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Chapter 5
Introduction
This article presents an overview of the regional geol- ogy, tectonics, and metallogenesis of Northeast Asia for the Neoproterozoic through Silurian. The major purposes are to provide a detailed summary of these features for readers who are unfamiliar with Northeast Asia. Several parts of this book on Northeast Asia provide background information. An overview of the regional geology, metallogenesis, tectonics, of the region, and other materials, such as employed geologic time scale and standard geologic definitions, are provided in chapter 1. The methodology for the metallogenic and tectonic analysis of this region is provided in Chapter 2. Descriptions of mineral deposit models are provided in Chapter 3. Addi- tional information on project publications, descriptions of major geologic units, and summaries of metallogenic belts are provided in appendixes A-C.
Compilations Employed for Synthesis, Project
Area, and Previous Study
The compilation of regional geology and metallogen- esis in this introduction is based on publications of the major international collaborative studies of the metallogenesis and tectonics of Northeast Asia that were led by the U.S. Geologi- cal Survey (USGS). These studies have produced two broad types of publications. One type is a series of regional geologic,
Neoproterozoic through Silurian Metallogenesis and
Tectonics of Northeast Asia
By Nikolai A. Berzin^1 , Elimir G. Distanov^1 , Onongyn Tomurtogoo^2 , Andrei V. Prokopiev^3 ,
Vladimir F. Timofeev^3 , and Warren J. Nokleberg^4
(^1) Russian Academy of Sciences, Novosibirsk. (^2) Mongolian Academy of Sciences, Ulaanbaatar. (^3) Russian Academy of Sciences, Yakutsk. (^4) U.S. Geological Survey, Menlo Park, Calif. mineral-deposit, and metallogenic-belt maps and companion descriptions for the regions. Examples of major publications of this type are Obolenskiy and others (2003, 2004), Parfenov and others (2003, 2004a,b), Nokleberg and others (2004, 2005), Rodionov and others (2004), and Naumova and others (2006). The other type is a suite of metallogenic and tectonic analyses of these same regions. Examples of major publica- tions of this type are Rodionov and others (2004), Nokleberg and others (2000, 2004), and Naumova and others (2006). Detailed descriptions of lode deposits are available in Ariun- bileg and others (2003). For more detail than presented in this chapter, refer to the detailed descriptions of geologic units and metallogenic belts in the above publications. The Northeast Asia project area consists of eastern Russia (most of Siberia and most of the Russian Far East), Mongolia, Northern China, South Korea, Japan, and adjacent offshore areas (fig. 1). This area is approximately bounded by 30 to 82° N. latitude and 75 to 144° E. longitude. The major participat- ing agencies are the Russian Academy of Sciences; Academy of Sciences of the Sakha Republic (Yakutia); VNIIOkean- geologia and Ministry of Natural Resources of the Russian Federation; Mongolian Academy of Sciences; Mongolian University of Science and Technology; Mongolian National University; Jilin University; Changchun; China; the China Geological Survey; the Korea Institute of Geosciences and Mineral Resources; the Geological Survey of Japan/AIST; University of Texas Arlington; and the USGS. The Northeast Asia project extends and is built on data and interpretations from a previous project on the Major Mineral Deposits, Metallogenesis, and Tectonics of the Russian Far East, Alaska, and the Canadian Cordillera that was conducted by the U S G S, the Russian Academy of Sciences, the Alaska Division of Geological and Geophysical Surveys, and the Geological Sur- vey of Canada. A summary of the major products of this project is contained online at: http://pubs.usgs.gov/of/2006/1150/ PROJMAT/RFE-Ak-Can_Cord_Proj_Pamph.pdf and in appendix A. Metallogenesis and Tectonics of Northeast Asia Edited by Warren J. Nokleberg U.S. Geological Survey Professional Paper 1765
5-2 Metallogenesis and Tectonics of Northeast Asia Lake Baikal VLADIVOSTOK KHABAROVSK CHANGCHUN TOKYO BEIJING SEOUL IRKUTSK ULAANBAATAR YAKUTSK NOVOSIBIRSK 68 76 82 44 52 96 (^108 ) 132 144 36 75 84 60 International boundaries for onshore area are approximate and do not indicate endorsement by participating countries. 0 500 1,000 km M O N G O L I A C H I N A R U S S I A NORTH-CENTRAL CHINA NORTHWEST CHINA NORTHEAST CHINA KOREAN PENINSULA J A P A N Pacific Ocean Kara Sea Laptev Sea Y a k u t i a S i b e r i a S o u t h e a s t e r n S i b e r i a a n d T r a n s b a i k a l i a R u s s i a n F a r E a s t Figure 1. Regional summary geographic map for Northeast Asia showing major regions and countries. Major Geologic Units The major Neoproterozoic (Late Riphean through Vendian) through Silurian geologic and tectonic units of Northeast Asia are cratonal margin units, sedimentary basins formed on craton and cratonal margins and accreted terranes and superterranes (fig. 2, table 1). Short descriptions of map units are given in appendix B. Summary descriptions of the major units are provided in descriptions of metallogenic belts (below), and detailed descriptions of geologic units are provided by Nokleberg and others (2000, 2004), and Parfenov and others (2004b).
