The Ketchikan-Hyder district includes the southern end of the Alaska panhandle, roughly the area between lat 54Â°20' and 57Â°00' N. and long 130Â°00' and 134Â°00' W.
Most of the early mining interest in Alaska was centered in Sitka and Juneau, and Ketchikan was neglected for many years. But in the late 1890's discoveries of gold and copper were made at Ketchikan, and this together with the news of the Klondike successes encouraged many people to prospect the new area (Brooks, 1902, p. 39). By 1900 there was feverish activity in the district with several mines open and many claims located. Gold was produced from auriferous veins and from copper ores.
At Hyder, near the Canadian border, lode deposits of gold were discovered in about 1901 but were neglected until 1909, when a short-lived boom occurred (Buddington, 1929, p. 2-3). In the 1920's there were several small discoveries near Hyder that caused some mild excitement.
Production of gold from the Ketchikan-Hyder district amounts to about 62,000 ounces, of which 35,000 ounces is byproduct gold from copper ores and 27,000 ounces is from lode mines. Data for 1938-46 are incomplete. The district was still active in 1959, though only small quantities of byproduct gold were produced.
The oldest rocks in the district are limestone and phyllite of Silurian or pre-Silurian age. These are overlain by limestone, slate, and schist of probable Middle Devonian age. In the central part of the district the Devonian rocks are overlain by argillite, limestone, and sandstone of the Ketchikan Series, partly of Paleozoic and Mesozoic age. Locally, Mesozoic conglomerates overlie the Devonian rocks. A broad belt of granite (or diorite), part of the Coast Range batholith, underlies the eastern part of the district (Brooks, 1902, p. 40-41), but the most widely distributed igneous rock is the Kasaan Greenstone, which is the oldest of the intrusive rocks. Warner, Goddard, and others (1961, p. 13) imply that the greenstone is of Mesozoic age, but older than Cretaceous. In general the metasedimen-tary rocks throughout the district occur in northwest-trending bands (Brooks, 1902, p. 51).
The geology of the Hyder area is summarized as follows from Buddington (1929, p. 13-42). The Hazelton Group, of probable Jurassic age, is composed of greenstone, tuff, breccia, graywacke, slate, argillite, quartzite, and some limestone, and it occurs as large disconnected patches in the east and west parts of the area. The beds are tightly folded and strike predominantly to the east. A granodiorite batholith, called the Texas Creek batholith, intruded the Hazelton Group, and the Hyder Quartz Monzonite and the Boundary Granodiorite intruded both the Hazelton Group and Texas Creek batholith. The intrusive rocks are of Jurassic or Cretaceous age and are genetically related to the Coast Range batholith.
The ore deposits are somewhat varied in this district; commercial amounts of silver, copper, iron, lead, and zinc are present in addition to gold. The ore deposits are of four general typesâ€”vein deposits, breccia veins, mineralized shear zones, and contact metasomatic deposits. The veins occur in the oldest rocks of the district. They range in width from a few inches to 10 feet or more and are made up of quartz, calcite, pyrite, chalcopyrite, galena, sphalerite, and gold (Wright and Wright, 1908, p. 80-81). Breccia veins, most abundant in the limestone and schist, consist for the most part of quartz-cemented country rock. Auriferous sulfides may be in limestone fragments or in the quartz (Wright and Wright, 1908, p. 81-82). The shear zone deposits range in width from 5 to 50 feet and follow the structure of the enclosing rockâ€”most commonly slate or greenstone. The dominant minerals are quartz and calcite in veinlets and chalcopyrite and pyrite disseminated throughout the rock. Gold occurs in the quartz-calcite veinlets (Wright and Wright, 1908, p. 82-83). The contact meta-morphic deposits are in limestones near their contacts with intrusives. These deposits consist of masses of chalcopyrite, pyrrhotite, pyrite, and magnetite in a gangue of garnet, epidote, calcite, quartz, amphibole, and wollastonite. Both copper and gold are produced from these deposits (Wright and Wright, 1908, p. 83-84). On the Kasaan Peninsula, contact metasomatic deposits of magnetite, pyrite, and chalcopyrite are found in association with tac-tite bodies in layers and lenses of metamorphosed sedimentary rocks in the Kasaan Greenstone (Warner and others, 1961, p. 30-52).
Worthy of special mention is the Salt Chuck mine on the Kasaan Peninsula. Originally located as a copper prospect in 1905, this deposit was later found to contain platinum minerals and gold and silver in recoverable amounts (Holt and others, 1948, p. 3). The ore bodies are masses of bornite and chalcopyrite that have replaced and filled fractures in a pyroxenite country rock (Mertie, 1921, p. 124-125). According to Holt, Shepard, Thorne, Tolonen, and Fosse (1948, p. 4), a total of 326,000 tons of ore with an average gold content of 0.036 ounces per ton was produced from the beginning of mining to the spring of 1941. This amounts to 11,736 ounces of gold.
Page 3 of 4