GOODNEWS BAY DISTRICT
The Goodnews Bay district, along the southwest coast of Alaska between lat 59°00' and 59°40' N. and long 160°40' and 162°00' W., includes the area drained by the Goodnews and Arolic Rivers.
Placer gold was discovered about 1900 by prospectors from Nome (Harrington, 1921, p. 220), and for a few years thereafter placers along the Arolic River were mined on a small scale, though it is not known how much gold was produced. Several sporadic influxes of prospectors in the early 1900's were short lived because no profitable deposits were found (Harrington, 1921, p. 221). By 1911, however, production was reported annually from this district, and until 1947 the placers continued to yield small amounts of gold. From 1947 through 1959 the district was dormant. Total recorded production from 1911 through 1959 is about 29,700 ounces, all from placers. Data for 1931-46 are incomplete, so that the total given here is a minimum, though the magnitude is probably of the right order. The placers of this district are of two types (Harrington, 1921, p. 222-225). One type occupies wide gravel-filled valleys and represents a reworking of earlier glaciofluviatile materials. The other type is found in narrow valleys and is derived from stream erosion of bedrock since glacial times. Nar¬row quartz veinlets in sedimentary rocks that were invaded by granitic rocks are believed to be the source of the gold in the placers. None of the auriferous veins have been of economic value (Harrington, 1921, p. 223-224).
McKINLEY DISTRICT
The McKinley district, in the eastern part of the Kuskokwim River valley, includes the placer caps of McGrath, Takotna, and Medfra and the lode deposits of the Nixon Fork country.
Placers along the Kuskokwim and its tributaries have been productive since 1908, although in recent years activity has diminished considerably. In the winter of 1919-20 production began from lode mines in the Nixon Fork area (Martin, 1922, p. 149). Production for the district from 1908 through 1959 was 40,600 ounces of lode gold and 13,900 ounces from placers, but data are incomplete for 1931-46.
In the Nixon Fork area, the oldest rocks are low-grade metamorphic rocks of pre-Ordovician age overlain by a 5,000- to 7,000-foot-thick limestone of Ordovician age and by a small patch of Permian sandstone, slate, and limestone (Brown, 1926, p. 101-127). Upper Cretaceous and Eocene (?) shale, sandstone, and graywacke cover large parts of the area and are overlain locally in the north by Tertiary andesite, basalt, and rhyolite lavas. Several small intrusive masses of diabase, quartz monzonite and granite, and porphyritic dikes and sills of variable composition cut the layered rocks.
The gold lodes in the Nixon Fork area are contact metamorphic deposits in limestone along its contact with a quartz monzonite intrusive. Native gold occurs in association with copper carbonates and sulfides in irregular masses and shoots (Brown, 1926, p. 128-134).
TULUKSAK-ANIAK DISTRICT
The Tuluksak-Aniak district comprises the drainage basins of the Tuluksak and Aniak Rivers between lat 60°30' and 61°30' N. and long 159°00' to 161°00' W.
After 1900, prospectors from Nome roamed throughout the lower Kuskokwim River valley and made placer discoveries along the Innoko and Holitna Rivers and finally, in 1907 or 1908, in the Bear Creek area of the Tuluksak watershed (Maddren, 1915, p. 299-300). About 2 years later gold was found in the gravels of the Aniak River. From 1909 through 1959 the district produced 230,555 ounces of gold; however, the data for 1931-46 are incomplete. The district was active in 1959.
Flood-plain and bench gravels have been productive. The gold probably has been derived from small quartz stringers in the country rock composed of sandstone, shale, agglomerate, and fine-grained tuffaceous rocks. A granitic stock cuts the sedimentary rocks and probably was responsible for the mineralization (Maddren, 1915, p. 327).
