Geochronology and Geochemistry of Ore-related Granitoids in the Giant Gariatong Rb Deposit,Tibet and Implications for Rb Metallogeny in China

Rubidium(Rb)deposits mostly occur in the South China and Central Asia orogenic belts and are often closely associated with highly differentiated granites.This study investigates a newly-discovered giant Rb deposit at Gariatong in the Central Lhasa terrane in Tibet.Detailed field studies and logging data revealed that the Rb mineralization mainly occurs in monzogranite and is related to greisenization.LA-ICP-MS U-Pb dating of zircon yielded ages of 19.1±0.2 Ma and 19.0±0.2 Ma for greisenized monzogranite and fresh monzogranite,respectively.The monzogranites are characterized as strongly peraluminous,with high contents of SiO2,Al2O3,K2O and Na2O as well as a high differentiation index.They are enriched in light rare earth and large ion lithophile elements with significant negative Eu anomalies and depleted high fieldstrength elements.Petrological and geochemical features of these ore-related monzogranites suggest that they are highly fractionated S-type granites,derived from remelting of crustal materials in a post-collisional setting.The geochemistry of zircon and apatite points to a low oxygen fugacity of the ore-related monzogranite during the magma’s evolution.The discovery of the Gariatong Rb deposit suggests that the Central Lhasa terrane may be an important region for rare metal mineralization.

PORPHYRY AND SKARN Cu-Mo-Pb-Zn-Ag-Au METALLOGENY OF THE GANGDISE PLUTONIC -VOLCANIC ARC, TIBET

The Gangdise plutonic\|volcanic arc is situated in the eastern section of the Tethys\|Himalaya metallogenic province. It is acknowledged as a “tectonic\|magmatic complex" because of its well\|developed fault and igneous activities. Intermediate to acid plutons and dikes were mainly emplaced in the Upper Cretaceous to Lower Eocene volcanic rocks. The unique tectonic position and extremely complicated evolution history of the Gangdise arc have given rise to favorable conditions for polymetal mineralization. From Xietongmen in the west to Mozhugongka in the east of the arc, Au, Cu, Pb, Zn, and Ag show large ore\|forming potentials with well overlapped and highly intensified polymetal anomalies. In the arc region, many localities, like Jiama (Cu, Pb, Zn, Au, Ag) and Qulong (Cu, Pb, Zn) in Mozhugongka county, Lakang’e (Cu, Pb, Zn, Mo) in Lazi county, Tinggong (Cu, Mo) and Chongjiang (Cu, Mo) in Nimu county, Dabu (Cu, Au) in Qushui county, and Dongga (Au, Cu) in Xietongmen county, have sound prospective for polymetals.

Organic Metallogeny of Weathering Crust RE Deposit

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Geology,Genetic Types and Metallogeny of Gold Deposits in the Eastern Tianshan,Xinjiang

As a typical Palaeozoic island arc system, the eastern Tianshan area, Xinjiang, is different from eastern China but similar to the Meso-Cenozoic island arc metallogenic provinces along the coast of the Pacific Ocean in metallogenic environment, geology and geochemistry. Three types of gold deposits, ductile shear zone-hosted gold deposits (Kanggur ), magmatic hydrothermal gold deposits (Jinwozi) and volcanic- or subvolcanic-hosted gold deposits (Xitan and Mazhuangshan), have been identified in this area. Regionally, gold deposits are structurally controlled by the Kanggur Tag ductile shear zone, Shaquanzi fault, Hongliuhe fault and Yamansu fault. Generally, gold mineralization occurs in the transition zones from volcanic rocks to sedimentary rocks. The horizon bearing well-developed jasper is an important indicator for gold mineralization. Each of the three types of gold deposits has its distinctive metallogenic background and geological-geochemical characteristics.

STRUCTURAL EVOLUTION AND METALLOGENY OF SOUTH XINJIANG METALLOGENIC BELT,JIANGXI,SOUTH CHINA

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Evolution-Motion of Crustobodies and Geotectonic Metallogeny

Following the paper entitled A Preliminary Proposal on Crustobody Geotectonics presented by the first author to the 30th IGC in 1996, this paper further extends and elucidates the concept of crustobody in order to make a unifying study of the evolution and motion of crustal structures and to understand the law governing the formation and development of the earth’ crust. In this paper the characteristics of crustobody evolution-motion are given. The authors lay emphasis on the relationship between crustobody evolution-motion and tectonic metallogeny. In the end, a multiple dynamic system of the crustobody evolution-motion is discussed from internal and external dynamic forces, and the mantle creep in internal dynamic factors is paid special attention to.

Large Igneous Provinces, Their Giant Mafic Dyke Swarms, and Links to Metallogeny

Giant mafic dyke swarms are a key component of the feeder system of Large Igneous Provinces(LIPs),large volume(>0.1 Mkm^3;frequently above>1 M km^3),mainly mafic(-ultramafic)magmatic events of intraplate affinity.

Lineament Analysis of Morphostructures of the Uchur-Maya Basin (Southeastern Siberian Platform) from SRTM Data: Relationship with Metallogeny

Based on digital elevation models SRTM03 and SRTM30_Plus (Shuttle Radar Topography Mission Survey) the technique for detecting major structural elements and elucidating details of the geologic structure including discrimination of linear structures and texture features is elaborated. The computation of the modulus of the first derivative by the co- ordinate, i.

