Characteristics and Tectonic Significance of the Gravity Field in South China

Based on gravity data processed with the matched filter, depth continuation and horizontal gradient we obtained the spatial distribution of the gravity field and made analyses of the tectonic framework of South China. Then, inversion was conducted for the depth to study the depth variation of the boundary between the crust and upper mantle, namely the Mohorovicic discontinuity (Moho). The results demonstrate that the Moho depth in South China ranges from 30 to 40 km, and the crust thins from west to east, 27-29 km under the continent margin and shallow sea. We think it possible that the Tanlu fault crosses the Yangtze River and extends southwards along the Ganjiang and Wuchuan-Sihui faults to the South China Sea, and that there is an E-W hidden structural belt along 24.5°-26°.     

Basement of the South China Sea Area: Tracing the Tethyan Realm

The basement of the South China Sea (SCS) and adjacent areas can be divided into six divisions (regions) – Paleozoic Erathem graben-faulted basement division in Beibu Gulf, Paleozoic Erathem strike-slip pull-apart in Yinggehai waters, Paleozoic Erathem faulted-depression in eastern Hainan, Paleozoic Erathem rifted in northern Xisha (Paracel), Paleozoic Erathem strike-slip extending in southern Xisha, and Paleozoic-Mesozoic Erathem extending in Nansha Islands (Spratly) waters. The Pre-Cenozoic basement in the SCS and Yunkai continental area are coeval within the Tethyan tectonic domain in the Pre-Cenozoic Period. They are formed on the background of the Paleo-Tethyan tectonic domain, and are important components of the Eastern Tethyan multi-island-ocean system. Three branches of the Eastern Paleo-Tethys tectonic domain, North Yunkai, North Hainan, and South Hainan sea basins, have evolved into the North Yunkai, North Hainan, and South Hainan suture zones, respectively. This shows a distinctive feature of localization for the Pre-Cenozoic basement. The Qiongnan (i.e. South Hainan) Suture Zone on the northern margin of the South China Sea can be considered the vestige of the principal ocean basin of Paleo-Tethys, and connected with the suture zone of the Longmucuo-Shuanghu belt–Bitu belt –Changning-Menglian-Bentong-Raub belt, the south extension of Bitu-Changning-Menglian–Ching Mai belt–Chanthaburi-Raub-Bentong belt on the west of South China Sea, and with the Lianhua-Taidong suture zone (a fault along the east side of Longitudinal Valley in Taiwan)–Hida LP/HT (low pressure-high temperature) metamorphic belt–Hida-marginal HP/LT metamorphic belt in southwestern Honshu of Japan, on the east of the South China Sea. The Qiongbei (North Hainan) suture zone may eastwards extended along the Wangwu-Wenjiao fault zone, and connects with the Lufeng-Dapu-Zhenghe-Shangyu (Lianhuashan) deep fault zone through the Pearl River Mouth Basin. The Meso-Tethys developed on the south of the South China Sea. The Nansha Trough may be considered the vestige of the northern shelf of the Meso-Tethys. The oceanic crust of the Meso-Tethys has southwards subducted along the subduction-collision-thrust southern margin of the Nansha Trough with a subduction-pole opposite to those of the Yarlung Zangbo-Mytkyina-Bago zone on the west of the South China Sea, and the Meso-Tethyan (e.g. Northern Chichibu Ocean of the Meso-Tethys) suture zone “Butsozo tectonic line” in the outer belt of the Jurassic-Early Cretaceous terrene group in southwest Japan, on the east of the South China Sea.     

SOME CORRELATIONS BETWEEN THE GEOLOGY OF CHINA PROPER AND THE GEOLOGY OF MONGOLIA

During the summer of 1930 we had. thanks to the Central Asiatic Expedition led by Dr. R.C. Andrews, a splendid opportunity for studying the geological formations of SE. Gobi, along the Kalgan-Urga trail, South and     

Deformation Structures of the Madao Gneiss in South Qinling: Structural Analysis, Geochronological Constraints, and Tectonic Implications

