U.S. DEPARTMENT OF THE INTERIOR



U.S. GEOLOGICAL SURVEY



PREPARED IN COLLABORATION WITH:

RUSSIAN ACADEMY OF SCIENCES

GEOLOGICAL COMMITTEE OF RUSSIA

ALASKA DIVISION OF GEOLOGICAL AND GEOPHYSICAL SURVEYS

GEOLOGICAL SURVEY OF CANADA



SIGNIFICANT METALLIFEROUS AND SELECTED NON-METALLIFEROUS

LODE DEPOSITS AND PLACER DISTRICTS FOR

THE RUSSIAN FAR EAST, ALASKA, AND THE CANADIAN CORDILLERA



By



Warren J. Nokleberg (1), Thomas K. Bundtzen (2), 

Kenneth M. Dawson (3), Roman A. Eremin (4),  

Nikolai A. Goryachev (4), Richard D. Koch (1), 

Vladimir V. Ratkin (5), Ilya S. Rozenblum (6), 

Vladimir I. Shpikerman (4), Yuri F. Frolov (7),  

Mary E. Gorodinsky (6), Vladimir D. Melnikov (8), 

Michael F. Diggles (1), Nikolai V. Ognyanov (5), 

Eugene D. Petrachenko (5), Rimma I. Petrachenko (5), 

Anany I. Pozdeev (7),  Katherina V. Ross (3), 

Douglas H. Wood (3), Donald Grybeck (9), 

Alexander I. Khanchuk (5), Lidiya I. Kovbas (5), 

Ivan Ya. Nekrasov (5), and Anatoly A. Sidorov (4)



1-U.S. Geological Survey, Menlo Park

2-Alaska Division of Geological and Geophysical Surveys,

        Fairbanks

3-Geological Survey of Canada, Vancouver

4-Russian Academy of Sciences, Magadan

5-Russian Academy of Sciences, Vladivostok

6-Geological Committee of Northeastern Russia, Magadan

7-Geological Committee of Kamchatka, Petropavlovsk-

        Kamchatsky

8-Geological Committee of Amur Region, Blagoveshchensk

9-U.S. Geological Survey, Anchorage





OPEN-FILE REPORT 96-513-B



1997



This report is preliminary and has not been reviewed for 

conformity with U.S. Geological Survey

editorial standards or with the North American Stratigraphic 

Code. Any use of trade, firm, or product names is for 

descriptive purposes only and does not imply endorsement by 

the U.S. Government.





INTRODUCTION



        This report is a written tabular compilation of the 

significant metalliferous and selected non-metalliferous 

lode deposits and placer districts of the Russian Far East, 

Alaska, and the Canadian Cordillera. The report provides 

detailed summaries of the important features of the 

significant lode deposits and placer districts along with a 

summary of mineral deposit models, and a bibliography of 

cited references. Data are provided herein for 1,079 

significant lode deposits and 158 significant placer 

districts of the region. The tabular data are provided in 

Table 1 for significant lode deposits, and in Table 2 for 

significant placer districts at the end of report. 

Alphabetical indices of the tabular data are provided after 

Tables 1 and 2.



        The Alaskan and Canadian mineral deposit data are derived 

from revisions of Dawson (1984), Nokleberg and others (1987, 

1993, 1994a, b), from new unpublished data of the authors, 

and from recent publications. The Russian Far East mineral 

deposit data represent new compilations by the Russian 

authors using cited references and unpublished data of the 

authors.



        This report is also published in a paper version 

(Open-File Report 96-513-A). This report is one of a series 

of studies on the mineral deposits, metallogenic belts, 

bedrock geology, and tectonics of the Russian Far East, 

Alaska, and the Canadian Cordillera. Published major 

companion studies are: (1) a report on the metallogenesis of 

mainland Alaska and the Russian Northeast (Nokleberg and 

others, 1993); and (2) a tectonostratigraphic terrane map of 

the Circum-North Pacific (Nokleberg and others, 1994c).



METALLOGENIC AND TECTONIC DEFINITIONS



        The following key definitions are provided.



Deposit. A general term for any lode or placer mineral 

occurrence, mineral deposit, prospect, and (or) mine.



Metallogenic belt. A geologic unit (area) that either 

contains or is favorable for a group of coeval and 

genetically-related, significant lode and placer deposit 

models.



Mine. A site where valuable minerals have been extracted.



Mineral deposit. A site where concentrations of potentially 

valuable minerals for which grade and tonnage estimates have 

been made.



Mineral occurrence. A site of potentially valuable minerals 

on which no visible exploration has occurred, or for which 

no grade and tonnage estimates have been made.



Overlap assemblage. A postaccretion unit of sedimentary or 

igneous rocks deposited on, or intruded into, two or more 

adjacent terranes (Jones and others, 1983; Howell and 

others, 1985; Nokleberg and others, 1994c). The sedimentary 

and volcanic parts either depositionally overlie, or are 

interpreted to have originally depositionally overlain, two 

or more adjacent terranes, or terranes and the craton 

margin. Overlapping plutonic rocks, which may be coeval and 

genetically related to overlap volcanic rocks, link or 

stitch together adjacent terranes, or a terrane and a craton 

margin.



Prospect. A site of potentially valuable minerals in which 

excavation has occurred.



Significant mineral deposit. A mine, mineral deposit, 

prospect, or occurrence that is judged as important for the 

metallogenesis of a geographic region.



Terrane. A fault-bounded geologic entity or fragment that is 

characterized by a distinctive geologic history that differs 

markedly from that of adjacent terranes (Jones and others, 

1983; Howell and others, 1985; Nokleberg and others, 1994c). 

Constitutes a physical entity, i.e., a stratigraphic 

succession bounded by faults, inferred faults, or an 

intensely-deformed structural complex bounded by faults. 

Some terranes may be displaced (faulted) facies of other 

terranes.



LODE AND PLACER MINERAL DEPOSIT MODELS



Classification of Mineral Deposits



        Metalliferous and selected non-metalliferous lode and 

placer deposits in this report are classified into various 

models or types described below. This classification of 

mineral deposits was derived mainly from the mineral deposit 

types of Eckstrand (1984), Cox and Singer (1986), Nokleberg 

and others (1987, 1993, 1994a, b), cited references for 

specific models, and unpublished data of the Russian 

authors. The lode deposit types are grouped according to 

host rock lithologies and (or) origin. Lode deposit types 

that share a common origin, such as contact metasomatic 

deposits, or porphyry deposits, are grouped together under a 

single heading.



        The mineral deposit types used in this report consist of 

both descriptive and genetic information that is 

systematically arranged to describe the essential properties 

of a class of mineral deposits. Some types are descriptive 

(empirical), in which instance the various attributes are 

recognized as essential, even though their relationships are 

unknown. An example of a descriptive mineral deposit type is 

the basaltic Cu type in which the empirical datum of a 

geologic association of Cu sulfides with relatively Cu-rich 

metabasalt or greenstone is the essential attribute. Other 

types are genetic (theoretical), in which case the 

attributes are related through some fundamental concept. An 

example is the W skarn deposit type in which case the 

genetic process of contact metasomatism is the essential 

attribute. For additional information on the methodology of 

mineral deposit types, the reader is referred to the 

discussions by Eckstrand (1984) and Cox and Singer (1986). 

For each deposit type, the principal references are listed 

in parentheses.



Deposits Related to Marine Felsic to Mafic Extrusive Rocks



Kuroko Zn-Pb-Cu massive sulfide (Ag, Au, Cd, Sn, Sb, Bi, 

barite) (D.A. Singer in Cox and Singer, 1986; Franklin, 

1993)

        This deposit type consists of volcanogenic massive to 

disseminated sulfides that occur in felsic to intermediate 

marine volcanic, pyroclastic, and bedded sedimentary rocks. 

The deposit minerals are mainly pyrite, chalcopyrite, 

sphalerite, and lesser galena, tetrahedrite, tennantite, and 

magnetite. Local alteration to zeolites, montmorillonite, 

silica, chlorite, and sericite may occur. The volcanic rocks 

are mainly rhyolite and dacite flows and tuff with 

subordinate basalt and andesite. Deposits commonly 

associated with subvolcanic intrusions that focus heat and 

provide energy for circulating hydrothermal fluids and 

leaching reactions. Strata above intrusions display 

extensive high-temperature alteration, including metal 

depletion, extreme alkali modification, and silicification. 

Deposits may be associated with major units of epiclastic 

breccia and with local growth faults, either rift or 

caldera-collapse faults. Alteration pipes may develop in 

portions of faults that immediately underlie the deposits. 

The depositional environment is mainly hot springs related 

to marine volcanism in island arcs or in extensional regimes 

behind island arcs.



Besshi Cu-Zn massive sulfide (Cu, Zn, Ag) (D.P. Cox in Cox 

and Singer, 1986; Slack, 1993)



        This deposit type consists of thin sheet-like bodies of 

massive to well-laminated pyrite, pyrrhotite, and 

chalcopyrite and sphalerite, and lesser sulfide minerals, 

within thinly laminated clastic sedimentary rocks, basalt, 

and mafic tuff. Lesser minerals are magnetite, galena, 

bornite, and tetrahedrite, with gangue quartz, carbonates, 

albite, white mica, and chlorite. The rock types are mainly 

marine clastic sedimentary rocks, basaltic and less commonly 

andesitic tuff and breccia, and local black shale and red 

chert. Wall rocks may include sericite- and chlorite-rich 

schist, coticule, tourmalinite, and albite that common form 

strata-bound lenses or envelopes around the massive sulfide 

deposit, or may extend as much as five to ten meters into 

the adjacent host rocks. Coticule, tourmalinite, and albite 

may occur as stratiform layers that may extend laterally 

hundreds of meters beyond the massive sulfide deposit. These 

wall rocks form by hydrothermal alteration and (or) chemical 

sedimentation coeval with deposition of massive sulfide. 

Alteration is sometimes difficult to recognize because of 

metamorphism. Deposits typically form stratiform lenses and 

sheetlike accumulations of semi-massive to massive sulfide. 