PECULIARITIES OF METALLOGENY OF SOUTH SIBERIA AND WEST MONGOLIA DIWA REGIONS

There are three diwa regions in South Siberia and West Mongolia. One of them is arranged in West Transbaikalia and was formed from Devonian till Carboniferous periods. Numerous deposits of tungsten , tin, molybdenum, REE, synnyrites, urtites are genetically linked with intrusive rocks. The next diwa region is arranged in North Mongolia and South Buryatia. This diwa region was formed in the Late Paleozoic time. The deposits of molybdenum, tungsten, boron, iron, copper, beryllium are genetically linked with magmatic rocks of this region. The third region was formed in Devonian in West Mongollia. The magmatic rocks of this region are represented by alkaline granitoids. Some deposits of REE and rare metals are linked with these rocks.

Crustal architecture and metallogeny associated with the Paleo-Tethys evolution in the Eastern Kunlun Orogenic Belt,Northern Tibetan Plateau

The Eastern Kunlun Orogenic Belt(EKOB)in the Northern Tibet Plateau hosts a wide variety of metal deposits related to the Late Paleozoic to Mesozoic magmatism.In this study,we investigate the spatiotemporal distribution of the Late Paleozoic to Mesozoic granitic rocks and associated metal deposits in the EKOB and provide a comprehensive compilation of the geochronological,geochemical and isotopic data on these rocks.We compute regional zircon Hf isotope and crustal thickness maps from the data,based on which a comprehensive model is proposed involving subduction(ca.270–240 Ma),continental collision(ca.240–224 Ma),and post-collisional extension(ca.224–200 Ma)for the Late Paleozoic to Mesozoic Paleo-Tethys evolution in the EKOB.Zircon Hf isotopic and crustal thickness mapping of Late Paleozoic to Mesozoic magmatic rocks was carried out to evaluate their spatio-temporal and genetic links with the regional metallogeny.The polymetallic Fe-skarn and porphyry Cu(Mo)deposits in the EKOB are located above the Moho uplift region,featuring a comparatively thin crust.Granites associated with porphyry Cu(Mo)and polymetallic Fe skarn mineralization are commonly characterized by highε_(Hf)(t)and younger T_(DM)cvalues,whereas granite related to Cu-Mo-Sn skarn deposits exhibit more variableε_(Hf)(t)values,T_(DM)c ages,and the crust thickness,which suggest that more crustal materials contributed to the formation of Cu-Mo-Sn skarn deposits than those for porphyry Cu(Mo)and polymetallic Fe skarn mineralization.In contrast,vein-type Au deposits are located primarily where the Moho surface displays a depression,i.e.,where the continental crust is relatively thick.The magmatic rocks associated with Au mineralization are characterized by lowε_(Hf)(t)and high T_(DM)cvalues,representing reworked ancient crustal components,similar to those associated with porphyry Mo and epithermal Ag-Pb-Zn-(Au)deposits.Our study indicates that the emplacement of magmatic-hydrothermal deposits was controlled by the crustal structure and magma sources.

Petrographic, Geochemical and Metallogenical Context of the Geological Formations of the Goumere Region (North-East of Cote D’Ivoire): Implication to the Knowledge of Gold Mineralization

The Gouméré region is located in the North-East of Côte d’Ivoire and is located in the South-West of the Bui furrow. In order to highlight the geology of the area studied, 14 samples were taken for studies using petrographic, geochemical and metallogenic methods. The study of macroscopic and microscopic petrography made it possible to highlight two major lithological units: 1) a volcano-plutonic unit, formed of gabbros, basalt, volcaniclastics and rhyodacite;2) a sedimentary unit (microconglomerate). From a geochemical point of view, the results obtained indicate that the plutonites are gabbro and gabbro diorite while the volcanics have compositions of basaltic andesites, rhyolite and dacites. The sediments have a litharenitic to sublitharenitic character. The metallogenic study made it possible to highlight hydrothermal alterations and metalliferous paragenesis on the formations studied. Hydrothermal alteration is characterized by the presence of carbonation, silicification, sericitization, sulfidation and to a lesser degree chloritization. Metalliferous paragenesis consists of pyrite, chalcopyrite, hematite and magnetite.

The microbial metallogeny of weathering crust REE deposits in South China

VERY little is known about the roles of microorganisms in the metallogeny of weathering crust REE deposits, although there has been much literature on REE behavior in weathering conditions. The present note deals with the microorganisms in 4 weathering profiles of an REE deposit and their roles in migration and accumulation of REE in weathering conditions. 1 Cultivation and identification of microorganisms Under strict sterilization, samples were collected from various parts of 4 weathering profiles of granites in a weathering crust REE deposit in South China. The samples were then cultivated for microorganisms with ordinary agars as culture media and then the cultivated microorganisms were dyed and identifiedunder a microscope. The sampled positions and cultivated numbers of microbial colonies are shown

Mesozoic Metallogeny of Southeast Asia: A Preface

Southeast Asia is geographically located south and southwest of China, east of India, and north of Australia, and plays an important role in "the Belt and Road Initiative" of China. Southeast Asia lies on the intersection of the Eurasian, Indian-Australian and Philippine plates, and is located in the easternmost segment of the Tethyan tectonic domain and much of the region can now be regarded as part of the Eurasian Plate (Metcalfe, 2011;Simons et al., 2007).