Metallogenesis and Tectonics of the Russian Far East, Alaska, and ...

Sheep Creek Au-Ag Polymetallic Vein District
The deposits in the Sheep Creek Au-Ag polymetallic vein district (Kootenay Belle and others) consist of an assemblage
of pyrite, sphalerite, galena, and chalcopyrite which occurs in quark veins within quartzite, argillite, and argillaceous quartzite of
the Nevada and Nugget members of the Early Cambrian Quartzite Range Formation of the North American Craton Margin
(Panteleyev, 199 1 ; Schroeter and Laoe, 1991). Estimated combined production and reserves are 1.8 million tonnes grading 15 g/t
Au and 6 g/t Ag. The veins are controlled by northeast-trending faults which are particularly productive where they cross the mutes
of two north-trending anticlines. Tbe deposits are interpreted as related to local dikes of the Middle Jmsic Nelson Plutonic Suite.
Ymir-Erie Creek Au-Ag Polymetallic Vein Deposit
The Ymir-Erie Creek (Yankee Gid) Au-Ag polymetallic vein deposits whjcb consist of pyrite, galena, +alerite and
native gold, in a gangue of quartz, calcite and aidcrik which occur along northeast-trending shear zones la folded
metasedimentary rocks of the Late Triassic Ymir end Early Jurassic Rossland ~OCIPS (Schroeter rrnd Lane, 1991). The veins occur
near contacts of metasedimentary rocks int~uded by @toid dikes of the Middle Jwic Nehn Plutonic Suite to which the
deposits may be related (Hoy and Andrew, 1988; Hoy and others, 1998).
Origin of and Tectonic Controls for
Rossland Metallogenic Belt
The Rossland metallogenic belt occurs ir the southem Canadian Cordillera, and, on the basis of spatial, structural, and
age data, is interpreted as forming during intrusion of dikes and plutons of the Middle and Late Jurassic N e b Plutonic Suite
(Parrish and others, 1988; Woodsworlh and others, 1991). The Nelson plutonic suite consists chiefly of granodiorite, quartz
monzonite, and local monzonite plutons whicb yield isotopic ages mainly of 155 to 170 Ma witb local crustal inheritance. On the
basis of structural and temporal relations, the Nelson Plutonic Suite is interpreted as forming immediately after a period of
regional thrusting associated with accretion and obduction of the Stikinia. Quesnellia, Cache Creek, and Slide Mountain terranes,
and obduction of the latter two terrmes over the Yukon-Tanma, Kootenay, and Cassiar terranes, and over the North American
Craton Margin (Monger and Noklcberg, 1996; Nokleberg and others, 2000). This major compressional omgenic event included
regional metamorphism, deformation, cruslal-fhickeoing, anatectic magmatism, and uplift in the core of flhe Canadian Cordillera
By the Late Jurassic (about 1 55 Ma), dtlritras from this emergent orogenic welt in the eastern Canadian Cordillera was shed
eastwards onto the North American Cmion Margin (Cant, 1989).
Early Cretaceous Metallogenic Belts
(144 to 120 Ma; Figures 61,62)
Overview
The major Early Cretaceous matallogeaic belts in the Russian Far East, Alaska, and the Canradian Cordillem are
summarized in table 3 Md portrayed on figures 61 end 62. The major belts are as follows. (I) In the south part of the Russian
Far East is the Samarke maogenic belt (SA) whicb con&s W and porphyry Cu-Mo deposits. Tbis belt is Interpreted es
forming during anatectic granitic plubnism occurring during subduction of Kula oceanic ride along tha h.aashm &ental
margin of the Russian Soutbeasl. (2) In the same region are Algama (AL) belt which COIL^^^ shtifiorm2r deposits, aad the
Kondyor (KO) belt which co:odaims zoned mafic-ulttdc Cr-PGE deposits. The latter belt is hosted in zoned maffc-ul-c
plutons intruding Stanovoy block of the North Asian Craton, and the former belt is interpreted as related alkali igneuus rock
associated with the zoned mafic-ultra& plutonz that intrude the Stenovoy bkk. These two bb are intetpreted as f o e
during plutonic ~ntrusion dabad to cmhenh~-mgin transform faults. (3) In the cmld part of the Russian Far East are the
Selemdzha-Kerbi (SK) and Stanovoy (ST) bel~, which contain Au-quartz vcin and anatectic granitic-magmatistwmlaW deposits
and are hosted in veins and piutons which intruded vmbus terranea and the Stanovoy block of the North Asian Cmtm. Tbe belts
are interpreted as formiilg during colUsion of the Bureya and Kbnka continental-margin arc superterranes with the North Asian
Craton and and closure of the Mongol-Okhotsk Oaern. (4) In the Russian Northeast are the AUakh-Yun (AY), Darpir (DP), Kular
(KU), Shamanikha (SH), Tornpan (TO), Verkboymk fVK), Yana-Kolyma (YA), and Yana-Polousnen (YP) belts which contain a
large suite of Au quartz vcin, and granitic-magmatism-related deposits. These belts are hasted in tbe Vtrkboyansk granite belt
which intrudes the Kolyma-Omolon supemme and the North Asian Craton Margin and are interpreted as forming tkuing
regional metamorphism and a n ~ granitic c phtonism associated witb accretion of KolynaaOmolon suptame onto the North
Asian Craton Margin. (5) In the Russian Northerrs4 continuing on from the Late Jurassic, were: (a) the Oloy (OL) beh, which
contains granitic-magmatismerelated dqmsits a d is hosted in the Oloy island arc; (kt) the TamvatneyMainire (TAM) beh, which
contains podifonn Cr deposits and is hosted m zoned mafic-ul~~c plutom; and (c) the Mainits (MA) belt which c w ~
kuroko massive sulfide &posits. In the C m h Cordillera, also continuing on from the Latu Jurassic, was the Cariboo (CB) belt
of Au quartz vein deposits. (6) Also in the Russian Northeast was the Left Omolon (LO) belt, which contains porphyry M&u,