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By Sergey M. Rodionov1, Alexander A. Obolenskiy2


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Baydrag Metallogenic Belt of

Banded Iron Formation (BIF) Deposits

(Belt BD) (Central Mongolia)



This metallogenic belt occurs in the Paleoproterozoic Baydrag cratonal terrane and contains major BIF deposits in the Baidrag group. The northwest-striking metallogenic belt extends 400 km and ranges from 30 km to 50 km wide. BIF occurrences are are hosted in Paleoproterozoic gneiss, amphibolite, schist, marble, and quartzite in the Baydrag metamorphic complex. U-Pb isochron and Pb-Pb thermoisochron zircon ages for tonalite gneiss of the Baydrag metamorphic complex range from 2,650± 30 Ma to 2,800 Ma, and are 2,400 Ma for charnockite of the Bombogor intrusive complex (Zaitsev and others, 1990).

Baydragiin Gol III BIF Occurrence



This occurrence (Andreas, 1970) consists of layered silica-magnetite bodies hosted in a Paleoproterozoic unit of gneiss and quartzite. The bodies trend northwest are concordant with host gneiss. The length of the silica-magnetite bodies is approximately 4500 m, and thickness ranges from 10 to 100m. The main ore mineral is magnetite and the average grade is 25.7% Fe.

Origin and Tectonic Controls for

Baydrag Metallogenic Belt

The BIF deposits are hosted in Paleoproterozoic gneiss, amphibolite, crystalline schist marble and quartzite derived from a volcanic and clastic sedimentary rock basin. Host rocks are intruded by the Bombogor intrusive complex that is interpreted as forming in a continental margin arc.



REFERENCES: Andreas and others, 1970; Filippova and Bydrin, 1977; Bahteev, and Chijova, 1990; Zaitsev, Mitrofanov, and others, 1990; Tomurtogoo and others, 1999.

Yinshan Metallogenic Belt of

Banded Iron Formation (BIF,

Algoma Fe) Deposits

(Belt YS) (North-Central China)

This Late Paleoproterozoic metallogenic belt is related to marine volcaniclastic rocks overlapping the Archean Yinshain terrane. The belt occurs in the Yinshan Mountains in southwestern Inner Mongolia, is about 200 km long, is over 30 km wide, and strikes east-west. The deposits are hosted mainly in the late Paleoproterozoic Changcheng System. The significant deposit is at Shanhemen.


Sanheming Banded Iron Formation (BIF, Algoma Fe) Deposit

This deposit (Li Rangdao, 1993) consists of stratiform and layered Fe bodies in the Paleoproterozoic Sanminghe Group that is divided into six units, from lower to upper: lower amphibolite, lower magnetite quartzite, schist, middle amphibolite, upper magnetite quartzite, and upper amphibolite. Varied small dikes also occur. Host rocks are metamorphosed to amphibolite and greenschist facies. The deposits are stratiform and layered. Two Fe horizons occur. Deposit minerals are mainly magnetite, hematite, and limonite, and minor pyrite, tremolite, and biotite. Typical textures are idiomorphic-hypidiomorphic, xenomorphic granular, and granoblastic. Disseminated and banded structures are common. Deposit is divided into quartz-magnetite, quartz-amphibole-magnetite, amphibole-magnetite, and amphibole-rich magnetite types. The second and third types are most important. The deposit is large with resources of 167 million tonnes grading 34.82% Fe, 42.78% SiO2, 0.2467% S, 0.0102% P, and 0.0058% As.


Origin and Tectonic Controls for

Yinshan Metallogenic Belt



Deposits are hosted in a marine overlap volcaniclastic assemblage that is interpreted as forming in in an aulacogen.

REFERENCES: Li Rangdao, 1993.

Qinglong Metallogenic Belt of

Banded Iron Formation (BIF, Algoma Fe) and

Clastic-Sediment-Hosted Sb-Au Deposits

(Belt QL) (North China)

This Paleoproterozoic metallogenic belt is hosted in marine volcaniclastic and sedimentary basins of West Liaoning-Hebei-Shanxi terrane in the Sino-Korean Craton in the Jidong area (Eastern Hebei Province). The major Fe deposit is at Zhalanzhangzi, and the major Au deposits is at Qinglonghe. This metallogenic belt is 80 km long and ranges up to 30 km wide. BIF deposits are related to the Paleoproterozoic Zhuzhangzi Group and clastic-sediment-hosted Sb-Au deposits are related to the Paleoproterozoic Zhangjiagou Formation in the Qinglonghe Group.


Zhalanzhangzhi Iron (BIF, Algoma Fe) Deposit



This deposit (Zhang Yixia and others, 1986) consists of bedded and stratiform deposits. The main deposit bed is more than 2000 m long and 10 to 30 m thick and is hosted in tourmaline microgneiss, garnet-mica schist in an asymmetric fold. The deposit occurs in the core and at limbs of the fold. The deposits dip between 60 to 70 degree. Deposits are mainly banded, and consist of magnetite, quartz, actinolite, tremolite, and cummingtonite, with minor calcite, garnet, biotite, and pyrite. Grain size is about 0.05 mm. The total Fegrade of of the ores is low and some ores contain high sulphur. The host rocks (Zhuzhangzhi Group) is interpreted as forming in an aulacogen filled mainly with clastic sedimentary rock, carbonates, and intercalated lesser mafic and more abundant of felsic volcanic rock. Host rocks are metamorphosed to amphibolite facies. The deposit is large with reserves of 200 million tonnes Fe.

Qinglonghe Clastic-Sediment-hosted Au-Sb Deposit

This deposit (Wu, Ruzhuo and Hu, Lunji, 1992) occurs in the metamorphosed clastic rocks of the Paleoproterozoic Zhangjiagou Formation. The deposits are veined, stratiform, lenticular. Deposit controls are distribution of the strata and faults. Most deposits show concordant relation to their hosts, and only a few veins cut bedding of host rocks. The two main deposits types are disseminated-veinlet and Au-bearing quartz vein. Main ore minerals are pyrite, arsenopyrite, and gold, and subordinate minerals are pyrrhotite and chalcopyrite. Gangue minerals are plagioclase, quartz, muscovite, biotite, chlorite, calcite, and barite. Deposit minerals display idiomorphic-hypidiomorphic granular textures, and massive and disseminated structures. Sequence of formation of ore minerals is: arsenopyrite, Au-pyrite, and Au-pyrrhotite with chalcopyrite and fine grained pyrite. Five deposits stages are recognized: Au-bearing silica alteration; milky white quartz vein; pyrite; carbonate; and muscovite-potassic feldspar-quartz vein. The Proterozoic strata are interpreted as providing initial Au and with remobilization and concentration in later geological events. The deposit is medium size.


Origin and Tectonic Controls for

Qinglong Metallogenic Belt

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