Major Craton Margins and Craton-Margin
Terranes
The Archean through Proterozoic backstop or core units for the region of Northeast Asia are the North Asian craton and overlying Phanerozoic units, various cratonal margin units [Baikal-Patom, East Angara, South Taimyr, and Verkhoyansk terranes (fold- and thrust-belts)],and the Sino-Korean craton (fig. 2, appendix C). The Baikal-Patom cratonal margin (BP) consists of a fault-bounded basin containing Riphean carbonate and terrig- enous sedimentary rock, and younger Vendian and Cambrian
5-4 Metallogenesis and Tectonics of Northeast Asia GY GY GY NAC SKC HS HS BJ HS KR ST Bering Sea Pacific Ocean Laptev Sea CS VK VK KOM SA (^) CH oc nb, ol uy, ma oc, us oc, us oc, us oc ol KOR VR OH PA WK OK OK PA WK OK EP WS CS tp EA BP AL AL AL YT YT YT YT YT AR AR TM SM AB SM AB SL SL JA SL WD BJ BJ BJ BJ BD HS HS ea ji sm sm at at ko nm gh lg nr se se ha, mt se ss ss ss tb tb ke us uo sv tr MO CS SH JT JT NN ES SH ja ja ib Sea of Okhotsk Lake Baikal East-Siberian Sea kk MO MO P A C I F I C P L A T E ES ES MO 156 168 188 0 1,000 2,000 km Figure 2. Northeast Asia summary geodynamics map. Map is derived from (1) a Generalized Northeast Asia Geodynamics Map at 10 million scale (Parfenov and others, 2004); (2) a more detailed Northeast Asia Geodynamics Map at 5 million scale (Parfenov and others, 2003); and (3) the western part of a Circum-North Pacific tectono-stratigraphic terrane map at 10 million scale (Nokleberg and others, 1997). Map shows locations major geologic and tectonic units including cratons, cratonal margins; cratonal terranes and superterranes; tectonic collages; overlap and transform continental-margin arcs; island arcs, and sea and ocean units. Map and Explanation. Refer to table 1 and text for unit descriptions.
5. Neoproterozoic through Silurian Metallogenesis and Tectonics of Northeast Asia 5-
EXPLANATION
Cratons and Cratonal Margins Cratons: NAC - North Asian (Archean and Proterozoic); SKC - Sino-Korean (Archean and Proterozoic) Cratonal Margin: BP - Baikal-Patom (Riphean through Cambrian and older basement; EA - East Angara (Riphean and older basement; ST - South Taimyr (Ordovician through Jurassic); VR - Verkhoyansk (Devonian through Jurassic). Tectonic Collages Between the North Asian and Sino-Korean Cratons Tectonic Collages Along the Northern and Eastern Margins of North Asian and Sino-Korean Cratons Active Subduction Zones CS - Circum-Siberia (Proterozoic) YT - Yenisey-Transbaikal (Vendian through Early Ordovician) AL - Altay (Vendian to Ordovician) WD - Wundurmiao (Riphean through Ordovician) AB - Atasbogd ( ; SM - South Mongolia-Khingan (Ordovician through Carboniferous); WS - West Siberian (Ordovician through Carboniferous) Ordovician through Permian) MO - Mongol-Okhotsk (Devonian through Late Jurassic); SL - Solon (Carboniferous and Permian) CH - Chukotka (Paleozoic and Triassic) BD - Badzhal (Triassic through Early Cretaceous); PA - Penzhina-Anadyr (Late Jurassic and Cretaceous); HS - Honshu-Sikhote-Alin (Jurassic and Early Cretaceous); SA - South Anyui (Permian through Jurassic); VK - Verkhoyansk-Kolyma Paleozoic through Early Jurassic) KOR - Koryak (Late Jurassic through Paleocene; SH - Sakhalin-Hokkaido (Cretaceous); WK - West Kamchatka (Mid-Cretaceous through Early Tertiary) ES - East Sakhalin (Late Cretaceous and Early Tertiary); OK - Olyutorka-Kamchatka (Late Cretaceous to Paleocene) Cratonal terranes (Archean and Proterozoic): GY - Gyeonggi-Yeongnam; JA - Jiaonan; OH - Okhotsk Late Proterozoic and Cambrian superterranes: AR - Argun-Idermeg; TM - Tuva-Mongolia Archean through Permian superterranes: BJ - Bureya-Jiamusi; KR - Kara Jurassic Superterrane: KOM - Kolyma-Omolon (Archean through Jurassic) Oceanic crust Surficial deposits Pelagic and Oceanic Rocks Cratonal Terranes and Superterranes Overlap Continental-Margin Arcs and Igneous Belts Plume-Related Igneous Province Active Arcs
- Altay arc (Devonian and early Carboniferous, 381 to 290 Ma) East Sikhote-Alin arc (Late Cretaceous through early Tertiary, 96-65 Ma)
- arc
- Hangay arc ( arc arc
- Lugyngol arc (Permian and Triassic, 295 to 250 Ma)
- Norovlin arc (Devonian and Early Carboniferous, 410 to 255 Ma)
- Okhotsk-Chukotka arc (Late Cretaceous and early Tertiary, 96 to 53 Ma)
- arc
- Selenga arc (
- South Mongolian arc (Carboniferous through Triassic, 320 to 203 Ma)
- South Siberian arc (Devonian)
- South Verkhoyansk granite belt (Late Jurassic through mid-Cretaceous, 157 to 93 Ma)
- Transverse granite belt (Early Cretaceous, 134 to 124 Ma)
- arc
- Uda-Murgal and Stanovoy arc ( arc (Late Jurassic and Early Cretaceous, 154 to 120 Ma)
- Tungus Plateau igneous province - (Late Permian and Early Triassic, 245 Ma)
- Izu-Bonin (late Cenozoic, 20 to 0 Ma)
- Japan (late Cenozoic, 23 to 0 Ma)
- Kuril-Kamchatka (late Cenozoic, 11 to 0 Ma) at ea - gh ha lg nr oc ol se sm ss sv tr uo us ib ja kk Gobi-Khankaisk-Daxing'anling (Permian, 295 to 250 Ma) Late Carboniferous and Early Permian, 320 to 272 Ma)
- Jihei (Permian, 295 to 250 Ma)
- Khingan (Early and mid-Cretaceous) Main granite belt (Late Jurassic, 144 to 134 Ma)
- Northern granite belt (Early Cretaceous, 138 to 120 Ma) North Margin (Late Carboniferous and Permian, 320 to 272 Ma) Oloy (Late Jurassic, 154 to135 Ma) Permian through Jurassic, 295 to135 Ma) Umlekan-Ogodzhin (Cretaceous, 135 to 65 Ma) Jurassic and Early Cretaceous, 203 to 96 Ma)
- Uyandina-Yasachnaya ji ko ma - nb nm - uy Transpressional Arcs
- Kema (Mid-Cretaceous)
- Mongol-Transbaikal (
- South Siberian
ke mt ss tb Late Triassic through Early Cretaceous, 230 to 96 Ma) (Early Devonian, 415 to 400 Ma) Transbaikalian-Daxinganling (Middle Jurassic through Early Cretaceous,175 to 96 Ma) EP - East Kamchatka Peninsular (Mainly Paleocene) JT- Japan Trench (including Kuril-Kamchatka trench) (Miocene through Holocene; NN - Nankai (Miocene through Holocene) Devonian aulacogen Riphean aulacogen Modern rift system (Gakkel Ridge) Metallogenic belt Thrust Strike-slip fault Fault Contact Symbols, Faults, and Contacts Overlap-continental-margin arc Transform-continental-margin arc Active subduction zone OS tp Figure 2.— Continued.
