USGS Professional Paper 1697 - Alaska Resources Library

Table 3—Continued
Metallogenic Belt Major Mineral Deposits Types.
Environment and
Tectonic Event and
(Abbreviation) (Signifi cant Mineral Deposits)
Host Unit
Comments
Kobuk (KB) Podiform Cr; serpentinite-hosted
Island arc.
Subduction-related intrusion of mafi c-ultramafi c plutons into basal part of
asbestos.
Thrust slices of mafi c-ultramafi c Koyukuk island arc.
(Iyikrok Mountain, Avan, Misheguk rocks, upper Angayucham Mafi c-ultramafi c rocks hosting deposits form upper, thrust-slice part of
Mountain, Siniktanneyak Mountain) terrane.
Angayucham subduction zone terrane.
Southwestern Alaska Zoned mafi c-ultramafi c PGE.
Island arc.
Subduction-related intrusion of mafi c-ultramafi c plutons into basal part of
(SWA)
(Kemuk Mountain, Red Mountain) Goodnews terrane.
Togiak island arc.
Mafi c-ultramafi c rocks hosting deposits occur in tectonically linked
Goodnews subduction zone terrane.
Yukon-River (YR) Podiform Cr.
Island arc.
Subduction-related intrusion of mafi c-ultramafi c plutons into basal part of
(Caribou Mountain, Lower Kanuti River, Thrust slices of mafi c-ultramafi c Koyukuk island arc.
Holonada)
rocks, upper Angayucham Mafi c-ultramafi c rocks hosting deposits form upper, thrust-slice part of
terrane.
Angayucham subduction zone terrane.
Metallogenic Belts Formed in Late Mesozoic Gravina Island Arc in Southern and Southeastern Alaska, and Canadian Cordillera
Eastern-Southern Porphyry Cu, porphyry Cu-Mo.
Island arc.
Subduction-related granitic plutonism that formed the Gravina island arc on
Alaska (ESA) (Pebble Copper, Orange Hill, Bond Gravina-Nutzotin-Gambier the Wrangellia superterrane.
Creek)
belt, Wrangellia sequence,
Wrangellia superterrane.
Belt continued into Early Cretaceous.
Klukwan-Duke (KL) Zoned mafi c-ultramafi c Ti-Cr-PGE. Island arc.
Subduction-related mafi c-ultramafi c plutonism associated with basal part of
(Union Bay, Klukwan, Haines)
Gravina-Nutzotin-Gambier Gravina island arc on the Wrangellia superterrane.
belt, Wrangellia sequence,
Wrangellia superterrane.
Belt continued into Early Cretaceous.
Metallogenic Belts Formed in Late Mesozoic Collision and Overthrusting in Eastern Alaska and Canadian Cordillera
Fortymile (FM) Serpentinite-Hosted Asbestos.
Collisional.
Regional metamorphism occurring during obduction and overthrusting
(Slate Creek, Clinton Creek)
Alteration of ultramafi c rock, of oceanic lithosphere of Seventymile terrane onto the North American
Seventymile terrane.
Craton Margin.
Cassiar (CS) Serpentine-hosted asbestos.
Collisional.
Regional metamorphism occurring during obduction and overthrusting of
Cassiar (McDame)
Alteration of ultramafi c rock, oceanic lithosphere of Slide Mountain onto the North American Craton
Slide Mountain terrane.
Margin.
Francois Lake (FL) Porphyry Mo.
Collisional.
Anatectic granitic plutonism associated with obduction of Stikinia-
(Endako)
Francois Lake plutonic suite. Quesnellia island arc and associated subduction zone complexes onto the
North American Craton Margin.
Cariboo (CB) Au quartz vein.
Collisional.
Regional metamorphism occurring during obduction and overthrusting of
(Cariboo Gold Quartz, Frasergold) Veins in Downey Creek
Kootenay, Stikinia-Quesnellia arc island and associated subduction zone
Formation of Kootenay terrane. complexes onto the North American Craton Margin. Belt continued into
Early Cretaceous.
Rossland (RL) Au-Ag polymetallic vein.
Collisional.
Anatectic granitic plutonism associated with obduction of Stikinia-
(Rossland, Sheep Creek, Ymir Erie Veins in Nelson plutonic suite. Quesnellia island arc and associated subduction zone complexes onto the
Creek).
North American Craton Margin.
Island Porphyry (IP)
Continuing Metallogenic Belt
Belt started in Early Jurassic and ceased in early Late Jurassic.
Appendix 355