Footwall feeder zones may occur. The depositional 

environment is interpreted as submarine hot springs related 

to the deeper zones of submarine basaltic volcanism along 

spreading oceanic ridges, possibly in areas where a 

spreading oceanic ridge occurs near a continental margin 

that is supplying clastic detritus.



Cyprus Cu-Zn-Ag massive sulfide (Au, Pb, Cd, Sn) (D.A. 

Singer in Cox and Singer, 1986)



        This deposit type consists of massive sulfides in pillow 

basalt. The deposit minerals are mainly pyrite, 

chalcopyrite, sphalerite, and lesser marcasite and 

pyrrhotite. The sulfides occur in pillow basalt that is 

associated with tectonized dunite, harzburgite, gabbro, 

sheeted diabase dikes, and fine-grained sedimentary rocks, 

all part of an ophiolite assemblage. Beneath the massive 

sulfides is sometimes stockwork pyrite, pyrrhotite, minor 

chalcopyrite, and sphalerite. The sulfide minerals are 

sometimes brecciated and recemented. Alteration in the 

stringer zone consists of abundant quartz, chalcedony, 

chlorite, and lesser illite and calcite. Some deposits are 

overlain by Fe-rich and Mn-poor ochre. The depositional 

environment consists of submarine hot springs along an axial 

graben in oceanic or back-arc spreading ridges, or hot 

springs related to submarine volcanoes in seamounts.



Volcanogenic Mn (R.A. Koski in Cox and Singer, 1986)



        This deposit type consists of sheets and lenses of 

hausmannite-rhodochrosite, rhodochrosite, and oxidized 

braunite in intercalated shales, jasper, marine basalt 

flows, and mafic tuff. The host-volcanic rocks differ from 

normal tholeiite basalt in being relatively rich in 

potassium, sodium, and titanium. The deposits generally 

occur in sequences with abundant chert, rather than in 

sequences dominated by volcanic rocks. The deposits are 

often associated with volcanogenic Fe deposits, and 

sometimes contain complexly-oxidized ferromanganese 

minerals. The depositional environment is presumably related 

to hot springs associated with marine basaltic magmatism. No 

relation exists between zones of Mn-minerals and volcanic 

edifices.



Volcanogenic Fe (Shekhorkina, 1976)



        This deposit type consists of sheeted magnetite, and 

rarely magnetite-hematite or magnetite-hydroxide that occur 

in interlayered dark-gray jasper, shale, sandstone, and 

sedimentary breccia that contain subordinate subalkaline 

mafic extrusive rocks,. Associated minerals are pyrite, 

pyrrhotite, chalcopyrite, arsenopyrite, and other sulfide 

minerals. Quartz is the dominant gangue mineral, along with 

Fe-rich chlorite, calcite, and gypsum. The depositional 

environment is presumably related to hot springs associated 

with marine mafic volcanism.



Deposits Related to Subaerial Extrusive Rocks



Au-Ag epithermal vein (D.L. Mosier and others in Cox and 

Singer, 1986; Sillitoe, 1993a)



        This deposit type consists of quartz-adularia, and 

quartz-adularia-carbonate veins with a wide variety of 

minerals, including Au- and Ag-sulfosalts, pyrite, 

chalcopyrite, argentite, galena, sphalerite, cinnabar, and 

stibnite. Associated minerals include electrum, 

chalcopyrite, Cu- and Ag-sulfosalts, with lesser tellurides, 

bornite, barite, and fluorite. Alteration minerals include 

quartz, kaolinite, montmorillonite, illite, and zeolites. 

One class of epithermal vein deposits, such as those at 

Creede, Colorado and Dukat, Russian Northeast, has high 

concentrations of Pb, Zn, and Ag, sometimes high Cu and low 

Au; another class, such as those at Sado, Japan, has high 

Au, moderate to low Ag, sometimes high Cu, and generally low 

Pb and Zn concentrations. For both groups, the host volcanic 

rock composition ranges from subalkalic andesite to 

rhyolite. Some deposits are observed or inferred to overlie 

subvolcanic Cu-Au, Cu-Mo, or Sn magmatic-rock-related 

deposits. Deposits may be overlain by barren, acid-leached 

zones, or silicified horizons. The depositional environment 

is intermediate to felsic volcanic arcs and centers 

developed over miogeosynclinal rocks (Creede-type) or older 

volcanic and plutonic rocks (Sado-type).



Volcanic-hosted Hg (Plamennoe type) (Kuznetsov, 1974; 

Babkin, 1975)



        This deposit type consists of massive to disseminated, 

veinlet-disseminated and brecciated cinnabar occurring 

either in: (1) in bed-like, lens-like and irregular bodies 

mostly in felsic and to a lesser extent, in intermediate and 

mafic volcanic horizons; or (2) at the contacts of 

subvolcanic intrusive and volcanic rocks. In addition to 

cinnabar, the deposit minerals commonly include stibnite, 

pyrite, and marcasite, with subordinate or rare 

arsenopyrite, hematite, Pb-, Zn-, and Cu-sulfides, and 

tetrahedrite, schwatzite, Ag-sulfosalts, gold, realgar, and 

native mercury. The gangue minerals are mainly quartz, 

chalcedony, sericite, hydromica, kaolinite, dickite, 

alunite, carbonate, chlorite, and solid bitumen. Cinnabar 

and associated minerals commonly occur in multiple layers. 

Wallrocks may be propylitically altered to quartz, sericite, 

kaolinite, and epidote. Native mercury is deposited mainly 

during intense alteration, and, to a lesser extent, by 

filling of open fissures and voids. This deposit type may be 

a variety of the epithermal quartz-alunite Au deposit type 

of Berger (1986). The depositional environment is generally 

the tectonic boundaries of major volcanic depressions and 

calderas.



Hot spring Hg (J.J. Rytuba in Cox and Singer, 1986)



        This deposit type consists of cinnabar, antimony, pyrite, 

and minor marcasite and native mercury in veins and in 

disseminations in graywacke, shale, andesite and basalt 

flows, andesite tuff and tuff breccia, and diabase dikes. 

Various alteration minerals such as kaolinite, alunite, Fe 

oxides, and native sulfur occur above the paleo-groundwater 

table; pyrite, zeolites, potassium feldspar, chlorite, and 

quartz occur below the paleo-groundwater table. The tectonic 

setting is continental-margin rifting associated with small-

volume mafic to intermediate volcanism. The depositional 

environment is fault and fracture systems near paleo ground-

water table in areas of former hot springs.



Silica-carbonate Hg (Kuznetsov, 1974; Voevodin and others 

1979; J.J. Rytuba in Cox and Singer 1986)



        This deposit type consists of cinnabar and associated 

minerals at the contact between serpentinite and graywacke. 

The Russian equivalent for this deposit type is listwandite. 

The deposit minerals are mainly common Hg-minerals, 

including cinnabar, and native mercury, along with stibnite, 

pyrite, realgar, orpiment, native arsenic, sometimes Ni-and 

Co-minerals, and sometimes W-minerals, including 

tungstenite, scheelite, and wolframite. Gangue minerals are 

mainly dolomite, breunnerite and ankerite in association 

with quartz, opal, chalcedony, calcite, dickite, and talc. 

Massive, veinlet, and disseminated minerals commonly occur 

in irregular lens-like bodies and veins in crush belts and 

mylonite zones, and in adjacent sedimentary rocks. Cinnabar 

mineralization is closely associated with silica-carbonate 

and argillic alteration. The depositional environment 

consists of zones of normal faults, perhaps superposed on 

older thrusts, that contain lenses of serpentinite, 

ultramafic rocks, and graywacke.



Volcanic-hosted Sb (Au, Ag, As) vein (Berger, 1978)



        This deposit type consists of veins, stockwork, and 

irregular mineralized zones that occur in felsic to 

intermediate volcanic sequences, intercalated volcaniclastic 

sedimentary rocks, flows, hypabyssal dikes and sills, and 

shallow parts of fractured granitic intrusions. The 

principal deposit mineral is stibnite with accessory 

arsenopyrite, pyrite, marcasite, berthierite, chalcopyrite, 

sphalerite, galena, native silver, native gold, native 

arsenic, cinnabar, realgar, orpiment, jamesonite, 

tetrahedrite-tennantite, Ag-sulfosalts, carbonate minerals, 

barite, fluorite, sericite, adularia, and clay minerals. 

Gangue minerals are mainly chalcedony, quartz and opal. 

Argillic hydrothermal alteration is common; other 

alterations may include carbonate minerals, pyrite, and 

zeolites. Associated volcanic rocks are generally of highly 

differentiated calc-alkalic composition. Mineralization 

commonly occurs on the flanks of subaerial volcanoes. 

Deposit type often occurs at the periphery of volcanic 

structures that host associated gold-silver, disseminated 

gold-sulfide, and mercury deposits. The depositional 

environment is subaerial, calc-alkaline volcanic flows and 

shallow intrusions.



Rhyolite-hosted Sn (B.L Reed and others in Cox and Singer, 

1986)



        This deposit type consists of cassiterite and wood tin 

that occur in discontinuous veinlets and stockworks, and in 

disseminations in rhyolite-flow dome complexes. Accessory 

minerals include topaz, fluorite, bixbyite, pseudobrookite, 

and beryl. Besides cassiterite and wood tin, the deposit 

minerals also include hematite, cristobalite, fluorite, 

tridymite, opal, chalcedony, adularia and zeolites. The 

associated wall-rock alteration minerals are generally 

cristobalite, fluorite, smectite, kaolinite and alunite. The 

host rhyolites commonly contain more than 75 percent silica 

and are enriched with potassium. Mineralization is 

controlled by fractured and brecciated zones occurring in 

the most permeable upper portions of flow-dome complexes. 

The depositional environment is regions of felsic volcanism 

erupted onto continental crust.