5. Neoproterozoic through Silurian Metallogenesis and Tectonics of Northeast Asia 5- Name of unit.^ Map Symbol Type of Unit (Craton, Terrane, Overlap Asseblage) Age range Tectonic Environment Tectonic Linkage TECTONIC COLLAGES Altai. AL Collage Vendian through Ordovician Mainly Island arc and subduction zone C onsists of the Vendian through Early Ordovician Salair^ island-arc and various fragments of arc-related turbidite^ terranes, subduction-zone terranes, metamorphic terranes^ derived from arc-related units, thick Cambrian and Ordovi
cian overlap turbidite units that formed on a continental slope and rise, and fragments of originally adjacent oceanic terranes. Collage interpreted as an island-arc system that was active near the southwest margin (present-day coordi
nates) of the North Asian Craton and Margin and previ
ously accreted terranes. Accreted in Late Silurian. Atasbogd. AB Collage Ordovician through Permian Composite Consists of: the Ordovician through Permian Waizunger- Baaran terrane, Devonian through Carboniferous Beitian
shan-Atasbogd terrane, and (3) Paleoproterozoic through Permian Tsagaan Uul-Guoershan continental-margin arc terrane. Collage is interpreted as a southwest continuation (present-day coordinates) of the South Mongolia-Khingan island arc that formed southwest and west (present-day coordinates) of the North Asian Craton and Margin and previously accreted terrane. Accreted in Late Carboniferous or Early Permian. Circum-Siberia. CS Collage Neoproterozoic Composite Consists of Baikal-Muya island arc, the Near Yenisey Ridge island arc, and the Zavhan continental-margin arc, all of Neoproterozoic age, and small fragments of cratonal and metamorphic terranes of Archean and Proterozoic age. The three separate Neoproterozoic island-arc systems formed south (present-day coordinates) of the North Asian Craton and Margin. Accreted in Neoproterozoic South Mongolia-Kh
ingan. SM Collage Ordovician through Carboniferous Island arc and sub
duction zone Consists of the South Mongolia-Khingan arc and tectonically linked subduction-zone terranes. The collage is interpreted as a major island-arc system that formed southwest and west (present-day coordinates) of the North Asian Craton and Margin and previously accreted terranes. Collage was separated from the North Asian Craton by a large back-arc basin. accreted in Late Carboniferous or Early Permian. Table 1. Summary of major Neoproterozoic through Silurian geologic units and characteristics for Northeast Asia (Russian Far East, Yakutia, Siberia, Transbaikalia, Northeastern China, Mongolia, South Korea, and Japan).—Continued [Major units are listed from west to east, progressing from north to south. Units arranged in alphabetical order of map symbol in each major section on figure 2]
5-8 Metallogenesis and Tectonics of Northeast Asia Table 1. Summary of major Neoproterozoic through Silurian geologic units and characteristics for Northeast Asia (Russian Far East, Yakutia, Siberia, Transbaikalia, Northeastern China, Mongolia, South Korea, and Japan).—Continued [Major units are listed from west to east, progressing from north to south. Units arranged in alphabetical order of map symbol in each major section on figure 2] Name of unit.^ Map Symbol Type of Unit (Craton, Terrane, Overlap Asseblage) Age range Tectonic Environment Tectonic Linkage TECTONIC COLLAGES Wundurmiao. WD Collage Mesoproterozoic through Silurian Island arc and sub
- duction zone Consists of Late Ordovician through Silurian Laoling island- arc terrane, Mesoproterozoic through Middle Ordovician Wundurmiao subduction-zone terrane, and Neoproterozoic Seluohe subduction-zone terrane. The collage is interpreted as the Laoling island-arc system that formed near Sino- Korean Craton. Both the island-arc system and craton were widely separated from North Asian Craton in the early Paleozoic. Accreted in Late Silurian. West Siberian. WS Collage Ordovician through Carboniferous Island arc and sub - duction zone Consists of the Late Silurian through Early Carboniferous Rudny Altai island-arc, and the tectonically linked Ordovi - cian through Early Carboniferous Kalba-Narim subduction- zone terrane. Collage is a northwest continuation (present- day coordinates) of the South Mongolia-Khingan collage. Accreted in Late Carboniferous or Early Permian. Yenisey-Transbaikal. YT Collage Vendian through De - vonian Mainly Island arc and subduction zone Consists of the Vendian through Middle Cambrian Kuznetsk- Tannuola, Dzhida - Lake island-arc terranes, tectonically linked back-arc basins, and now tectonically eroded sub - duction-zone terranes. The collage is interpreted as a linear array of island-arc systems that formed south (present-day coordinates) of the North Asian Craton and Margin and previously accreted terranes. The eastern part of the collage also includes the West Stanovoy metamorphosed terrane that may be a displaced fragment of the North Asian Craton or of another craton. Accreted in Vendian through Early Ordovician.