The tectonic evolution of South Qinling,which is a main part of the Qinling orogenic belt,is still in dispute and deformation history of South Qinling is poorly studied.In this paper,detailed structural,microstructural,quartz c-axis fabric analysis,and geochronology results for the Madao gneiss in South Qinling are presented to characterize the deformation history.Results show that rocks in the northern part(Tiefodian-Laozhanggou) experience general shearing and deform at relative low temperature.The shear sense generally is south to north.In contrast,rocks in the southern part(Laozhanggou-Panjiahe) are weakly sheared with pure shear features and evidence of hightemperature deformation.Based on the analyses,we conclude that there exist two distinct deformation geometries in the Madao gneiss and accordingly we can divide the deformation into two stages.The early stage is represented by regional shortening,while the late stage features northward thrust shearing and evidence shows that it was a progressive process between them.LA-ICP MS U-Pb dating of zircons from pre-deformational migmatite veins yields age of 198.5 ± 2.0 Ma.This result,in combination with the age of post-deformational granite,indicates that the northward thrust shearing of the Madao gneiss occurred in the Late Triassic.In view of these results and other reported data in South Qinling,we propose that deformation in Madao gneiss may result from the initial collision and subsequent northward accretion in Late Triassic.     

Crustal Structure across the Northwestern Margin of South China Sea: Evidence for Magma‐poor Rifting from a Wide‐angle Seismic Profile

We present results from a 484 km wide-angle seismic profile acquired in the northwest part of the South China Sea (SCS) during OBS2006 cruise. The line that runs along a previously acquired multi-channel seismic line (SO49-18) crosses the continental slope of the northern margin, the Northwest Subbasin (NWSB) of the South China Sea, the Zhongsha Massif and partly the oceanic basin of the South China Sea. Seismic sections recorded on 13 ocean-bottom seismometers were used to identify refracted phases from the crustal layer and also reflected phases from the crust-mantle boundary (Moho). Inversion of the traveltimes using a simple start model reveals crustal images in the study area. The velocity model shows that crustal thickness below the continental slope is between 14 and 23 km. The continental part of the line is characterized by gentle landward mantle uplift and an abrupt oceanward one. The velocities in the lower crust do not exceed 6.9 km/s. With the new data we can exclude a high-velocity lower crustal body (velocities above 7.0 km/s) at the location of the line. We conclude that this part of the South China Sea margin developed by a magma-poor rifting. Both, the NWSB and the Southwest Sub-basin (SWSB) reveal velocities typical for oceanic crust with crustal thickness between 5 and 7 km. The Zhongsha Massif in between is extremely stretched with only 6–10 km continental crust left. Crustal velocity is below 6.5 km/s; possibly indicating the absence of the lower crust. Multi-channel seismic profile shows that the Yitongansha Uplift in the slope area and the Zhongsha Massif are only mildly deformed. We considered them as rigid continent blocks which acted as rift shoulders of the main rift subsequently resulting in the formation of the Northwest Sub-basin. The extension was mainly accommodated by a ductile lower crustal flows, which might have been extremely attenuated and flow into the oceanic basin during the spreading stage. We compared the crustal structures along the northern margin and found an east-west thicken trend of the crust below the continent slope. This might be contributed by the east-west sea-floor spreading along the continental margin.     

Late Cambrian to Early Silurian Granitic Rocks of the Gemuri Area, Central Qiangtang, North Tibet: New Constraints on the Tectonic Evolution of the Northern Margin of Gondwana

The Paleozoic tectonic framework and paleo–plate configuration of the northern margin of Gondwana remain controversial. The South Qiangtang terrane is located along the northern margin of Gondwana and records key processes in the formation and evolution of this supercontinent. Here, we present new field, petrological, zircon U-Pb geochronological, and Lu-Hf isotopic data for granitic rocks of the Gemuri pluton, all of which provide new insights into the evolution of the northern margin of Gondwana. Zircon U-Pb dating of the Gemuri pluton yielded three concordant ages of 488.5 ± 2.1, 479.9 ± 8.9, and 438.5 ± 3.5 Ma. Combining these ages with the results of previous research indicates that the South Qiangtang terrane records two magmatic episodes at 502–471 and 453–439 Ma. These two episodes are associated with enriched zircon Hf isotopic compositions(εHf(t) =-10.1 to-3.9 and-16.6 to-6.5, respectively), suggesting the granites were formed by the partial melting of Paleoproterozoic–Mesoproterozoic metasedimentary rocks(Two–stage Hf model ages(TCDM) = 2094–1704 and 2466–1827 Ma, respectively). Combining these data with the presence of linearly distributed, contemporaneous Paleozoic igneous rocks along the northern margin of Gondwana, we suggest that all of these rocks were formed in an active continental margin setting. This manifests that the two magmatic episodes within the Gemuri area were associated with southward subduction in the Proto-(Paleo-) Tethys Ocean.     