Sulfur-sulfide (S, FeS2 ) (Vlasov, 1976)



        This deposit type consists of three subtypes: (1) 

surficial sulfur deposited from gases and solutions; (2) 

lacustrine deposits formed in volcanic craters; and (3) most 

valuable economically, replacement deposits formed as 

metasomatic sheets and as irregular bodies in porous and 

fractured rocks. All three subtypes are genetically and 

spatially associated with andesite. The deposit minerals are 

generally diverse and consist mainly of sulfur and pyrite 

with lesser variable realgar, orpiment, metacinnabar, 

stibnite, sphalerite, and molybdenite. Sulfide content 

increases with the depth grading into massive sulfides. Host 

rocks are generally hydrothermally altered.



Stratiform Deposits in Fine-Grained Clastic and Siliceous 

Sedimentary Rocks



Sedimentary exhalative (SEDEX) Zn-Pb-Ag (J.A. Briskey in Cox 

and Singer, 1986; Goodfellow and others, 1993)



        This deposit type consists of stratiform, massive to 

disseminated sulfides and barite occurring in sheet-like or 

lens-like tabular bodies that are interbedded with euxinic 

marine sedimentary rocks including dark shale, siltstone, 

chert, and sandstone. Many deposits form in half-graben 

basins, are asymmetrical zoned, and range in form from 

mound-shaped vent complexes to flanking, interbedded 

hydrothermal, biogenic, and epiclastic sedimentary 

accumulations. Generally occur in basinal sediments that cap 

thick, continental syn-rift sequences of coarse-grained 

clastic rocks. Sometimes close temporal and in many cases, 

spatial association with alkaline and tholeiitic basaltic 

rocks, dikes, and sills that indicate associated 

hydrothermal activity is related to high-level magmas. The 

deposit minerals include pyrite, pyrrhotite, sphalerite, 

galena, and barite, and rare celesite and chalcopyrite. 

Extensive hydrothermal alteration may occur near vents, 

including stockwork and disseminated sulfides, silica, 

albite, and chlorite. The depositional environment consists 

of marine epicratonal embayments and intracratonic basins 

with smaller local restricted basins.



Bedded barite (G.J. Orris in Cox and Singer, 1986)



        This deposit type consists of stratiform, massive, and 

nodular barite interbedded with marine cherty and calcareous 

sedimentary rocks, mainly dark chert, shale, mudstone, and 

dolomite. The deposit type is often associated with 

sedimentary exhalative Zn-Pb or kuroko massive sulfide 

deposits (both described above). Alteration consists of 

secondary barite veining and local, weak to moderate 

sericite replacement. Associated minerals include minor 

witherite, pyrite, galena, and sphalerite. Also associated 

are phosphate nodules. The depositional environment consists 

of epicratonal marine basins or embayments, often with 

smaller local restricted basins.



Stratabound deposits in Coarse Clastic sedimentary Rocks and 

Subaerial Basalts



Sediment-hosted Cu (Kupferschiefer and Redbed) (Bogdanov and 

others, 1973; Eckstrand, 1984; D.P. Cox in Cox and Singer, 

1986)



        This deposit type consists of disseminated to less 

prevalent veinlet sulfide ores that occur in lens-like and 

layered bodies in red clastic sedimentary rocks, including 

shale, siltstone, and sandstone, that are often intercalated 

with basalts. The main deposit minerals are bornite, 

chalcocite, hematite, with rare chalcopyrite as large 

crystals, metasomatic veinlets, and clastic grains. Wall-

rock alteration consists of disappearance of red color of 

host rocks, and occurrence of quartz-carbonate-sulfide 

veinlets. The latter are sometimes abundantly associated 

with low-grade contact or greenschist facies regional 

metamorphism. Weathering results in development of green 

sinter and malachite and azurite crusts. The depositional 

environment is epicontinental, shallow marine basins that 

occur on passive continental margin shelfs, or adjacent to 

volcanic island arcs. This deposit type is commonly 

associated with Cu-bearing, island arc trachybasalts 

(shoshonites) formed at or near rift zones.



Basaltic Cu (Dzhalkan type) (Eckstrand, 1984; Kutyrev, 1984; 

D.P. Cox in Cox and Singer, 1986)



        This deposit type consists of stratabound disseminated Cu 

minerals in basalt lavas erupted into shallow coastal marine 

basins, and more seldomly onto the subaerial parts of 

oceanic volcanic islands. The volcanic rocks are generally 

interbedded with red sandstone, conglomerate and siltstone. 

The basalts lavas are generally potassic or alkalic and may 

include shoshonites and trachybasalts. Major deposit 

minerals are bornite, chalcopyrite, chalcocite, pyrite and 

native copper. These minerals occur both in the matrix of, 

and as amygdules in the porous roofs of basalt flows, and in 

veinlets within the basalts. The wallrocks are altered 

mainly to epidote, calcite, chlorite and zeolites. The 

deposit type is often associated with sediment-hosted Cu 

deposit type (Kupferschiefer and Redbed, described above). 

The depositional environment is epicontinental, shallow 

marine basins that occur on passive or rifted continental 

margin shelfs, or adjacent to oceanic volcanic islands. The 

depositional environment includes porous roof of basalt 

flows and synvolcanic fissures.



Clastic sediment-hosted Hg (Nikitovka type) (Kuznetsov, 

1974; Babkin, 1975)



        This deposit type consists of cinnabar and associated 

minerals that occur in lenses, stockworks, and other 

structures in flysch sequences composed of siltstone, shale, 

and conglomerate. Ore bodies include stockworks, lenses, 

bed-like and irregular bodies, and simple and complex veins 

in fault zones. Mineralization is controlled by sets of 

fractures, and by feathering major faults in anticlinal 

structures and dome-like uplifts. The deposit type usually 

contains several ore horizons. Deposit minerals are mainly 

cinnabar with subordinate stibnite, realgar, orpiment, 

various other sulfide minerals and sulfosalts, and native 

arsenic and native mercury. Gangue minerals are mainly 

quartz, chalcedony quartz, carbonate minerals, and dickite. 

Wall rocks may be altered to quartz, argillite, and 

carbonate minerals. Associated igneous rocks are mainly 

felsic and intermediate dikes. Mineralization is interpreted 

to have formed from low-temperature hydrothermal fluids that 

were related to either deep magmatic chambers or to low-

grade regional metamorphism. In many parts of Russia, 

clastic sediment-hosted Hg deposits commonly occur in rift 

environments in cratonal areas. However, in the Russian Far 

East, this model is also applied to Hg deposits that occur 

in clastic sedimentary rocks that are part of volcanic arc 

sequences.



Sandstone-hosted U (C.E. Turner-Peterson and C.A. Hodges in 

Cox and Singer, 1986)



        This deposit type consists of concentrations of uranium 

oxides and related minerals in localized, reduced 

environments in medium- to coarse-grained feldspathic or 

tuffaceous sandstone, arkose, mudstone, and conglomerate. 

The depositional environment is continental basin margins, 

fluvial channels, fluvial fans, or stable coastal plain, 

sometimes with nearby felsic plutons or felsic volcanic 

rocks. The deposit minerals include pitchblende, coffinite, 

carnotite, and pyrite.



Deposits in Carbonate and Chemical-Sedimentary Rocks



Kipushi Cu-Pb-Zn (D.P. Cox and L.R.. Bernstein in Cox and 

Singer, 1986)



        This deposit type consists of stratabound, massive 

sulfides hosted mainly in dolomitic breccia. Generally no 

rocks of unequivocal igneous origin are related to the 

deposit. The deposit minerals include pyrite, bornite, 

chalcocite, chalcopyrite, carrollite, sphalerite, and 

tennantite with minor reinerite and germanite. Local 

alteration to dolomite, siderite, and silica may occur. The 

depositional environment consists mainly of high fluid flow 

along faults or karst(?)-breccia zones.



Southeast Missouri Pb-Zn (J.A. Briskey in Cox and Singer, 

1986; Leach and Sangster, 1993)



        This deposit type consists of stratabound, carbonate-

hosted deposits of Pb-, Zn-, and Cu-sulfide minerals in 

rocks having primary and secondary porosity, commonly 

related to reefs on paleotopographic highs. This deposit 

type is also referred to as the Mississippi Valley type. The 

deposits are hosted mainly in dolomite, but are locally 

hosted in sandstone, conglomerate, and calcareous shale. The 

deposit minerals are mainly galena, sphalerite, 

chalcopyrite, pyrite, and marcasite, with minor siegenite, 

bornite, tennantite, barite, bravoite, digenite, covellite, 

arsenopyrite and other associated sulfide minerals. 

Alteration consists of regional dolomitization, extensive 

carbonate dissolution, and development of residual shale. 

The deposit minerals occur at interfaces between gray and 

tan dolomite, and also in traps at interfaces between 

permeable and impermeable units. Deposits do not normally 

display internal mineralogical or chemical zoning. The 

deposits commonly occur at the margins of clastic basins, 

generally in undeformed orogenic foreland carbonate 

platforms. Some occur in carbonate sequences in foreland 

thrust belts bordering foredeeps. Fewer are associated with 

rift zones. The depositional environment is areas of 

shallow-water marine carbonates, with prominent facies 

control by reefs growing on the flanks of paleotopographic 

basement highs.



Korean Pb-Zn massive sulfide (V.V. Ratkin, this study)



        This deposit type consists of Pb- and Zn-sulfide minerals 

in carbonate rocks. The host rocks are mainly limestone, 

dolomite, and lesser marl. The deposit minerals are mainly 

pyrite, galena, sphalerite, fluorite, and magnetite. The 

deposit minerals occur mainly as lenses and beds conformable 

to bedding in host rocks. Magnetite also forms layers that 

are interbedded with sulfide minerals, fluorite, and 

carbonate minerals. Little to no hydrothermal alteration 

occurs; mainly diagenetic alteration occurs in carbonates 

and associated rocks. The deposit type is intermediate 

between the sedimentary exhalative Pb-Zn and Southeast 

Missouri Pb-Zn deposit types. Examples in the Russian 

Southeast are the Voznesenskoe and Chernyshevskoe mines. The 

depositional environment is typically Late Proterozoic to 

Early Paleozoic carbonate-rich sedimentary rocks in basins 

that overlap folded metamorphic complexes of the Sino-Korean 

shield.