5-10 Metallogenesis and Tectonics of Northeast Asia North Asian craton or the Yenisey-Transbaikal and Circum- Siberia collages. These favorable geologic environments consisted of regional metamorphism and hydrothermal alter- ation that were associated with accretion of terranes to the North Asian cratonal margin. The Bokson-Kitoiskiy metal- logenic belt also contains serpentine-hosted asbestos deposits that are interpreted as having formed in the same tectonic environment. The Prisayanskiy belt is hosted in terranes derived from the North Asian craton and contains REE car- bonatite, and mafic-ultramafic related Ti-Fe deposits that are interpreted as having formed in Neoproterozoic magmatic events. The Jixi metallogenic belt contains minor Homestake Au deposits for which the tectonic origin is unclear. Major Neoproterozoic (1,000 to 540 Ma) Metallogenic Belts and Host Units The major Neoproterozoic metallogenic belts are the Angara-Pit, Baikalo-Muiskiy, Bodaibinskiy, Bokson-Kitoiskiy, Central-Yenisei, Hovsgol, Jixi, Kyllakh, Lake, Pribaikalskiy, Prisayanskiy, and Vorogovsko-Angarsk belts (fig. 3, appendix C).
Angara-Pit Metallogenic Belt of Sedimentary
Hematite and Volcanogenic-Sedimentary Fe
Deposits (Belt AP) (Yenisei Ridge, North-Asian
Craton Margin, Russia)
This Upper Riphean metallogenic belt is hosted in the North Asian cratonal margin (East Angara fold- and thrust- belt) and occurs in the southeastern part of the Yenisei Ridge. The belt forms a band along the east wing of the Central anticlinorium from the Angara River to the north to the Gorbilok River to the south, and is up to 100 km long. The belt contains three large chlorite-hematite deposits at Nizhne-Angarskoye, Ishimbinskoye, and Udorongovskoye, and numerous smaller occurrences. The deposits occur in clastic sedimentary rock of the late Riphean Nizhneangarsk. Each deposit consists of several (about 7 to 36) ore layers that vary from 2 to 16 m thick (ranging up to 30 m), have a total thickness of as much as 50 m, and are 0.3 to 14 km long. All deposits exhibit similar geological structure, min- eral composition, and quality of ore minerals. Ore layers and lenses are hosted in clastic and clastic-chemogenous sedi- mentary rocks, mainly hematite gritstone and conglomerate, hematite sandstone, and sandy hematite-chlorite siltstone. Host rocks and deposits are metamorphosed to phyllite (Matrosov and Shaposhnikov, 1988). The major deposit is at Nizhne-Angarskoye. The main references on the geology and metallogenesis of the belt are Yudin (1968), Brovkov and others (1985), and Matrosov and Shaposhnikov (1988).
Nizhne-Angarskoye Sedimentary Hematite Fe
Deposit
This deposit (Yudin, 1968; Brovkov and others, 1985) consists of layered hematite hosted in late Riphean argil- lite, siltsone, and sandstone. The Fe horizon is 45 to 180 m thick and occurs in 36 separate deposits that range up to 29 m thick, extend up to 15 km along strike, and range to 650 m depth. Fe layers are intercalated with sedimentary rocks that range from to 2 to 15 m thick. Ore layers consist of hema- tite, sandy-hematite, argillaceous chlorite hematite gritstone, hematite-siderite. Main ore minerals are hydrogoethite, hema- tite, and goethite with lesser siderite, magnetite, and pyrite. Gangue minerals are quartz, leptochlorite, clays, and sericite. The deposit contains 0.03 percent S and 0.08 percent P. The deposit is large with reserves of 1,200 million tonnes grading 40.4 percent Fe.
Origin and Tectonic Controls for Angara-Pit
Metallogenic Belt
The belt is interpreted as having formed during a preoro- genic stage of the Yenisei pericratonal subsidence in a back- arc (interland) sedimentary basin. Lithological-facial control of distribution of sedimentary hematite ores occurred. The paleodelta setting of formation of Fe ores is indicated by struc- tural, mineralogical, and geochemical features of host rocks (Yudin, 1968). A possible source of clastic ore minerals was residual Fe-rich weathering crust (Brovkov and others, 1985).
Baikalo-Muiskiy Metallogenic Belt of
Volcanogenic-Hydrothermal-Sedimentary
Massive Sulfide Pb-Zn (±Cu), Polymetallic (Pb,
Zn, Ag) Carbonate-Hosted Metasomatite, and
Serpentine-Hosted Asbestos Deposits (Belt BM)
(Russia, Northern Transbaikalia)
This Neoproterozoic metallogenic belt occurs in the Baikal-Muya island-arc terrane, the Muya metamorphic ter- rane, and part of the Olokit-Delunur craton-margin rift terrane. The major deposits are at Kholodninskoye, Lugovoye, and Molodezhnoye. The belt occurs along the northern periphery of the Vitim highland (northeastern coast of Lake Baikal) and extends from Lake Baikal to Vitim River. The belt is 500 km long and 120 km wide. The lower part of the Baikal-Muya island-arc terrane consist of tectonic slabs of ophiolite of various ages with hemipelagic sedimentary rock (Lower Kelyansky suite); and a middle Riphean island-arc complex basalt, andesite, and plagiorhyolite (Verkhne Kelyansky suite), and gabbro and pla- giogranite intrusions. The island-arc rocks are metamorphosed to greenschist facies (Bulgatov and Gordienko, 1999; Bozhko and others, 1999).
