USGS Professional Paper 1697 - Alaska Resources Library

116 Metallogenesis and Tectonics of the Russian Far East, Alaska, and the Canadian Cordillera
Jurassic to Neocomian formations that overly various accreted
terranes of the Kolyma-Omolon superterrane (Nokleberg and
others, 1994c, 1997c). The Indigirka-Oloy is composed mainly
of sandstone, siltstone, shale, conglomerate, and volcanic rocks
of varying composition. The igneous rocks of the Indigirka-
Oloy assemblage include coeval plutonic rocks and mainly
shallow-marine, rarely nonmarine basalt, andesite, rhyolite, and
tuff with interlayered sandstone, conglomerate, siltstone, and
shale. The belt also contains small bodies of granite, granodiorite,
and monzogranite. The igneous rocks of the Indigirka-
Oloy sedimentary-volcanic assemblage are interpreted as part
of the Jurassic Uyandina island arc, which formed on margin of
the Kolyma-Omolon superterrane during final stages of migration
towards but before accretion of the northeastern North
Asian Craton (Nokleberg and others, 2000).
Map
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Cross section
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Yassachnaya River Metallogenic Belt of Pb-Zn
Skarn, Porphyry Cu, and Cu-Ag Vein Deposits
(Belt YS) Western Part of Russian Northeast
The Yasachnaya River metallogenic belt of Pb-Zn skarn,
porphyry Cu, and Cu-Ag vein deposits (fig. 48; tables 3, 4)
occurs in the Yasachnaya River Basin in the western part of
the Russian Northeast. The belt extends in two branches to
the northwest for nearly 500 km and is as much as 100 km
wide. The deposits are hosted in or near Late Jurassic granitic
and subvolcanic intrusive bodies that are associated with
the Uyandin-Yassachny volcanic-plutonic belt, part of the
Indigirka-Oloy overlap assemblage (unit io, fig. 48) (Nokleberg
and others, 1994c, 1997c). The significant Pb-Zn skarn
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a
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Shale and siliceous
shale
Rhyolite
Basalt and andesitebasalt
Felsic tuff
Intermediate and
mafic tuff
Andesite, andesitebasalt,
tuff,rhyolite
flows,basalt flows, and
tuffaceous sandstone
Subvolcanic and
extrusive rhyolite
Ore body
Thrust fault (a, plan view; b,
Cross section)
Fault, sense of displacement
unknown
Contact
Strike and dip of bedding
Dogdin Suite
(Late Jurassic)
Emtandjin Suite
(Late Jurassic)
Figure 51. Khotoidokh kuroko Pb-Zn massive sulfide deposit, Chersky-Argatass Ranges metallogenic belt, Russian Northeast. Schematic
geologic map and cross section. Adapted from Dylevsky, Zuyev, and Shpikerman (1996). See figure 48 and table 4 for location.