Ironstone (Superior Fe) (Kosygin and Kulish, 1984;

R.A. Eremin and V.I. Shpikerman, this study; W.F. Cannon in 

Cox and Singer, 1986)



        Chemical-sedimentary subtype (Kosygin and Kulish, 1984). 

This subtype consists of sheet-like horizons of magnetite 

and hematite-magnetite in clastic carbonate rocks that are 

associated with chert, quartz-sericite-chlorite schist, and 

dolomite. The deposits occur in early Paleozoic sedimentary 

rocks formed in basins overlying Precambrian granitic and 

metamorphic complexes. This subtype is a Paleozoic analog of 

itabirites.



        Prikolyma subtype (R.A. Eremin and V.I. Shpikerman, this 

study). This subtype consists of Fe and Ti minerals that 

occur in bed-like and lens-like bodies in sandstone grit and 

conglomerate. The deposit minerals are mainly clastic 

hematite, magnetite, ilmenite, and zircon grains that form 

concentrations that range up to 50 to 60 percent of the 

hosting clastic quartz, and feldspar-quartz sandstone beds. 

Bedded clastic rocks exhibit parallel-, cross-, and wavy-

bedding. Ferruginous sandstones are sometimes interlayered 

with carbonate rocks, which sometimes form rich iron 

deposits. Conformable and crossing bodies of massive and 

brecciated hematite ores also occur in regional 

metamorphosed carbonate rocks. The deposit type is 

interpreted as ancient lithified sea beach placers that are 

often highly metamorphosed and deformed.



Stratabound W (Austrian Alps-type) (Denisenko and others, 

1986; Rundquist and Denisenko, 1986; V.I. Shpikerman, this 

study)



        This deposit type consists of stratabound, thin veinlet, 

and disseminated scheelite ores that occur in bedded 

carbonaceous calcareous siltstone and argillite, commonly 

metamorphosed to phyllite and greenschist. Igneous rocks are 

generally lacking, except for scarce metamorphosed basalt 

sills. The deposit minerals are mainly scheelite, pyrite, 

with lesser realgar, galena and chalcopyrite. The deposit 

minerals are concentrated in carbonaceous calcareous 

siltstone beds surrounded by shale or mudstone beds. The 

deposit minerals may also occur along minor crossing faults, 

and in associated calcite and quartz veinlets. W is 

geochemically associated with Sb, Hg, and As. The deposit 

type is interpreted as forming during metamorphism of 

carbonaceous sedimentary rocks initially enriched with W.



Carbonate-hosted Hg (Khaidarkan type) (Babkin, 1975; 

Fedorchuk, 1983)



        This deposit type consists mainly of cinnabar in veinlets 

and in disseminations that occur in stratabound bodies in 

dolomite breccia and to a lesser extent in limestone 

breccia. The host rocks are reef and shelf limestones that 

formed in carbonate reefs and shelf areas of passive 

continental margins. The host rocks are subsequently altered 

to dolomite and brecciated during diagenesis and karst-

formation. Mineralization is confined to deep fault zones 

and is localized under impermeable clay layers. Magmatic 

rocks are rare diabase sills. The deposit minerals are 

cinnabar and lesser pyrite, sphalerite, stibnite, and 

anthraxolite, and rare galena and fluorite. Wall-rock 

alteration consists of jasperoid, and quartz and calcite 

veinlets. The depositional environment is artesian thermal 

water with possible deep sources of Hg.



Stratiform Zr (Algama Type) (Zalishchak and others, 1991; 

Bagdasarov and others, 1990; Nekrasov and Korzhinskaya, 

1991)



        This deposit type consists of hydrozircon and baddeleyite 

in lenses and veins that occur mainly in a layer of 

cavernous dolomite marble that ranges up to about 40 m 

thick. The ore occurs as breccia composed of fragments of 

metamorphic quartz and dolomite cemented by an aggregate of 

hydrozircon and baddeleyite. Baddeleyite also occurs as 

loose aggregates formed by weathering of primary ore. Some 

caverns in the dolomite contain colloform, sinter-type 

aggregates of hydrozircon and baddeleyite, but breccia ores 

predominate. The cavern walls are coated with metamorphic 

quartz. The host dolomite is not hydrothermally altered. The 

one large deposit of this type occurs in the northern part 

of the Khabarovsk province and is hosted mainly in 

subhorizontal dolomite marble that, along with other 

miogeoclinal sedimentary rocks, form the Late Proterozoic 

and Early Paleozoic sedimentary cover of the Stanovoy block 

of the North Asian Craton. The origin of the deposit is 

speculative. According B. Zalischak (written commun., 1992) 

the deposit formed by discharge of hydrothermal solution 

along a layer of porous dolomite. A sudden pressure fall 

resulted in a blast. An U-Pb isotopic age of about 100 Ma 

was obtain for hydrozircon (J.N. Aleinikoff, written 

commun., 1993).



Sedimentary phosphorite (Shkolnik, 1973)



        This deposit type consists of breccia composed of 

phosphorite, quartz, dolomite, and calcite that are closely 

associated with calcareous marine reef complexes. The reef 

complexes occur in sequences of jasper, shale, siltstone, 

and mafic volcanic rocks. Phosphorite breccias formed along 

the reef shelf and consist of fragments of primary 

phosphorite, limestone, and dolomite, and rarely jasper, 

volcanic rocks, chert, and shale. Primary phosphorite is 

rare and occurs as lenses of a coquina composed of 

inarticulate brachiopods and partly by trilobites that 

posses with phosphate-bearing shells. The boundaries of 

deposits are complex and are defined by the occurrence of 

phosphorite fragments in breccias. The length of the 

deposits ranges from a few tens of meters to several 

kilometers; the thickness ranges from 0.5 to 40 meters. The 

deposits are generally complex and discontinuous. The 

deposit type occurs mainly in the Galam terrane in the 

Russian Southeast and is associated with volcanogenic Mn and 

Fe deposits. The principal phosphorite deposits in the Galam 

terrane are the North-Shantary, Ir-Nimiiskoe, Nelkanskoe, 

and Lagapskoe deposits.



Deposits Related to Calc-Alkaline and Alkaline

Granitic Intrusions- Veins and Replacements



Polymetallic veins (D.P. Cox in Cox and Singer, 1986; N.A. 

Goryachev, this study)



        This deposit type consists of quartz-carbonate veins 

often with Ag-bearing minerals, gold, and associated base-

metal sulfides. The veins are related to hypabyssal 

intrusions in sedimentary and metamorphic terranes, or to 

metamorphic fluids forming during waning regional 

metamorphism. The associated intrusions range in composition 

from calcalkaline to alkaline and occur in dike swarms, 

hypabyssal intrusions, small to moderate size intermediate 

to granitic plutons, locally associated with andesite to 

rhyolite flows. The deposit minerals include pyrite, and 

sphalerite, sometimes with chalcopyrite, galena, 

arsenopyrite, tetrahedrite, Ag sulfosalts, native gold, 

electrum, and argentite. Alteration consists of wide 

propylitic zones, and narrow sericite and argillite zones. 

The depositional environment is near-surface fractures and 

breccias within thermal aureoles of small to moderate-size 

intrusions, including within the intrusions.



        In the Russian Northeast, polymetallic veins are divided 

into: (1) Au-polymetallic veins that contain gold and Pb-Zn-

Cu sulfide minerals and arsenopyrite; (2) polymetallic veins 

with varying amounts of cassiterite and (or) stannite with 

abundant Fe, Pb, Zn, and Cu sulfide minerals; and (3) Ag-

polymetallic veins enriched with galena, and Ag and Pb 

sulfosalts. In this region, polymetallic veins occur: (1) 

mainly in flysch or olistostromes in Mesozoic accretionary 

wedges; or (2) sometimes in postaccretionary volcanic rocks. 

Polymetallic veins are analogs of skarn deposits and occur 

where noncalcareous clastic rocks dominate instead of 

carbonate rocks.



Sb-Au veins (simple Sb deposits) (J.D. Bliss and G.A. Orris 

in Cox and Singer, 1986; Nokleberg and others, 1987)



        This deposit type consists of massive to disseminated 

stibnite and lesser gold in quartz-carbonate veins, pods, 

and stockworks that occur in or adjacent to brecciated or 

sheared fault zones, in sedimentary, volcanic and 

metamorphic rocks, adjacent to granitic plutons, in contact 

aureoles around granitic plutons, and peripheries of 

granodiorite, granite, and monzonite plutons. Some Sb-Au 

vein deposits grade into polymetallic vein deposits. 

Associated minerals are mainly arsenopyrite, chalcopyrite, 

and tetrahedrite, and sometimes cinnabar, galena, and 

sulfosalts. Alteration minerals are mainly quartz, sericite, 

and clay minerals. Associated granitic plutons are often 

strongly peraluminous. The depositional environment is 

faults and shear zones, epizonal fractures adjacent to or 

within the margins of epizonal granitic plutons.



Sn quartz veins (Rudny Gory or Replacement Sn) (Kosygin and 

Kulish, 1984; W.D. Sinclair and R.V. Kirkham in Eckstrand, 

1984; B.L. Reed in Cox and Singer, 1986; Lugov, 1986)



        This deposit type consists of simple and complex 

infilling and replacement veins, vein systems, and 

stockworks that occur in the apices of collisional mesozonal 

and hypabyssal granitoid plutons, and above granitic domes. 

The host rocks are commonly metamorphosed shale, sandstone, 

and sometimes carbonate rocks. This deposit type is commonly 

associated with multiple intrusions of biotite, two-mica, 

alkalic, alaskite granites. Granite, pegmatite and aplite 

dikes are common. Volatiles are dominated by fluorine, and 

boron content of granites is low. The deposits tend to occur 

within or above the apices of granitic cusps and ridges. The 

deposit minerals are cassiterite, wolframite, albite, 

muscovite, topaz, fluorite, arsenopyrite and lllingite. 

Less common are potassium feldspar, tourmaline, beryl, 

scheelite, molybdenite, Ta-Ni-minerals, Bi-minerals, 

pyrrhotite, sphalerite, galena, and chalcopyrite. Complex 

Sn-W ores are dominate. Quartz is the dominant gangue 

mineral. The dominant wall rock alteration is formation of 

greisen. The deposit type is associated with Sn-greisen and 

Sn-skarn, wolframite-quartz veins, and U and F deposits.



