Alaska Gold Rush History and Genealogy





Placer Deposit of Alaska GEOLOGICAL SURVEY BULLETIN 1374

The Willow Creek district is the area drairn eastern tributaries of the Susitna River below Sunshine, by n em tributaries of Cook Inlet and Knik Arm east of the Susitna River and by the Matanuska River.

Most of the placer gold from the district was recovered streams that drain areas containing once-productive lode mines. Considerably more than half of the placer gold probably came from operations on Grubstake Gulch and the part of Willow Creek immediately below the mouth of Grubstake Gulch (29) where claims were staked as early as 1897 and mining was still in progress in 1969. The gold in the gulch was derived from a ferous quartz veins in mica schist, one of which was worked successfully at the Thorpe lode mine, near the head of a fork of Grubstake Gulch (Berg and Cobb, 1967, p. 31, 34). In other streams in the same general area, placer gold derived from veins in a dioritic batholith was found but not mined. Jasper (1967a) in the course of a geochemical reconnaissance, collected mineral concentrates from this part of the Willow Creek district identified scheelite and chalcopyrite in several samples. On Alfred Creek (36), workable gold placers were discovered in 1911 and mined sporadically on a small scale for many years. A little platinum accompanies the gold. Minor producti of gold was reported from upper Mazuma Creek (35), a nearby stream that drains an area underlain only by volcanic rocks and Tertiary conglomerate. According to Martin and Mertie (1914, p. 279—280) and Grantz (1956), the gold in the area must have been reconcentrated from the conglomerate, which originaly covered a much greater area than the remnants preserved. Mendenhall (1900, p 321-322) noted that gold had been found on several south-flowing tributaries of the Matanuska River, but later reports did not describe successful mining on any of them.

US Geological Paper 610

The Willow Creek district, an area of about 50 square miles, is 23 miles by road northeast of Wasilla and 21 miles northwest of Palmer. Gold-bearing veins were discovered in this district in 1906, but lack of transportation facilities hindered their development and no production was recorded until 1909 (Ray, 1954, p. 35-36). After 1909 the district developed steadily and maintained substantial annual production until 1951, after which there was only sporadic small-scale activity. Total gold production through 1959 was 652,080 ounces; nearly all production was from lode mines. The geology and ore deposits of this district were described by Ray (1954, p. 10-54). The oldest rock is muscovite-quartz-plagioclase schist. Intruded into this is a mass of quartz diorite, the Talkeetna batholith, which underlies the major part of the district. Dikes of lamprophyre, diabase, aplite, and pegmatite cut the intrusive. The batholith is believed to be of late Mesozoic age. Sedimentary rocks, including conglomerate, arkose, shale, and sandstone of Tertiary ( ?) age, dip to the south, away from the quartz diorite body. Numerous faults cut the quartz diorite. Those with the larger displacements are postore in age, trend northwest, and dip northeast. Two types of veins are in the quartz diorite: (1) an older nonproductive group, containing assemblages of chalcopyrite-molybdenite, pyrite-stibnite, or low-grade gold--quartz, and (2) minable gold-bearing quartz bodies in shear zones that occur along the southern margin of the quartz diorite. Vei~ minerals, in addition to quartz and gold, are pyn~e, arsenopyrite, sphalerite, chalcopyrite, tetrahednte, nagyagite, altaite, coloradoite ( ?) , galena stibnite ( ?) , and sparse scheelite. Gold; occurs as irregular grains in and around nagyagite and as fracture fillings in pyrite, and locally occurs as blebs and stringers in quartz.


HomeGenealogy Photo CollectionsTowns & Gold CampsCreeksFraternal OrganizationsMaps NewspapersMining Districts
© 2006, 2007, 2008, 2009, 2010, 2011 Nugget Ranch LLC