Tectonic and Hydrocarbon Accumulation Elements Characteristics of the Tethyan Realm in South China

Abstract: The evolution of the global Tethys Sea can be classified into three stages, Proto-Tethys, Paleo-Tethys and Neo-Tethys. The Tethyan realm has distinctive features of zonations and segmentations along north-south and east-west, respectively, and has variable richness in oil and gas. The petroleum geological conditions of Tethys are complicated, partly represented by multi-layer of source and seal rocks, and reservoirs. The hydrocarbon accumulation elements and periods of the Tethyan realm show gradually younger from west to east and north to south. South China is located in the north belt and Yangtze segment of the Tethyan realm, and its polycyclic tectonic movements were governed by the Tethyan and Pacific realms. The blocks in South China rotated clockwise and counter-clockwise during their drift northward from Gondwana. The belts and segmentations of Tethys in South China are also clear, with six tectonic belts including: Chuxiong-Sichuan; middle Guizhou-Hunan-Hubei; lower Yangtze; Xuefeng-Jiangnan; Guangxi-Hunan-Jiangxi; and Cathaysia. Numerous faults, including compressional, compressional-shear, extensional, extensional-shear and shear are well developed in South China. The fault strikes are mainly NE, NW and NS, in which the NE is the dominant direction. Lower, middle and upper hydrocarbon assemblages, respectively corresponding to Proto-, Paleo- and Neo-Tethys, formed in the Tethyan realm of South China with the lower and middle having excellent hydrocarbon accumulation conditions. An integrated analysis of tectonic evolution, superimposed deformation and later hydrocarbon preservation shows that during the Neo-Tethyan stage in South China, continental sediments were deposited and experienced intense tectonic deformation, which had resulted in different hydrocarbon pool-forming features from those of the Neo-Tethyan realm.     

Paleoseismological Study of the Late Quaternary Slip-rate along the South Barkol Basin Fault and Its Tectonic Implications, Eastern Tian Shan, Xinjiang

The easternmost Tian Shan lies in eastern Xinjiang, Central Asia. The South Barkol basin fault(SBF) in the northern part of the easternmost Tian Shan is a major tectonic structure in this orogenic region. The late Quaternary activity, paleoseismology, and deformation characteristics of the fault provide important clues for understanding the tectonic process of the eastern Tian Shan orogen and implementing seismic mitigation. Through interpretation of high-resolution satellite images, unmanned aerial vehicle measurements, and detailed geological and geomorphic investigations, we suggest that the fault exhibits clear left-lateral slip along its western segment. Paleoseismic trenches dug near Xiongkuer reveal evidence of six large paleoearthquakes. The four latest paleoearthquakes were dated: the oldest event occurred at 4663 BC–3839 BC. Data on the horizontal offsets along the probable 1842 Barkol earthquake coseismic rupture suggest clear multiple relationships between cumulative offsets and possible ~4 m of coseismic left-lateral slip per event. From the cumulative offsets and 14 C sample ages, we suggest an average Holocene left-lateral slip rate of 2.4–2.8 mm/a on the SBF, accounting for ~80% of lateral deformation within the entire eastern Tian Shan fault system. This result is comparable with the shortening rate of 2–4 mm/a in the whole eastern Tian Shan, indicating an equal role of strike-slip tectonics and compressional tectonics in this orogen, and that the SBF may accommodate substantial lateral tectonic deformation.     