Sn silicate-sulfide veins (Cornish type) (Kosygin and 

Kulish, 1984; W.D. Sinclair and R.V. Kirkham in Eckstrand, 

1984; Lugov, 1986; B.L. Reed in Cox and Singer, 1986)



        This deposit type consists of fissure veins, mineralized 

zones, stockworks, and pipe-like bodies related to multiple 

granitoid plutons, and to isolated small intrusions of 

gabbro-diorite, quartz diorite, and potassic alaskite 

granites. Late-stage tourmaline-bearing granites and 

pegmatites also occur. The deposit type commonly occurs in 

late orogenic to post-orogenic settings. Sn mineralization 

is commonly fault-controlled, and occurs near and above 

intrusive rocks. The deposit minerals are mainly tourmaline, 

chlorite, and quartz, with lesser cassiterite, pyrrhotite, 

pyrite, chalcopyrite, galena, sphalerite, arsenopyrite, 

wolframite, scheelite, bismuthinite, axinite, fluorite, 

muscovite, sericite, stannite, sulfostannates, Pb-, Sb-, Cu- 

and Ag-sulfosalts, gold, silver, stibnite, calcite, and clay 

minerals. Alteration minerals are tourmaline, muscovite, 

quartz, and chlorite. The deposit type includes tourmaline 

and chlorite subtypes. The upper and lower portions of ore 

vein systems are dominated by sulfides, and silicates and 

quartz, respectively.



Sn polymetallic veins (Southern Bolivian type) (Lugov, 1986; 

Yukio Togashi in Cox and Singer, 1986)



        This deposit type consists of cassiterite and associated 

minerals in veins, stockworks, mineralized zones and breccia 

pipes. The deposits are controlled by sets of regional 

faults and fractures in subvolcanic and volcanic structures. 

Associated igneous rocks are hypabyssal and subvolcanic 

diorite, granodiorite, and hypabyssal-andesite intrusions, 

and felsic, intermediate, and mafic dikes. The deposit 

minerals are cassiterite, pyrrhotite, pyrite, stannite, 

sphalerite, galena, chalcopyrite, wolframite, tetrahedrite, 

tennantite, Bi-minerals, sulfostannates, arsenopyrite, Pb-, 

Au-, and Sb- sulfosalts, with subordinate quartz, Mn-Fe 

carbonate minerals, sericite, and kaolinite. Tourmaline and 

chlorite may also occur. This deposit type may also include 

Sn-Ag deposits containing freibergite, pyrargyrite, 

polybasite, andorite, stephanite, argentite, argyrodite, 

canfieldite and others. The principal wall-rock alterations 

are sericite, chlorite, quartz, kaolinite, and alunite. The 

deposit type is associated with Sn-silicate-sulfide and Ag 

polymetallic vein, rhyolite-hosted Sn, porphyry Sn, and Au-

Ag epithermal vein deposits. The depositional environment is 

fissures in and around felsic, continental marginal volcanic 

arcs. Mineralization occurs in volcanic rocks above 

intrusions, but may be far-removed from granitic rocks.



Co-arsenide polymetallic veins (Borisenko and others, 1984; 

(R.A. Eremin and V.I. Shpikerman, this study)



        This deposit type consists of quartz-tourmaline and 

quartz-chlorite veins containing Co, As, Bi, and Ag and Au 

minerals. The veins are associated with hypabyssal 

intrusions varying from diorite to granite, and widespread 

albitized granite-porphyry dikes. Mineralization occurs in: 

(1) fractures and in brecciated zones in siltstone, shale, 

and sandstone; (2) contact metamorphic aureoles around 

intrusions or, more seldom, in intrusions; and (3) sometimes 

greisen and skarn. The deposits are often confined to cross-

faults. The deposit minerals are arsenopyrite, pyrite, 

pyrrhotite, lllingite, cobaltite, skutterudite, smaltite, 

glaucodot, chloantite, bismuthinite, and Au-, Ag-, Pb-, and 

Bi-tellurides and selenides. Vein gangue minerals are 

quartz, chlorite, tourmaline, calcite, fluorite, and 

adularia.



Carbonatite-related Ta, Nb, REE stockwork and vein (Smirnov, 

1982; Dawson and Curie, 1984)



        This deposit type consists of stockworks, metasomatic 

veins, and lenses with various Ta-Nb and REE minerals. The 

ore minerals include pyrochlore, betafite, bastnasite, 

parisite, monazite, columbite, chevkinite, yttrialite, 

melanocerite, yttrotitanite, hydrothorite, and zircon. Ore 

mineralization is often associated with alkaline metasomatic 

rocks (fenite) that alter alkaline granite and syenite. The 

stockworks, vein, and lenses are associated with alkaline 

igneous complexes that presumably include carbonatite at 

depth. The igneous complexes include large zoned batholiths, 

zoned stocks, alkalic dikes series, and carbonate veins. The 

zoned batholiths and stocks generally contain two or more of 

the following lithologies: pyroxenite, gabbro, urtites, 

ijolite, foyaite, nephelinite, alkaline syenite, granite, 

and various carbonatites. Zonation commonly consists of 

carbonatites in the center, medial zones of ultramafic 

rocks, and peripheral zones of ijolite and nepheline 

syenite. Locally the zonation sequence may be reversed or 

more complex. The carbonatites generally consist of various 

assemblages of augite-diopside-calcite, forsterite-calcite, 

aegirine-dolomite, aegirine-ankerite, calcite, ankerite, and 

other minerals. This type of deposit is interpreted as 

having formed during craton rifting, or within terranes that 

formed by rifting of cratons.



Deposits Related to Calc-Alkaline and Alkaline

Granitic Intrusions - Skarns and Greisens



Cu (Fe, Au, Ag, Mo) skarn (contact metasomatic) (D.P. Cox 

and T.G. Theodore in Cox and Singer, 1986)



        This deposit type consists of chalcopyrite, magnetite, 

and pyrrhotite in calc-silicate skarns that replace 

carbonate rocks along intrusive contacts with plutons 

ranging in composition from quartz diorite to granite, and 

from diorite to syenite. Zn-Pb-rich skarns tend to occur 

farther from the intrusion; Cu- and Au-rich skarns tend to 

occur closer to the intrusion. Associated minerals are 

pyrite, hematite, galena, molybdenite, sphalerite, and 

scheelite. Mineralization is multistage, with several stages 

of mineral deposition. The deposit type is commonly 

associated with porphyry Cu-Mo deposits. The depositional 

environment is mainly calcareous sedimentary sequences 

intruded by felsic to intermediate granitic plutons.



Zn-Pb (Ag, Cu, W) skarn (contact metasomatic) and 

associated Manto replacement deposits (D.P. Cox in Cox and 

Singer, 1986)



        This deposit type consists of sphalerite and galena in 

calc-silicate skarns that replace carbonate rocks along 

intrusive contacts with plutons varying in composition from 

quartz diorite to granite, and from diorite to syenite. Zn-

Pb-rich skarns tend to occur farther from the intrusion 

relative to Cu- and Au-rich skarns. Associated minerals are 

pyrite, chalcopyrite, hematite, magnetite, bornite, 

arsenopyrite, and pyrrhotite. Metasomatic replacements 

consist of a wide variety of calc-silicate and related 

minerals. In the Russian Far East, the deposit type 

generally occurs at a considerable distance from source 

granitic intrusions, at the contacts of limestones with 

siltstones and felsic volcanic rocks. Ore bodies are rather 

narrow, but may extend down dip to 1 km. The deposits are 

controlled by ring faults around volcanic-tectonic 

depressions. The depositional environment is mainly 

calcareous sedimentary sequences intruded by felsic to 

intermediate granitic plutons.



Au, Co, and As skarn (Nekrasov and Gamyanin, 1962; Bakharev 

and others, 1988; N.A. Goryachev, this study)



        This deposit type forms along the contacts between 

siltstone and marble beds during contact metamorphism near 

intrusions of granodiorite and granite. The skarn is 

typically composed of pyroxene, grossularite-andradite 

garnet, and lesser axinite and scapolite. The ore bodies 

consist of small masses of sulfoarsenides and arsenides 

along with gersdorffite, arsenopyrite, lollingite, and 

cobaltite. Native gold occurs in association with bismuth 

and Te-minerals, including native bismuth, joseites, 

hedlyite, and bismuthine. Gold grade ranges up to 20 g/t; 

size is usually less than 0.1 mm, and fineness ranges from 

640 to 999.



W skarn and greisen (adapted from D.P. Cox in Cox and 

Singer, 1986)



        This deposit type consists of scheelite in calc-silicate 

skarns that replace carbonate rocks along or near intrusive 

contacts of quartz diorite to granite plutons. Associated 

minerals are molybdenite, pyrrhotite, sphalerite, 

chalcopyrite, bornite, pyrite, and magnetite. Metasomatic 

replacements consist of a wide variety of calc-silicate and 

related minerals. In the Russian Far East, scheelite 

typically occurs in quartz-topaz and quartz-mica greisen 

that formed during replacement of older skarns. The 

depositional environment is along contacts and in roof 

pendants in batholiths, and in contact metamorphic aureoles 

of stocks that intrude carbonate rocks.



Fe (Au, Cu, W, Sn) skarn (D.P. Cox in Cox and Singer, 1986)



        This deposit type consists of magnetite and (or) Fe 

sulfides in calc-silicate skarn that replace carbonate rocks 

or calcareous clastic rocks along intrusive contacts with 

diorite, granodiorite, granite, and coeval volcanic rocks. 

The chief associated mineral is chalcopyrite. Metasomatic 

replacements consist of a wide variety of calc-silicate and 

related minerals. The depositional environment is calcareous 

sedimentary sequences intruded by granitic or siliceous 

volcanic stocks.