5. Neoproterozoic through Silurian Metallogenesis and Tectonics of Northeast Asia 5- Figure 3. Generalized map of major Neoproterozoic metallogenic belts and major geologic units for Northeast Asia. Refer to text and appendix C for summary descriptions of belts. Refer to figure 2 and table 1 for explanation of geologic units. Metallogenic belt outlines adapted from Obolenskiy and others (2003, 2004) and Parfenov and others (2003, 2004). Metallogenic belts for area east of 144º E (eastern boundary of Northeast Asia project area) are described and interpreted by Nokleberg and others (2003). The Muya terrane consists of the metamorphic Kindikan- sky, Ileirsky, and Lunkutsky suites. The Olokit-Delunuran craton-margin rift terrane con- sists of Riphean volcaniclastic and sedimentary rocks of the Olokit series with abundant interbedded tholeiitic basalt and rhyolite, volcanogenic siliceous sedimentary rock and tuff, and late Riphean carbonaceous, clastic, carbonate sedimentary rock of the Dovyren series. All units are metamorphosed to amphibolite facies and folded. The top displays subhorizon- tally lying postaccretionary sedimentary rock of intermontane basins (basalt, rhyodacite and molasse of the Padrinsky series late Riphean). The suture complexes are collisional late Paleozoic gran- itoids of the Barguzin-Vitim belt. The belt contains a group of depos- its and large ore occurrences: Kholodninskoe GY GY GY NAC SKC HS HS BJ HS KR ST Bering Sea Pacific Ocean Laptev Sea CS VK VK KOM SA (^) CH oc nb, ol uy, ma oc, us oc, us oc, us oc ol KOR VR OH PA WK OK OK PA WK OK EP WS CS tp EA BP AL AL AL YT YT YT YT YT AR AR TM SM AB SM AB SL SL SL JA WD BJ BJ BJ BJ BD HS HS ea ji sm sm at at ko nm gh lg nr se se ha,mt se ss ss ss tb tb ke us uo sv tr MO CS SH JT JT NN ES SH ja ja ib Sea of Okhotsk Lake Baikal East-Siberian Sea kk MO MO P A C I F I C P L A T E ES ES MO 156 168 188 0 1,000 2,000 km BM BK AP CY VA KY PR PB LA HO JX
5. Neoproterozoic through Silurian Metallogenesis and Tectonics of Northeast Asia 5- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = (^) = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =^ = = = = = = = = = =^ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = == = = = = = = = = = = = == = = = = = = = = = (^) = == = = = = = = = = = = (^) = = = = = = = = = = = = = = = = = = = = ^ ^ ^ ^ ^ ^ ^ = == = = = = = = = = = = = == = = = = = = =
^ ^ ^ ^ ^ ^ ^ ^ = = = = = = = = == = = = = = = = = = = = = = = = ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^^ ^ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~ ~^ ~ ~ ~ ~ ~ ~ == ~ ~ == _ _ ^ (^) ^^ SE NW (^0 50 100) 150 m PR PR 2 2 PR PR PR PR PR PR PR 2 2 2 2 2 2 2 Cu Cu Cu Cu Cu = = === Graphite-carbonate-micaceous schist (layered aleuropelite) (Neoproterozoic) Graphite-quartz-carbonate-micaceous schist (layered calcareous aleuropelite) (Neoproterozoic) Graphite-carbonate-quartz-micaceous schist with thin beds of quartz sandstone (Neoproterozoic) Light limestone (Neoproterozoic) Garnet-biotite-amphibole porphyroblastic rock (Neoproterozoic) Orthoamphibolite (Neoproterozoic) Pyrite base metal sulfides Cu-sulfide ore bodies Quartz-muscovite metasomatite (Neoproterozoic) Fault Graphite limey dolomite (Neoproterozoic) Figure 4. Schematic cross section of Kholodninskoe (volcanogenic-hydrothermal-sedimentary massive Pb-Zn sulfide deposit, Baikalo-Muiskiy metallogenic belt. Adapted from Distanov and others (1982).
5-14 Metallogenesis and Tectonics of Northeast Asia ankerite, dolomite, calcite), and pseudomorphs of limonite after pyrite. Also occurring are rare muscovite, chlorite, galena, sphalerite, chalcopyrite, arsenopyrite, and pyrrho- tite. Gold is intergrown with pyrrhotite, chalcopyrite, and galena. Pt grade increases with sulfide content. The Sukhoy Log deposit occurs in the central part of a 3rd order anticline with sublatitudinal strike. The anticline core contains Neo- proterozoic black shale alternating with limestone and quartz sandstone that are metamorphosed to greenschist facies. The deposit is large and has an average Au grade of 2.8 to 3.6 ppm and a similar Pt grade.
