USGS Professional Paper 1697 - Alaska Resources Library

28 Metallogenesis and Tectonics of the Russian Far East, Alaska, and the Canadian Cordillera
a layer as much as 600 m thick that consists of alternating,
weakly metamorphosed Cambrian dark gray jasper, schist,
shale, spilite, basalt, and basaltic tuff that is interlayered
with rare sandstone, siltstone, sedimentary breccia, limestone,
and dolomite. The volcanogenic Mn deposits consist
of partly metamorphosed, steeply dipping, lenticular and
sheeted, bedded Mn bodies that occur in a diverse Lower
Cambrian sequence of jasper, shale, schist, spilite, basalt,
and basaltic tuff that overlays a carbonate reef complex with
seamounts. The Fe and Mn deposits occur in long beds and
lenses and are interpreted as forming during seafloor hydrothermal
activity and associated with basaltic volcanism that
was accompanied by chert deposition in seafloor depressions.
The sedimentary P deposits are hosted in complex,
steeply dipping and folded sequence of jasper and volcanic
rocks, which represent a reef edifice. The deposits consist of
carbonate beds that contain phosphorite-bearing breccia with
Cambrian fossils. The sedimentary breccia is interpreted as
forming in atoll fans and seamounts (Khanchuk, 1993).
The Galam terrane consists of a complexly built accretionary
prism with numerous regional-size olistoliths of early
Paleozoic (Cambrian and Ordovician) marine basalt, chert,
A
Map
400 m
0
A
B
and clastic rocks (Khanchuk, 1993). The matrix consists of
late Paleozoic turbidite and olistostrome. The early Paleozoic
strata and overlying middle to late Paleozoic sedimentary
rocks are interpreted as forming in a marine basin (Shkolnik,
1973; Khanchuk, 1993).
Omulevka River Metallogenic Belt of Austrian
Alps W and Kipushi Cu-Pb-Zn Deposits (Belt OR),
Northwest Part of Russian Northeast
The Omulevka River metallogenic belt of stratabound
Austrian Alps W and Kipushi Cu-Pb-Zn deposits (fig. 2; tables
3, 4) occurs in the northwest part of the Russian Northeast
(Shpikerman, 1998). The belt occurs between the Moma and
Omulevka Rivers, and is hosted in the northeastern part of the
Omulevka passive continental margin terrane of the Kolyma-
Omolon superterrane (Nokleberg and others, 1994c, 1997c).
The belt is greater than 300 km long and is as much as 100
km wide. The significant deposits are the Omulev stratabound
Austrian Alps W deposit and the Vesnovka Kipushi Cu-Pb-Zn
deposit (table 4) (Nokleberg and others 1997a,b, 1998).
Cross Section
0 400 800 m
B
400 m
0
Granodiorite
(Early Cretaceous)
Sedimentary rocks (Cambrian)
Sandstone
Interbedded
sandstone,
siltstone,
and chert
Chert
Ore body
Contact
metamorphic
(hornfels) zone
Contact
Figure 10. Gerbikanskoe volcanogenic Fe deposit, Galam metallogenic belt, Russian Southeast. Schematic geologic map and
cross section. Adapted from Shkolnik (1973). See figure 2 and table 4 for location.