Sn greisen and skarn (B.L. Reed in Cox and Singer, 1986)



        These two deposit types commonly occur in the same area, 

and may grade into one another. The Sn greisen deposit type 

consists of disseminated cassiterite, cassiterite-bearing 

veinlets, and Sn sulfosalts in stockworks, lenses, pipes, 

and breccia in granite altered to greisen, mainly biotite 

and (or) muscovite leucogranite emplaced in a mesozonal to 

deep volcanic environment. Sn greisens are generally 

postmagmatic and are associated with late-stage, 

fractionated granitic magmas. Associated minerals include 

molybdenite, arsenopyrite, beryl, scheelite, and wolframite. 

Alteration minerals consist of incipient to massive 

replacement by quartz, muscovite, tourmaline, and fluorite.



        The Sn skarn deposit type consists of Sn, W, and Be 

minerals in skarns, veins, stockworks, and greisen near 

intrusive contacts between generally epizonal(?) granitic 

plutons and limestone. The deposit minerals include 

cassiterite, sometimes with scheelite, sphalerite, 

chalcopyrite, pyrrhotite, magnetite, and fluorite. 

Alteration consists of greisen near granite margins, and 

metasomatic andradite, idocrase, amphibole, chlorite, 

chrysoberyl, and mica in skarn.



Sn-B (Fe) Skarn (Ludwigtite type) (Lisitsin, 1984; V.I. 

Shpikerman, this study)



        This deposit consists of metasomatic replacement of 

dolomite by mainly ludwigite and magnetite adjacent to 

granitic plutons thereby forming Sn-B (Fe) magnesium skarn 

deposits. Ludwigite forms up to 70 to 80 percent of some ore 

bodies, and Sn occurs as an isomorphic admixture in 

ludwigite. Other minerals in the magnesian skarns include 

magnetite, suanit (Mg2B5O), ascharite, kotoite, datolite, 

harkerite, monticellite, fluroborite, clinohumite, calcite, 

periclase, forsterite, diopside, vesuvianite, brucite, 

garnet, axinite, phlogopite, serpentine, spinel, and talc. 

Interlayered limestone is metasomatically replaced by 

pyroxene-garnet-calcite skarn that is commonly altered to 

greisen thereby forming Sn skarn composed of cassiterite, 

scheelite, pyrrhotite, arsenopyrite, sphalerite, 

chalcopyrite, and lllingite. The magnesium and associated 

calcic skarn ore bodies generally form near highly irregular 

(convoluted) contacts of granite plutons, and in large 

xenoliths of carbonate rocks. Most granitic rocks associated 

with these deposits are interpreted as having formed in 

collision environments.



Boron skarn (datolite type) (Nosenko and others, 1990; 

Ratkin, and others, 1992; Ratkin and Watson, 1993)



        This deposit type consists of a boron skarn composed of 

danburite and datolite that is associated with garnet-

hedenbergite-wollastonite skarn. The boron-bearing skarn is 

interpreted as having formed during successive metasomatic 

replacement of limestone with silicates (wollastonite, 

grossularite-andradite, and hedenbergite) and subsequently 

by borosilicates (danburite, datolite, and axinite), quartz, 

and calcite. The deposit is characterized by thin-banded 

wollastonite that forms kidney-shaped aggregates of pyroxene 

and datolite that formed the walls of paleohydrothermal 

cavities in limestone. The hydrothermal cavities occur to 

depths of up to 500 m from the paleosurface, above a zone of 

a metasomatic wollastonite and grossularite. The central 

part of these cavities (0.5 to 50.0 m across) was filled 

with danburite druses. Danburite was decomposed after the 

second (boron) metasomatic event, and remobilized boron was 

redeposited at higher paleogypsometric levels as datolite 

associated with garnet-hedenbergite skarn. The origin of 

neighboring Pb-Zn deposits is related to these late skarns. 

Boron isotopic data indicate the source for boron solutions 

was a deep-seated granitoid intrusion. The formation of 

early grossular-wollastonite skarns, thin-banded 

wollastonite aggregates with datolite, and danburite 

accumulations occurred, by geological data, at depths, 

simultaneous to the formation of postaccretion ignimbrite 

sequence, overlying the accretionary wedge. The geologic 

setting for the deposit is large tectonic lens of limestone, 

with lateral dimensions of 0.5 by 2.0 km, in an accretionary 

wedge containing a highly-deformed matrix of siltstone and 

sandstone matrix. The accretionary wedge is overlain by 

felsic volcanic rocks. The one example of this deposit is 

the large Dalnegorsk B mine in the Russia Southeast that 

constitutes the main source of boron in Russia.



Fluorite greisen (Govorov, 1977)



        The deposit type consists of fine-grained, dark-violet 

rock composed of fluorite (63 to 66%) and micaceous 

minerals, mainly muscovite (25 to 35%), along with lesser 

ephesite and phlogopite. Subordinate minerals are (in 

decreasing order) tourmaline, sellaite, cassiterite, topaz, 

sulfides, and quartz. The ore bodies occur as veins and 

concordant to limestone layers as lenticular and flame-shape 

bodies, consist of apocarbonate greisens. The deposit type 

occur in limestone intruded by lithium-fluorine S-type 

granites. Metasomatic rocks, replacing limestone, occur at 

and above the contact with granitic intrusions. Pegmatoid-

type muscovite-quartz veins with molybdenite-cassiterite-

salite, vesuvianite-salite-andradite, and scapolite skarn 

also occur near intrusive contacts and are interpreted as 

having formed prior the formation of fluorite-mica greisen. 

Geologic setting is thick clastic limestone sequences that 

formed along an active continental margin. Boron isotopic 

composition of tourmaline indicate a primary evaporite 

source (V. Ratkin, written commun., 1994) suggesting that 

deep-seated evaporites in the zone of granitic magma 

generation were the source of fluorine. Scarce quartz and 

the absence of paragenetic calcite suggest an extremely high 

activity of fluorine in silica-poor solutions. The deposit 

closest to this type in Alaska is at Lost River. The largest 

deposit of this type in the southern Far East Russia is at 

Voznesenka that constitutes the largest known Russian 

fluorspar deposit.



Deposits Related to Calc-Alkaline and Alkaline Granitic 

Intrusions-Porphyry and Granitic Plutons-Hosted Deposits



Porphyry Cu-Mo (Au, Ag) (D.P. Cox in Cox and Singer, 1986; 

Titley, 1993)



        This deposit type consists of stockwork veinlets and 

veins of quartz, chalcopyrite, and molybdenite in or near 

porphyritic intermediate to felsic intrusions. The veinlets 

and veins contain mainly quartz and carbonate minerals. The 

intrusions occur mainly in stocks and breccia pipes that 

intrude granitic, volcanic, or sedimentary rocks. Associated 

minerals are pyrite and peripheral sphalerite, galena, and 

gold. Alteration minerals consist of quartz, K-feldspar, and 

biotite or chlorite. Most deposits exhibit varying amounts 

of hypogene alteration, including sodic, potassic, and 

phyllic alteration. Alteration is systematic, but variable 

between districts. Supergene alteration is a key factor in 

the initial discovery of deposits. The host igneous rocks 

are felsic and calc-alkalic. Widespread, episodic 

development of abundant joints in intrusions and wall rocks. 

The depositional environment is high-level intrusive 

porphyries that are contemporaneous with abundant dikes, 

faults, and breccia pipes that formed in the evolution of 

andesite stratovolcanoes. The tectonic environment is mainly 

weakly to strongly alkalic granitic plutons emplaced in 

back-arc settings of subduction zones.



Porphyry Mo (W, Sn, Bi) (T.G. Theodore in Cox and Singer, 

1986; Carten and others, 1993)



        The porphyry Mo deposit type consists of quartz-

molybdenite stockwork veinlets in granitic porphyries and 

adjacent country rock. The porphyries range in composition 

from tonalite to granodiorite to monzogranite. Associated 

minerals are pyrite, scheelite, chalcopyrite, and 

tetrahedrite. Alteration consists of potassic grading 

outward to propylitic, sometimes with phyllic and argillic 

overprints. Deposit type divided into two associations: (1) 

high-grade, rift-related deposits with fluorine-rich, highly 

evolved rhyolitic stocks that belong to a high-silica 

rhyolite-alkalic suite; and (2) low-grade, arc-related 

deposits accompanied by fluorine-poor, calc-alkalic stocks 

or plutons that belong to a differentiated monzogranite 

suite. The high-grade, fluorine-rich deposits are also 

associated with intraplate alkaline igneous rocks. The 

depositional environment for porphyry Mo deposits is 

epizonal levels of a thick continental crust.



Porphyry Sn (B.L. Reed in Cox and Singer, 1986; Evstrakhin, 

1988; Menzie and others, 1992; R.A. Eremin, this study)



        This deposit type consists of mainly cassiterite and 

associated minerals in stockworks, veinlets, and 

disseminations that occur in veins, pipes, and shoots. The 

deposit minerals are cassiterite, quartz, pyrrhotite, 

pyrite, arsenopyrite, chalcopyrite, sphalerite, galena, 

stannite, wolframite, muscovite, chlorite, tourmaline, 

albite, adularia, siderite, rhodochrosite, calcite, topaz, 

fluorite, sulfostannates, and Ag and Bi minerals. 

Mineralization occurs in shallow complex multiphase granitic 

plutons, granitic porphyry stocks, subvolcanic and volcanic 

rhyolite breccias, and also in coeval volcanic rocks and 

surrounding clastic rocks. Associated features are magmatic-

hydrothermal breccias, and extensive metasomatic propylitic 

alteration along with formation of quartz, tourmaline, 

sulfide minerals, and sericite. Some deposits exhibit a 

quartz-tourmaline core with a peripheral zone of sericite. 

The deposit type is often associated with Sn- and Ag-bearing 

polymetallic veins. Other features of this deposit type are 

complex ore composition, variable mineral composition, 

extensive development of stockworks, extensive metasomatic 

alteration, both veinlet and disseminated. The depositional 

environment is mainly volcanic-plutonic igneous arcs formed 

on continental crust. For simplicity, this deposit type also 

includes Sn deposits that occur in granitic plutonic rocks. 