Origin and Tectonic Controls for Bodaibinskiy
Metallogenic Belt
The major deposits in the belt are interpreted as having formed in two stages. (1) In the Riphean and early Paleozoic, Au accumulated during sedimentation with later metamor- phism and hydrothermal activity (Buryak, 1982). These events C^50 10 18 7
__ __ (^) __ __ __ (^) __ (^) __ __ (^) __ __ (^) __ __ (^) __ __ (^) __
__ __ __ (^) __
__ (^) __ __ (^) __ (^) __
__ (^) __ __ (^) __ ~ ~ ~ (^0 80) 160 m Zone of intense pyrite alteration Sedimentary and metamorphic units, Patom Series (Neoproterozoic) Khomolkho Suite (Neoproterozoic) Siltstone and quartz-feldspar-mica sandstone Carbonaceous phyllite-siltstone Carbonaceous quartz-sericite silty shale, intensely sheared Quartz vein Halo of gold-quartz-sulfides Axial line of Sukhoy Log anticline Fault Plunging fold hinge Strike and dip of bedding a, Normal b, Inverted Carbonaceous limestone, calcareous siltstone, and sandstone (Imnyakhsky Suite) a b Contact formed scattered Au-sulfide deposits. (2) In the middle to late Paleozoic, postcollisional intrusion of granite and leucogranite along with hydrothermal activity formed commercial Au- quartz-sulfide deposits (Konovalov, 1985). The age of Au from deposit Sukhoy Log is about 320 Ma. A subsequent magmatic and hydrothermal event was intrusion of the middle and late Paleozoic Kadali-Butuinsky dike complex (Rundquist and oth- ers, 1992). This event formed Au-Ag-sulfosalt deposits. The belt is promising for discovery of large Au deposits.
Bokson-Kitoiskiy Metallogenic Belt of
Sedimentary Bauxite, Magmatic Nepheline,
Serpentine-hosted Asbestos, and Au in Shear-
Zone and Quartz-Vein Deposits (Belt B-K)
(Russia, East Sayan)
This Neoproterozoic through Silurian metallogenic belt is related to veins in plutons intruding in the Belaya-Kitoy Figure 5. Generalized geologic map of Sukhoy Log Au in black shale deposit, Bodaibinskiy metallogenic belt. Adapted from Konovalov (1985).
5-16 Metallogenesis and Tectonics of Northeast Asia ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ X X
__ __ __ __ __ __ __ __
__
__ __
-^ -
~ ~ ~ X X X X X X X X X X
X X X X X X X X X X X X X X X X X X X X X X X X X
(^) -
1, 2, 2, 2,267 m ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ _ _
_ _ _ _ _ a b Ilchir Suite - Green and black shale, tuffaceous shale, and tuffaceous sandstone (Neoproterozoic), with local limestone and serpentinite olistolith Irkutnaya (Mongoshinskaya) Suite - Marble and limestone with interlayered black shale and quartzite (Neoproterozoic) Gargansky Metamorphic Complex (Archean and Paleoproterozoic) Sumsunursky Complex - Plagiogranite and granodiorite (Paleoproterozoic) Diorite and granodiorite (Devonian and Carboniferous) Granitized volcanic and sedimentary rock (Archean) Cataclastic zones a,Mylonite b,Shear Ore body Major shear Contact Figure 6. Schematic cross section of Zun-Kholba Au in shear-zone and quartz-vein deposit, Bokson-Kitoiskiy metallogenic belt. Adapted from Mironov and others (1995).6. Schematic cross section of Zun-Kholba Au in shear-zone and quartz-vein deposit, Bokson-Kitoiskiy metallogenic belt. Adapted from Mironov and others (1995).
5. Neoproterozoic through Silurian Metallogenesis and Tectonics of Northeast Asia 5- rock. High-grade asbestos occurs in two tectonic zones that cut the massif and vary from 100 to 400 m thick. Asbestos is a large network type with veinlets ranging from 20-30 mm thick (locally up to 70 mm), cutting in various directions, and occur- ring about 1 to 2 m apart. The ore minerals are chrysotile-asbes- tos, bastite, serpentine, ophite, magnetite, talc, chromite, brucite, antigorite, carbonates, pyroxene, and olivine. Asbestos is silky, durable, and is useful for technological purposes. The deposit is small and has an average grade of 2.5 percent asbestos fibre and 0.08 to 0.25 percent textile grade asbestos.
Origin and Tectonic Controls for Bokson-Kitoiskiy
Metallogenic Belt
This belt is hosted in metamorphic, oceanic, accretionary wedge, and tonalite-trondhjemite-gneiss terranes that under- went Cambrian through Silurian metamorphism, hydrothermal alteration, and plutonic intrusion. A younger suture complex is the subduction-related Sumsunur complex tonalite with a U-Pb and Rb-Sr isotopic age of 790 Ma. The deposits in the belt are interpreted as having formed in multiple events.
Central Yenisei Metallogenic Belt of Au in
Black Shale, Au in Shear-Zone and Quartz-Vein,
and Clastic-Sediment-Hosted Sb-Au Deposits
(Belt CY) (Yenisei Ridge, North-Asian Craton
Margin, Russia)
This Late Neoproterozoic metallogenic belt is hosted in the passive continental margin of the West Angara terrane and is related to regional metamorphism and granitoid magma- tism. The belt extends north-northwest along the axial zone of the Yenisei Ridge for 450 km and is 40 to 80 km wide in the central anticlinorium formed from Proterozoic rocks metamor- phosed to amphibolite and epidote-amphibolite facies (Paleo- proterozoic Teisk series), and to greenschist facies (Mesopro- terozoic Sukhopit series). The metallogenic belt is bounded by the Tatarsk fault zone to the west and by the Ishimbinsk fault zone to the east. The central anticlinorium is cut by a north- east-striking transform fault that controls the regional struc- ture, the occurrence of synorogenic and postorogenic granitoid intrusions, and the location of major districts. Au and Au-Sb deposits are predominant in the belt and occur mainly in three districts (from north to south) (1) Severo-Yenisei (Sovetskoye, Eldorado, Ajakhta, and others); (2) Verkhne-Enashiminsk (Olimpiada, Enashiminskoye); and (3) Partizansk (Udereis- koye, Razdolninskoye). Host rocks are mainly carbonate and clastic rock and black shale in the middle and lower parts of the middle Riphean Sukhopit series. Collisional batholithic granitoid S-type plutons of the Tataro-Ayakhtinsk complex (with an isotopic age of 850 Ma) are widespread (Kornev and others, 1996). The three main types of deposits are (1) Au-quartz-vein (Sovetskoye and others); (2) Au in black shale (Olimpiada and others); and (3) clastic-sediment-hosted Sb-Au (Udereiskoye, Razdolninskoye). Most deposits are polygenetic and formed during the middle to late Riphean and Vendian. The main references on the geology and metallogen- esis of the belt are Distanov and others (1975), Li and others (1984), Brovkov and others (1985), Kornev and others (1996), and Obolenskiy and others (1999).
