Upper Daly-Alaska; Hoosier; Bertha; Western Mine, Hyder Mining District, Prince of Wales-Hyder Census Area, Alaska, USAi

Regional Level Types
Upper Daly-Alaska; Hoosier; Bertha; Western Mine	Mine
Hyder Mining District	Mining District
Prince of Wales-Hyder Census Area	Census Area
Alaska	State
USA	Country

The first claims on this property were located in 1912 and 1913. Descriptions of the Daly-Alaska property in early reports (Chapin, 1916, p. 97; Westgate, 1922, p. 128, 131-133; Buddington, 1925, p. 74, 83-84; 1929, p. 43-44, 86-88; Buddington and Chapin, 1929, p. 318, 327, 357-358), which were summarized by Cobb (1978, p. 23-24), do not consistently distinguish between the upper and lower workings. Elliott and Koch (1981, locs. 65, 66), however, describe the upper and lower workings separately, and their descriptions are used in this report (also see lower Daly-Alaska mine, BC065). In early reports, the name New Alaska Mining Company apparently applied in general to the Daly-Alaska property.
Location: The upper Daly-Alaska mine is in Section 25 at an elevation of about 1250-1800 feet on Daly Creek (Elliott and Koch, 1981, p. 17, loc. 66). Also see lower Daly-Alaska mine (BC065), and Additional Comments field, below.
Geology: The country rocks in the area of this site are pelitic metasedimentary and subordinate andesitic (greenstone) metavolcanic strata of the Jurassic or older Mesozoic Hazelton Group; the Triassic Texas Creek Granodiorite, which intrudes the Hazelton; the Eocene Boundary Granodiorite, which intrudes the Hazelton and Texas Creek rocks; and still-younger Tertiary lamprophyre dikes, which cut all the other rocks (Smith, 1973, 1977; Koch, 1996). The deposit at the upper Daly-Alaska mine (Elliott and Koch, 1981, loc. 66) is in fractured zones in silicified greenstone, tuff, and quartz porphyry. The zones contain disseminated pyrite, calcite veinlets, quartz gash veinlets, and bands and patches of relatively massive sulfide minerals. Sphalerite, galena, and pyrite are reported, along with lesser amounts of tetrahedrite, chalcopyrite, pyrrhotite and arsenopyrite. Selected samples of the sulfides probably contain silver and some gold. Concentrated sulfide samples from a shear zone at the upper Daly-Alaska mine site yielded an Eocene lead-isotope age (Maas and others, 1995, p. 254, 259). The deposit, however, is similar in mineralogy, structural setting, and hostrock to isotopically dated Jurassic deposits nearby in the Hyder district (see, for example, BC065, 067). The lode thus may be polygenetic, originating as a 'disseminated' deposit during Jurassic (Hazelton) island-arc volcanism (Alldrick, 1993), and then partly remobilized into shear zones during emplacement of the Boundary Granodiorite.
Workings: Deposit was explored by open cuts and more than 100 feet of underground workings, mainly between about 1915 and 1925.
Age: Concentrated sulfide samples from a shear zone at the upper Daly-Alaska mine site yielded an Eocene lead-isotope age (Maas and others, 1995, p. 254, 259). The deposit, however, is similar in mineralogy, structural setting, and hostrock to isotopically dated Jurassic deposits nearby in the Hyder district (see, for example, BC065, 067). The lode thus may be polygenetic, originating as a 'disseminated' deposit during Jurassic (Hazelton) island-arc volcanism (Alldrick, 1993), and then partly remobilized or reconstituted into shear zones during emplacement of the Boundary Granodiorite.
Alteration: Mineralized greenstone country rock is silicified and partly replaced by calcite and disseminated pyrite.
Production: A little ore was probably mined, but there is no public record of the amount of production.

Commodities (Major) - Ag, Au, Cu, Pb, Zn
Development Status: Yes; small
Deposit Model: Polymetallic veins

Other Databases

Link to USGS - Alaska:	BC066

Other Regions, Features and Areas containing this locality

References