This type of granitoid-hosted Sn deposit may eventually be 

defined as a new mineral deposit type.



Granitoid-related Au (R.I. Thorpe and J.M. Franklin, in 

Eckstrand, 1984; Sidorov and Rozenblum, 1989; Aksenova, 

1990; Gamyanin and Goryachev, 1990, 1991; Sillitoe, 1993b; 

N.A. Goryachev, this study)



        This deposit type consists of two subtypes: (1) porphyry 

Au; and (2) Au-REE quartz vein. The porphyry Au subtype 

consists of fissure veins, en-echelon vein systems, and 

veinlet-stockwork zones with disseminated gold and sulfide 

minerals that occur generally in complex small granitic 

intrusions in volcanic-plutonic complexes. The deposit 

minerals are native gold, Au-bearing tellurides and sulfide 

minerals, with accessory quartz, tourmaline, muscovite, 

sericite, chlorite, feldspar, carbonate minerals, and 

fluorite. Disseminated sulfide minerals in wall rocks, 

especially arsenopyrite, are commonly enriched in Au and Ag. 

Alteration to greisen is common with formation of quartz, 

sericite, tourmaline, chlorite. Plutonic rock composition 

includes gabbro, diorite, granodiorite, and granite of both 

calc-alkalic and sub-alkalic compositions. The deposits are 

associated with composite porphyry stocks of steep, 

cylindrical form that commonly intrude coeval volcanic 

piles. Stocks and associated volcanic rocks range in 

composition from low-potassium calc-alkalic through high-

potassium calc-alkalic to potassic alkalic. The deposits may 

occur as disseminations within granitic plutons, at apices 

of plutons, or in contact metamorphic aureoles. The deposit 

type displays systematic mineralogy and chemical 

environment; and is often associated with polymetallic vein 

deposits with disseminated Au-bearing sulfide minerals, Au-

bearing epithermal vein, and porphyry deposits. Advanced 

argillic alteration is widespread in shallow parts of 

deposit. Underlying sericitic alteration is typically minor. 

In Alaska and the Canadian Cordillera, the depositional 

environment is tentatively interpreted as subduction-

related, epizonal plutons intruded into miogeoclinal 

sedimentary rocks that in some cases were regionally 

metamorphosed and deformed before intrusion.



        The Au-REE quartz vein subtype, common in the Russian 

Northeast, consists of quartz veins and stockworks that 

occur in the apical portions of small granodiorite and 

granite plutons, and rarely in contact metamorphosed rocks 

above the plutons. The quartz veins and stockworks are 

dominated by quartz along with muscovite, tourmaline, and K-

feldspar. The main deposit minerals are gold, arsenopyrite 

and Co-arsenopyrite, lollingite, wolframite, scheelite, 

pyrrhotite, and niccolite. Native gold is associated with 

bismuth and Bi-Te-minerals. Au-Ag telluride minerals are 

scarce. The host rocks exhibit incipient alteration to 

greisen with occurrence of quartz, white mica, carbonate 

minerals, and chlorite. The quartz veins and stockworks are 

often associated with post-contact metamorphic Au-quartz and 

Sn-W-quartz veins.



Felsic plutonic U-REE (Nokleberg and others, 1987)



        This deposit type consists of disseminated uranium 

minerals, thorium minerals, and REE-minerals in fissure 

veins and alkalic granite dikes in or along the margins of 

alkalic and peralkalic granitic plutons, or in granitic 

plutons, including granite, alkalic granite, granodiorite, 

syenite, and monzonite. The deposit minerals include 

allanite, thorite, uraninite, bastnaesite, monazite, 

uranothorianite, and xenotime, sometimes with galena and 

fluorite. The depositional environment is mainly the margins 

of epizonal to mesozonal granitic plutons.

W veins (Kosygin and Kulish, 1984; D.P. Cox and W.C. Bagby 

in Cox and Singer, 1986)



        This deposit type consists mainly of massive and 

disseminated wolframite and molybdenite in quartz veins. 

Other deposit minerals are bismuthinite, pyrite, pyrrhotite, 

arsenopyrite, bornite, chalcopyrite, scheelite, cassiterite, 

beryl, and fluorite. The veins occur in the upper level, 

apices of granitic plutons, including alaskite, and in 

peripheral, contact metamorphosed sandstone and shale. 

Associated hydrothermal alteration includes formation of 

greisen, albite, chlorite, and tourmaline. The depositional 

environment is tensional fractures in epizonal granitoid 

plutons that intruded, and in some cases formed from 

anatectic melting of continental crust. The deposit type is 

sometimes associated with Sn-W vein, Mo-W vein, and Sn 

greisen deposits.



Deposits Related to Mafic and Ultramafic Rocks

Zoned mafic-ultramafic Cr-PGE (Cu, Ni, Au, Co, Ti, or Fe) 

(Alaskan PGE) (N.J Page and Floyd Gray in Cox and Singer, 

1986)



        This deposit type consists of crosscutting ultramafic to 

mafic plutons with approximately concentric zoning that 

contain chromite, native PGE, PGE minerals and alloys, and 

Ti-V magnetite. The deposit minerals include combinations of 

chromite, PGE minerals and alloys, pentlandite, pyrrhotite, 

Ti-V magnetite, bornite, and chalcopyrite. In most areas of 

Alaska, the depositional environment consists of 

intermediate-level intrusion of mafic and (or) ultramafic 

plutons that are interpreted as the deeper-level magmatic 

roots to island-arc volcanoes. 



Zoned ultramafic, mafic, felsic, and alkalic PGE-Cr  and 

apatite-Ti (Marakushev and others, 1990)



        This deposit type consists of veinlets, disseminations, 

and zones of hydrothermal metasomatic alteration in dunites 

associated with ultramafic to mafic alkalic-potassic 

intrusions. PGE minerals are associated with, and are 

intergrown with chromite and olivine. In metasomatic zones, 

where chromium pyroxene occurs, PGE minerals are intergrown 

with magnetite, pyroxene, and phlogopite. The major PGE 

mineral is ferroplatinum with inclusions of iridosmine. 

Accessory sulfide and arsenide minerals also occur, 

including cooperite, sperrylite, hollingworthite, konderite, 

inaglyite, laurite-euclimanite, and others. In associated 

pyroxene-hornblende gabbro and pyroxenites intrusions, 

apatite-Ti minerals may also occur, including disseminated 

apatite, titanomagnetite, ilmenite, and local PGE minerals. 

Weathered pyroxenites could be a raw material for 

vermiculite. The depositional environment is the 

intermediate-level intrusion of mafic and (or) ultramafic 

plutons that are interpreted as the magmatic roots to 

island-arc volcanoes.



Anorthosite apatite-Ti-Fe (Kosygin and Kulish, 1984; Force 

in Cox and Singer, 1986)



        This deposit type occurs in anorthosite plutons composed 

of andesine and andesine-labradorite. The anorthosite 

plutons are highly-alkalic and are associated with gabbro, 

ferrodiorite, syenite, alkalic granite, and sometimes 

mangerite that intrude granulite-facies country rocks. The 

principal deposit minerals are apatite, titanomagnetite, and 

ilmenite that occur either as: (1) disseminations near 

melanocratic gabbro, pyroxenites, and dunites along the 

margins of the anorthosite plutons; or (2) rich apatite 

(nelsonite) veins that occur in tectonically weak zones. 

Associated minerals are lesser ilmenite and magnetite. The 

depositional environment is intrusion into the lower crust 

under hot, dry conditions.



Gabbroic Ni-Cu (synorogenic-synvolcanic; irregular gabbro 

pipes and stocks) (N.J Page in Cox and Singer, 1986)



        This deposit type consists of massive lenses, matrix, and 

disseminated sulfides in small to medium-size composite 

mafic and ultramafic intrusions in metamorphic belts of 

metasedimentary and metavolcanic rocks. The deposit minerals 

include pyrrhotite, pentlandite, and chalcopyrite, sometimes 

with pyrite, Ti- or Cr-magnetite, and PGE minerals and 

alloys. Accessory Co-minerals also occur in some deposits. 

In most areas of Alaska, the depositional environment 

consists of post-metamorphic and post-deformational, 

intermediate-level intrusion of norite, gabbro-norite, and 

ultramafic rocks.



Podiform Cr (J.P. Albers in Cox and Singer, 1986)



        This deposit type consists of podlike masses of chromite 

in the ultramafic parts of ophiolite complexes, locally 

intensely faulted and dismembered. The host rock types are 

mainly dunite and harzburgite, commonly serpentinized. The 

depositional environment consists of magmatic cumulates in 

elongate magma pockets. Associated minerals are magnetite 

and PGE-minerals and alloys.



Hornblende-Peridotite Cu-Ni (Shcheka and Chubarov, 1987)



        This deposit type consists of pentlandite, Zn-bearing 

chrome spinel, pyrrhotite, chalcopyrite, and bornite that 

occur in veinlets and as disseminations in hornblendite-

peridotite-norite-diorite intrusions. A paragenetic sequence 

of magmatic amphibole, olivine commonly garnet indicate 

formation at great depth. The host intrusions are 

characterized by graphite and native iron, and subordinate 

aluminum and magnesium-free chromite that indicate reducing 

crystallization conditions. Examples are the Kvinum, 

Shanuch, and Kuvalorog deposits in the southern Kamchatka 

Peninsula.



Serpentine-hosted asbestos (N.J Page in Cox and Singer, 

1986)

        This deposit type consists of chrysotile asbestos 

developed in stockworks in serpentinized ultramafic rocks. 

The depositional environment is usually an ophiolite 

sequence, sometimes with later deformation of igneous 

intrusion. Associated minerals are magnetite, brucite, talc, 

and tremolite.



Deposits Related to Regionally Metamorphosed Rocks



Au quartz veins (includes concordant vein, and shear zone 

Au) (B.R. Berger in Cox and Singer, 1986)



        This deposit type includes low-sulfide Au quartz vein, 

turbidite-hosted, concordant vein, and shear zone Au 

deposits types and consists of gold in massive, persistent 

quartz veins in regionally metamorphosed volcanic rocks, 

metamorphosed graywacke, chert, and shale. The veins are 

generally late synmetamorphic to postmetamorphic and locally 

cut granitic rocks. Associated minerals are minor pyrite, 

galena, sphalerite, chalcopyrite, arsenopyrite, and 

pyrrhotite. Alteration minerals include quartz, siderite, 

albite, and carbonate minerals. The depositional environment 

is low-grade metamorphic belts.