Sovetskoye Au in Shear-Zone and Quartz-Vein
Deposit
This deposit (Petrovskaya, 1967; Petrov, 1974; Smirnov, 1978; Serdyuk, 1997; Simkin, 1997) consists of quartz-Au veins cutting Neoproterozoic phyllite that is intruded by small gabbro and diabase bodies, and Paleozoic syenite porphyry. The deposit occurs in a thick, conformable shear zone that is complicated by small-scale folds. The district containing the deposit extends up to 8 km along strike, ranges up to 650 m wide, and extends to 390 m depth. The deposit consists of subparallel, branching veins, veinlets, and lenses. Separate veinlets and veins vary from less than a cm to 10 to 20 cm thick. Veins contain mainly coarse-grained quartz and fragments of low-grade altered host rock. Gangue minerals are carbonate, sericite, albite, and chlorite. Ore minerals constitute about 5 percent and are pyrite, arsenopy- rite, lesser chalcopyrite, galena, sphalerite, pyrrhotite, and marcasite. Gold is fine-grained. Fineness of Au averages
- The deposits consist mainly of quartz, quartz-pyrite, quartz-arsenopyrite, and quartz-sulfide types. Quartz-sulfide type contains the most Au. Contact zones of deposits are more productive. Two types of hydrothermal wall-rock alterations are (1) combination of tourmaline, albite, seric- ite, and chlorite alteration; and (2) silica, sericite, chlorite, and sulfide alteration. Magmatic intrusive rocks occur 2 to 5 km to the northeast and consist of diabase and gabbro, and dikes of mica lamprophyre, syenite porphyry, and a slightly eroded granitoid pluton. A major magmatic chamber beneath the deposit is interpreted as the source of deposit-forming solutions (Brovkov and others, 1985). The deposit is medium size and has an average grade of 2.2 g/t Au.
Olympiada Au in Black Shale Deposit
This deposit (Li and others, 1990) (fig. 7) occurs in the central part of the Central-Yenisei metallogenic belt in the Verkhne-Enashiminsk district and consists of layered and saddle-shaped bodies of disseminated Au-sulfide in metaso- matite hosted in regionally metamorphosed Neoproterozoic carboniferous and clastic rock. The deposit occurs in a roof pendant above the large Neoproterozoic Chirimbinsk granitoid pluton. Host rocks are quartz-carbonate and micaceous schist with intercalated dolomite and carboniferous and quartz-mus- covite schist. Host rocks are hydrothermally altered to quartz- carbonate and mica, mica-carbonate and zoisite-quartz-mica metasomatite. Skarn locally occurs with metasomatite. The ore minerals are pyrrhotite, arsenopyrite, stibnite, berthierite,
5. Neoproterozoic through Silurian Metallogenesis and Tectonics of Northeast Asia 5- mineralized host rocks. Host rocks are slighly hydrothermally altered with formation of sericite, chlorite, silica, sulfides, carbonate, and tourmaline. The main ore minerals are quartz, stibnite, berthierite, arsenopyrite, pyrite, carbonate, sericite, native gold, sphalerite, galena, chalcopyrite, argentite, and fluorite. Distribution of Au in deposits is irregular. Higher Au concentrations occur in arsenopyrite. The deposit is interpreted as having formed in a complicated multistage process. Two younger mineral assemblages are quartz, arsenopyrite, and pyrite with Au, and quartz, berthierite, and stibnite with sparse Au. The deposit is medium size and has an average grade of 0.28 to 4.2 g/t Au.
Origin and Tectonic Controls for Central-Yenisei
Metallogenic Belt
The gold deposits of the belt are interpreted as having formed during collisional development of the late Riphean continental margin of the North Asian craton. Au initially occurring in black shale was subsequently concentrated and remobilized during collision-related metamorphism, granitoid intrusion, and hydrothermal activity (Obolenskiy and others, 1999). The belt occurs in the Sukhopit series that consists of sandstone and argillite formed in a marginal sea-shelf facies. Host rocks have anomalous Au, Sb, and W and are interpreted as possibl sources of ore (Berger, 1981). Au-quartz-vein deposits are associated with granitoid intrusions that form batholithic granitoids with deposits. Disseminated Au deposits in black shale (Olimpiada and others) are related to metaso- matite hosted in carbonate and clastic rocks in a roof pen- dant of a large granitoid pluton (Li and others, 1984). Sb-Au clastic-sediment-hosted, hydrothermal vein deposits occur in the Partizansk ore district in the southern part of the belt and are hosted in middle Riphean carbonaceous schist of the Uderei series (Distanov and others, 1975). K-Ar hydromica metasomatite isotopic ages for the youngest stage of deposits are 605 ± 30 Ma (Distanov and others, 1975) and 664 ± 36 Ma (Ovchinnikov and Voronovskiy, 1974). These ages are coeval with the Rb-Sr age of 601 ± 9 Ma for the Tatarsk granitoid pluton (Sobachenko and others, 1986). Recent interpretations for the origin of the belt consist of multistage polygenetic sedimentary, metamorphic, and hydrothermal origin of Au and Sb-Au deposits with primary accumulation of gold in black shale and subsequent concentration and remobilization during metamorphism and granitoid-related hydrothermal activity (Li, 1974a,b; Berger, 1981; Nekludov, 1995).
