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

EXPLANATION
Overlap assemblages
(Cretacecus and Cenozoic)
f m ~ e
Dominonity ocecrric fmks:
~ ~
CRATON AND CRATON MARGIN AG Angayucham; BA Baker:
No* knericsn Craton
Norlh Amencan Cram Margin
CRAT0hlAL TERRANES
BR Bridge River: CC Cache Creek:
CG Chugach; GD Goodnews:
SM Slide Mounta~n; SV Seventymile
Dominantly lu&idites:
K1 Kilbuck-ldm: HO Mmashee
OCEANIC PLATES AND RIDGES
JF Juan de Fuca; PAC Pacific:
PASSIVE CONTINENTAL-MARGIN TERRANES JFR Juan de Fuca oceanic ridge
M Arctic Alaska: CA Cassia:
DL Dillinger: MY Myst~c:
NX Nixon Fork: PC Porcupine;
WS Wkkersham: YO York
METAMORPHOSED COMINEHTAL4ARGIN TERRANES
CO ColdkmI: KO Kawenay:
Conlacl
Acl~ve subduclion zone
- Ac~N~ strike-slip fault
y-
am ,logenic belt
-
RB Ruby: SD Seward:
Yf Yukon-Tanana
ACCRETED TERRANES
Innar.
csw~,;
* QN Qmsfellii; ST Stikinia
Intermediate:
U) Cadwallader:CR Chiiliwadc River:
I2 kmx UT Metiww: W l Walbwa
CMW
AX Alexander: KY Koyukuk: NY Nyac:
PE Penln-: TG Togiak: WR WrangeIIia
1999). Metamorphism occurred at quartz-albite- epidote-biotite subfacies, and the age of metamorphism is probably he-Vendian
(Shpikerman, 1998). The sediment-hosted Cu deposits and host rocks are interpreted as forming in rift-related troughs in a
sublittoral and shelf area during the early history of the Prikolyma passive continental margin terrane, during Middle or Late
Proterozoic incipient rifling of the North Asian Craton Margin (Shpikerman, 1998). The ironstone deposits of the Oroek
metallogenic belt (Pobeda deposit and others) occur in the Vendian Syapyakane suite which ranges from 300 to 800 m thick and is
composed of mainly feldspathic-quartz sandstones with thin interbeds and lenses consisting of hematite (martite), magnetite,
titanic magnetite, ilmenite, rutile, and zircon (Shpikerman, 1998). The sandstones are typical occurrences of Vendian beach
placers and are similar to sandstones in the Middle Riphean Spiridonova Formation which occurs to the west, also in the
Prikolyma terrane. However, these formations are underlain by the Gorbunova Formation which contains beds of dolomite and
stratiform hematite-carbonate iron deposits. The Prikolyma terrane is interpreted as a rifled fragment of the North Asian Craton
Margin (Verkhoyansk fold belt, unit NSV; Nokleberg and others, 1994c, 1997c; Shpikerman, 1998).
Lantarsky-Dzhugdzhur Metallogenic Belt of
Anorthosite Apatite-Ti-Fe and
Gabbroic Ni-Cu (PGE) Deposits (Belt LD)
Central Part of Russian Far East)
The Lantarsky-Dzhugdzhur metallogenic belt of anorthosite apatite-Ti-Fe and gabbroic Cu-Ni-Co-PGE deposits is hosted
in the co-named igneous belt of layered gabbro and anorthosite complexes in one of a linear series of mafic plutons which crop out
along in the Stanovoy block along the southern flank of the North Asian Craton (fig. 2; tables 3,4) (Nokleberg and others, 1997b,
1998).. The belt occurs in the northern Khabarovsk Province in the central part of the Russian Far East and in southern Yakutia.
U-Pb and Sm-Nd isotopic ages for the host anorthosite intrusions range from 1.7 to 1.9 Ga (Sukhanov and others, 1989; Neimark
and others, 1992).
The Lantarsky-Dzhugdzhur igneous belt consists of five gabbroic Cu-Ni-Co-PGE deposits that are hosted in anorthosite
and gabbro bodies that occur along the 1,000 km-long Stanvoy suture (collisional) zone between the Archean Aldan shield of the
North Asian Craton to the North and the Proterozoic Stanovoy block to the south. The Archean rocks to the north consist of gneiss
and schist intruded by Paleozoic to Mesozoic granitic rock (Lennikov, 1979). The rocks south of the suture zone consist of