中国南极冰川学研究10 a回顾与展望

The study of Antarctic glaciology in China is reviewed with the emphasis on the past decade. Much progress has been achieved in the physical characteristics of the Antarctic ice sheet and caps and in the study of climatic and environmental records in Antarctic snow and ice. Through observations of snow profiles of numerous snow-pits and shallow cores in the Wilkes Land and Lambert Glacier basin and along the route of the 1990 International Trans-Antarctica Science Expedition (ITASE), the regional features of snow deposition and densification in Antarctica were revealed. The Nelson Island ice cap in South Shetland Islands was investigated in detail that　greatly enriched the knowledge of glaciers under a sub-Antarctic maritime climate. From the analyses of shallow ice cores and surface snow samples, in particular those taken along the ITASE route, the systematic data of stable isotopes, soluble impurities and heavy metal Pb in present precipitation in Antarctica has been obtained. Some suggestions are proposed through discussing the present hot points in the above fields.     

http://www.sciencedirect.com/science/article/pii/S1674987113000364

The South Tianshan Orogen and adjacent regions of Central Asia are located in the southwestern part of the Central Asian Orogenic Belt.The formation of South Tianshan Orogen was a diachronous,scissors-like process,which took place during the Palaeozoic,and its western segment was accepted as a site of the fnal collision between the Tarim Craton and the North Asian continent,which occurred in the late Palaeozoic.However,the post-collisional tectonic evolution of the South Tianshan Orogen and adjacent regions remains debatable.Based on previous studies and recent geochronogical data,we suggest that the fnal collision between the Tarim Craton and the North Asian continent occurred during the late Carboniferous.Therefore,the Permian was a period of intracontinental environment in the southern Tianshan and adjacent regions.We propose that an earlier,small-scale intraplate orogenic stage occurred in late Permian to Triassic time,which was the frst intraplate process in the South Tianshan Orogen and adjacent regions.The later largescale and well-known Neogene to Quaternary intraplate orogeny was induced by the collision between the India subcontinent and the Eurasian plate.The paper presents a new evolutionary model for the South Tianshan Orogen and adjacent regions,which includes seven stages:(I)late Ordovicianeearly Silurian opening of the South Tianshan Ocean;(II)middle Silurianemiddle Devonian subduction of the South Tianshan Ocean beneath an active margin of the North Asian continent;(III)late Devonianelate Carboniferous closure of the South Tianshan Ocean and collision between the Kazakhstan-Yili and Tarim continental blocks;(IV)early Permian post-collisional magmatism and rifting;(V)late PermianeTriassic the frst intraplate orogeny;(VI)JurassicePalaeogene tectonic stagnation and(VII)NeoceneeQuaternary intraplate orogeny.     

An Overview on the Composition and Age of Upper Crust of Proto-Tethyan Lajishan Intra-oceanic Arc, NE Tibet Plateau

Identification and anatomy of oceanic arcs within ancient orogenic belt are significant for better understanding the tectonic framework and closure process of paleo-ocean basin. This article summarizes the geological, geochemical, and geochronological characteristics of upper crust of Proto-Tethyan Lajishan intra-oceanic arc and provides new data to constrain the subduction evolution of the South Qilian Ocean. The intra-oceanic arc volcanic rocks, including intermediate–mafic lava, breccia, tuff, and minor felsic rocks, are distributed along southern part of the Lajishan ophiolite belt. Geochemical and isotopic compositions indicate that the intermediate–mafic lava were originated from depleted mantle contaminated by sediment melts or hydrous fluids, whereas the felsic rocks were likely generated by partial melting of juvenile mafic crust in intra-oceanic arc setting. Zircons from felsic rocks yield consistent and concordant ages ranging from 506 to 523 Ma, suggesting these volcanic rocks represent the relicts of upper crust of the Cambrian intra-oceanic arc. Combined with the Cambrian forearc ophiolite and accretionary complex, we suggest that the Cambrian intra-oceanic arc in the Lajishan ophiolite belt is belonging to the intra-oceanic arc system which was generated by south-directed subduction in the South Qilian Ocean at a relatively short interval between approximately 530 and 480 Ma.     

Tectonic evolution of the West Kunlun Orogenic Belt along the northern margin of the Tibetan Plateau:Implications for the assembly of the Tarim terrane to Gondwana