Damiao Metallogenic Belt of Mafic-Ultramafic
Related Ti-Fe (V) and Zoned Mafic-Ultramafic
Cr-PGE Deposits (Belt DM) (North China)
This Neoproterozoic metallogenic belt is hosted in mafic- ultramafic plutons intruding the West Liaoning-Hebei-Shanxi granulite-orthogneiss terrane in the Sino-Korean craton. The belt occurs in Mount Yanshan in the Damiao area of the east- ern Hebei Province. The belt trends east-west, is about 130 km long, and 50 km wide. The significant deposit is at Damiao. The main reference on the geology and metallogenesis of the belt is Cheng Yuqi and others (1994).
Damiao Mafic-Ultramafic Related Ti-Fe (V)
Deposit
This deposit (Cheng Yuqi and others, 1994) (fig. 8) consists of a number of lenses and veins. The larger deposits extend along strike up to 300 to 500 m, extend downdip to 500 m and range from several tens to a hundred meters thick. The deposits occur at the contact zone between anorthosite and gabbro, or in the dikes of anorthosite and gabbro. The ores are mainly massive Ti-magnetite, minor ilmenite, and sparse pyrite and chalcopyrite. Gangue minerals are chlorite, amphibole, plagioclase, and minor apatite. P 2 O 5 content is 0.07 percent. Also occurring is stockwork mainly in the gab- bro adjacent to the contacts with anorthosite. The ore miner- als are disseminated and are mainly Ti magnetite, ilmenite, plagioclase, augite, hypersthene, actinolite, chlorite, apatite, rutile, and sulphides. P 2 O 5 content is 0.59 to 0.93 percent, and Fe content is less than 20 percent. The host mafic intrusion intrudes Early Precambrian units along the northern margin of the Sino-Korea craton, and is controlled by east-west-trending regional faults. K-Ar isotopic ages for the anorthosite range from 992 to 604 Ma. The deposit is large with reserves of 130 thousand tonnes V 2 O 5 , grading 0.16 to 0.39 percent V 2 O 5 , reserves of 58 thousand tonnes TiO 2 , grading 7.17 percent TiO 2 , and 32 to 34 percent Fe.
Gaositai Zoned Mafic-Ultramafic Related Cr-PGE
Deposit
This deposit (Cheng, Yunchung and others, 1996) con- sists of a number of chromite bodies hosted in serpentinizied dunite and diopside pyroxenite that form part of an untramafic intrusion that is 9 km long and 1 km wide. The intrusion intrudes Early Precambrian metamorphic rock. The chromite bodies occur in veinlets and disseminations, and rare masses. The ore minerals grade into host rocks. The deposit occurs in the northern margin of the North China Platform in the Yanshan Mountains. Nearby are a number of similar small chromite deposits that occur along an east-west trend. The deposit is small and has reserves of 170,000 tonnes grading 14.12 percent Cr 2 O 3 and locally up to 40 percent Cr 2 O 3.
Origin and Tectonic Controls for Damiao
Metallogenic Belt
The belt is hosted in Neoproterozoic mafic-ultramafic plutons that intrude Archean crystalline rocks of West Liaoning-Hebei-Shanxi terrane. The plutons occur along
5-20 Metallogenesis and Tectonics of Northeast Asia Figure 8. Generalized geologic map and cross section of Damiao mafic-ultramafic related Ti-Fe (V) deposit, Damiao metallogenic belt. Adapted from Dong (1993). northwest-trending major faults along the northern margin of the Sino-Korean craton. The mafic and ultramafic intrusions have isotopic ages of 992 to 604 Ma. The plutons and deposits are interpreted as having formed during interplate magmatism related to a Neoproterozoic active continental margin along the north margin of the Sino-Korean craton.
Hovsgol Metallogenic Belt of Sedimentary
Phosphate, Sedimentary Mn, and Sedimentary
Fe-V Deposits (Belt HO) (Northern Mongolia)
This Vendian through Early Cambrian metallogenic belt occurs in the Huvsgol-Bokson sedimentary overlap assem--Bokson sedimentary overlap assem- blage. Sedimentary phosphate deposits and occurrences are mostly in the Vendian through Early Cambrian lower siliceous dolomite member of the Doodnuur or Kheseen Formations. Sedimentary Fe, sedimentary Mn, and sedi- mentary Fe-V occurrences are mainly above of the pro- ductive phosphate deposition in the Kheseen Formation, and also in clastic horizons of the Early Cambrian Khordil Formation (Ilyn, 1973). The metallogenic belt was first defined as a zone and as the Chubsugul phosphate basin by Ilyn (1973). Dejidmaa and others (1996) defined the belt as a complex metallogenic belt with sedimentary phosphorite, sedimentary Mn, Fe, Fe-Mn, and Fe-V deposits. The basin comprises approximately 30,000 km^2 , trends generally north-south, is approximately 300 km long, and ranges from a few tens to 120 km wide (Ilyn, 1973). The major deposits are the Urandosh, Uhaagol, Janhai, Ongilog nuur, Manhan A B 700 800 900 m Map Cross section Granodiorite(Triassic) Norite(Neoproterozoic) Anorthosite( Neoproteraloic) Monzonite Ore bodies Fault 0 400 800 m N Brecciated belt Syenite porphyry B A
