. |