Disseminated Au-sulfide (Maiskoe type) (Sidorov, 1987)



        This deposit type consists of fine-grained, disseminated 

sulfide minerals with subordinate veinlets and veins that 

occur in deformed and metamorphosed clastic metasedimentary 

rocks, mainly black shale. Gold occurs mainly in finely-

dispersed sulfide minerals, mainly in acicular arsenopyrite, 

and Au-rich pyrite. Other deposit minerals are subordinate 

pyrrhotite, sphalerite, galena, chalcopyrite, various 

sulfosalts, quartz, and stibnite. Quartz-stibnite is the 

latest-formed assemblage. The deposits occur at the base of 

volcanic arcs in orogenic zones, and are controlled by 

extensive ductile shear zones, complex folds, and dome 

structures. Host rocks generally exhibit greenschist facies 

metamorphism. No relation exists between deposit type and 

granitic intrusions, except for local dikes. This deposit 

type may be associated with epithermal vein, granitoid-

related Au, polymetallic vein, and various Sb and Hg 

deposits. The deposits type is interpreted to have formed 

from deep-seated, reducing, hydrothermal-metamorphic fluids.



Clastic sediment-hosted Sb-Au (Berger, 1978, 1993)



        This deposit type consists of stibnite and associated 

minerals that occur in simple and complex ladder and 

reticulate veins and veinlets, sometimes with subconformable 

disseminations. The main ore minerals are stibnite, 

berthierite, pyrite, arsenopyrite, and gold, with 

subordinate sphalerite, galena, chalcopyrite, tetrahedrite, 

chalostibite, scheelite, sphalerite, galena, tetrahedrite, 

pyrrhotite, marcasite, gudmundite, gersdorffite, native 

antimony, and native silver. Gangue minerals are mainly 

quartz and lesser ankerite, and lesser calcite, dolomite, 

siderite, sericite, and gypsum. Wall rocks are altered to 

varying combinations of quartz, carbonate, sericite, and 

pyrite. The host rocks for this deposit are: (1) Archean 

greenschist derived from mafic and ultramafic volcanic and 

volcaniclastic rocks; (2) interbedded carbonaceous black 

shale and volcanogenic-clastic rocks; or (3) to a lesser 

extent, retrogressively-metamorphosed granitic rocks. The 

deposit type occurs mainly in linear zones of folding and 

mylonites associated with regional strike-slip faults. 

Deposit type is associated with low-grade greenschist facies 

regional metamorphism; this association suggests a 

hydrothermal-metamorphic origin. The depositional 

environment is strongly-deformed fold belts developed along 

the former intracratonic rift troughs. The deposit type may 

also be associated with Au-quartz vein deposits.



Cu-Ag quartz vein (vein Cu) (Nokleberg and others, 1987)



        This deposit type consists of Cu sulfides and accessory 

Ag in quartz veins and disseminations in weakly regionally 

metamorphosed mafic igneous rocks, mainly basalt and gabbro, 

and in lesser andesite and dacite. The veins are generally 

late-stage metamorphic. The deposit minerals include 

chalcopyrite, bornite, lesser chalcocite, and rare native 

copper. Alteration minerals include epidote, chlorite, 

actinolite, albite, quartz, and zeolites. The depositional 

environment is low-grade metamorphic belts.



Kennecott Cu (adapted from basaltic Cu deposit type by D.P. 

Cox in Cox and Singer, 1986, and from Nokleberg and others, 

1987)

        This deposit type consists of Cu-sulfides in large pipes 

and lenses in carbonate rocks within a few tens of meters of 

disconformably underlying subaerial basalt. Subsequent 

subaerial erosion of Cu-bearing basalt, and low-grade 

regional metamorphism may concentrate Cu-sulfides into pipes 

and lenses. The deposit minerals are chalcocite and lesser 

bornite, chalcopyrite, other Cu sulfide minerals, and 

oxidized Cu minerals. Alteration minerals are sometimes 

obscured by, or may include, malachite, azurite, metamorphic 

chlorite, actinolite, epidote, albite, quartz, zeolites, and 

secondary dolomite. The depositional environment consists of 

subaerial basalt overlain by mixed shallow marine and 

nearshore carbonate sedimentary rocks, including sabkha-

facies carbonate rocks.



Deposits Related to Surficial Processes: Placer, 

Paleoplacer, and Laterite Deposits



        Placer deposits are classified primarily by metals and 

secondarily by sedimentary processes. The principal 

sedimentary processes are fluvial and glaciofluvial, 

shoreline, and eluvial or residual. Fluvial and 

glaciofluvial deposits form where river velocities lessen at 

hydraulic flexures, on the inside of meanders, below rapids 

and falls, and beneath boulders. Shoreline deposits form in 

areas of strandline accumulations that are caused by 

shoreline drift, beach storms, wind, and wave actions. 

Eluvial and residual deposits form by the mechanical and 

(or) chemical disintegration of bedrock in the general 

absence of the concentrating force of water.



Placer and paleoplacer Au (W.E. Yeend in Cox and Singer, 

1986)



        This deposit type consists of elemental gold as grains 

and rarely as nuggets in gravel, sand, silt, and clay, and 

their consolidated equivalents in alluvial, beach, eolian, 

and rarely in glacial deposits. The major deposit minerals 

are gold, sometimes with attached quartz, magnetite or 

ilmenite. The depositional environment is high-energy 

alluvial where gradients flatten and river velocities lessen 

as at the inside of meanders, below rapids and falls, 

beneath boulders, and in shoreline areas where the winnowing 

action of surf causes gold concentrations found in raised, 

present, or submerged beaches.



Placer Sn (Nokleberg and others, 1987)



        This deposit type consists of mainly cassiterite and 

elemental gold in grains in gravel, sand, silt, and clay, 

and their consolidated equivalents, mainly in alluvial 

deposits. The depositional environment is similar to that of 

placer Au deposits.



Placer PGE-Au (W.E. Yeend and N.J Page in Cox and Singer, 

1986)



        This deposit type consists of PGE minerals and alloys in 

grains in gravel, sand, silt, and clay, and their 

consolidated equivalents in alluvial, beach, eolian, and 

rarely in glacial deposits. In some areas, placer Au and 

placer PGE deposits occur together. The major deposit 

minerals are Pt-group alloys, Os-Ir alloys, magnetite, 

chromite, and ilmenite. The depositional environment is 

high-energy alluvial where gradients flatten and river 

velocities lessen as at the inside of meanders, below rapids 

and falls, beneath boulders, and in shoreline areas where 

the winnowing action of surf causes PGE and gold 

concentrations in raised, present, or submerged beaches.



Placer Ti (E.R. Force in Cox and Singer, 1986)



        This deposit type consists of ilmenite and other heavy 

minerals concentrated by beach processes and enriched by 

weathering. The hosting sediment types are medium- to fine-

grained sand in dune, beach, and inlet deposits. The 

depositional environment is a stable coastal region 

receiving sediment from bedrock regions. The major deposit 

minerals are low-Fe ilmenite, sometimes with rutile, zircon, 

and gold.



CLASSIFICATION OF LODE MINERAL DEPOSITS INTO METALLOGENIC 

BELTS



        This study classifies the lode mineral deposits of the 

Russian Far East, Alaska, and the Canadian Cordillera into 

metallogenic belts according to known significant mineral 

deposits, mineral deposit types, tectonic setting, and 

tectonic environment. This classification uses the following 

subdivision of deposits, based on tectonic setting: (1) pre-

accretionary deposits that formed early in the geologic 

history of each tectono-stratigraphic terrane and are 

thereby unique to each terrane; (2) (syn)accretionary 

deposits that formed during periods of major structural 

juxtaposition, regional deformation, and penetrative 

deformation that generally occurred during collision of now 

adjacent terranes; and (3) post-accretionary deposits that 

formed late in the geologic history of groups of terranes, 

and generally occur in two or more adjacent terranes. The 

metallogenic belts defined in this report are based on the 

significant deposits of the region which were selected to be 

representative of the metallogeny of the region. Other, less 

well-defined metallogenic belts may be defined for larger 

groups of relatively small mineral deposits.



        The major tectonic environments used to characterize 

metallogenic belts in this study are: (1) accretionary 

wedge; (2) continental-margin arc; (3) continental rift; (4) 

island arc; (5) metamorphic; (6) oceanic crust, seamount, 

and ophiolite; and (7) subduction zone. Definitions of these 

environments are provided above. The tectonic 

classifications of lode mineral deposits is currently a 

topic of considerable debate (Sawkins, 1990); however 

classification of lode mineral deposits by mineral deposit 

types and tectonic environment can be extremely useful. 

These classifications can be used for regional mineral 

exploration and assessment, for research on the critical or 

distinguishing characteristics of metallogenic belts, and 

for synthesizing of metallogenic and tectonic models. To 

describe the metallogenic belts of the region, the 

significant lode deposits are classified both according to 

mineral deposit type and tectonic environment.





EXPLANATION OF TABLES ON SIGNIFICANT LODE DEPOSITS AND 

PLACER DISTRICTS

Tabular Descriptions for Sizes of Lode Deposits

        Size categories for lode mineral deposits, adapted from 

Guild (1981), are listed below. These size categories define 

the terms world class, large, medium, and small. These size 

categories are used mainly in the parts of Table 1 on the 

lode deposits in the Russian Far East where specific tonnage 

and grade data are not yet available. The small category may 

include occurrences of unknown size. Units are metric tons 

of metal or mineral contained, unless otherwise specified.   



NOTE: For the following and other tables in this text, the

reader is referred to the corresponding word-processing

files, either RFENATAB.DOC (Word 6.0 for Windows or Macintosh)

or RFENATAB.MCW (Word 5.1 for Macintosh).