The West Kunlun orogenic belt(WKOB) along the northern margin of the Tibetan Plateau is important for understanding the evolution of the Proto-and Paleo-Tethys oceans. Previous investigations have focused on the igneous rocks and ophiolites distributed mostly along the Xinjiang-Tibet road and the China-Pakistan road, and have constructed a preliminary tectonic model for this orogenic belt. However, few studies have focused on the so-called Precambrian basement in this area. As a result, the tectonic affinity of the individual terranes of the WKOB and their detailed evolution process are uncertain. Here we report new field observations, zircon and monazite U-Pb ages of the "Precambrian basement" of the South Kunlun terrane(SKT) and the Tianshuihai terrane(TSHT), two major terranes in the WKOB. Based on new zircon U-Pb age data, the amphibolite-facies metamorphosed volcanosedimentary sequence within SKT was deposited during the late Neoproterozoic to Cambrian(600-500 Ma), and the flysch-affinity Tianshuihai Group, as the basement of the TSHT, was deposited during the late Neoproterozoic rather than Mesoproterozoic. The rock association of the volcano-sedimentary sequence within SKT suggests a large early Paleozoic accretionary wedge formed by the long-term lowangle southward subduction of the Proto-Tethys Ocean between Tarim and TSHT. The amphibolitefacies metamorphism in SKT occurred at ca. 440 Ma. This ca. 440 Ma metamorphism is genetically related to the closure of the Proto-Tethys Ocean between Tarim and the Tianshuihai terrane, which led to the assembly of Tarim to Eastern Gondwana and the final formation of the Gondwana. Since the late Paleozoic to early Mesozoic, the northward subduction of the Paleo-Tethys Ocean along the HongshihuQiaoertianshan belt produced the voluminous early Mesozoic arc-signature granites along the southern part of NKT-TSHT. The Paleo-Tethys ocean between TSHT and Karakorum closed at ca. 200 Ma, as demonstrated by the monazite age of the paragneiss in the Kangxiwa Group. Our study does not favor the existence of a Precambrian basement in SKT.     

New Zircon U‐Pb Age of Late Devonian Tuff in Guangxi,South China and the Significance for the Paleo‐Tethys Branch Ocean

正Objective The eastern extending range of the Paleo-Tethys Ocean in southwest China has always been focused and controversial.At the beginning of this century some scholars proposed that the Paleo-Tethys Branch Ocean may extend to the Babu–Pingxiang and Cengxi areas along the stouthwestern margin of the South China Block(Cai and Zhang,2009).However,the pivotal proof of Late     

An Early Paleozoic Tectonic Mélange at the Western Margin of West Cathaysia: Constraints from Organic-walled Microfossils

The Jiangshan-Shaoxing-Pingxiang Fault(JSP Fault) is traditionally considered as the boundary between the Yangtze and Cathaysia blocks in South China. Whether the previously defined Shenshan and Kuli formations located along the JSP fault and near the Xinyu City, Jiangxi Province, are continuous strata or parts of a tectonic mélange is important for understanding the geological history of South China. A carbonaceous phyllite from the area, previously considered as part of the Neoproterozoic Shenshan and Kuli formations, is analyzed palynologically in this study. The AsteridiumComasphaeridium acritarch assemblage found in the slate can be correlated with the basal Cambrian AsteridiumHeliosphaeridium-Comasphaeridium(AHC) acritarch assemblage in Tarim and the Yangtze Block. The early Cambrian biostratigraphical age assignment for the carbonaceous phyllite indicates the presence of both Neoproterozoic and Cambrian rocks in the sedimentary package, and supports that the package is a part of tectonic mélange rather than a continuous Neoproterozoic strata. The Cambrian slate is the youngest known lithology in the mélange at present.     

Early Cretaceous Tectonics and Evolution of the Tibetan Plateau

Selected geological data on Early Cretaceous strata, structures, magmatic plutons and volcanic rocks from the Kunlun to Himalaya Mountains reveal a new view of the Early Cretaceous paleo-tectonics and the related geodynamic movement of the Tibetan Plateau. Two major paleo-oceans, the Mid-Tethys Ocean between the Qiangtang and Lhasa blocks, and the Neo-Tethys Ocean between the Lhasa and Himalayan blocks, existed in the Tibetan region in the Early Cretaceous. The Himalayan Marginal and South Lhasa Seas formed in the southern and northern margins of the Neo-Tethys Ocean, the Central Tibet Sea and the Qiangtang Marginal Sea formed in the southern and northern margins of the Mid-Tethys Ocean, respectively. An arm of the sea extended into the southwestern Tarim basin in the Early Cretaceous. Early Cretaceous intensive thrusting, magmatic emplacement and volcanic eruptions occurred in the central and northern Lhasa Block, while strike-slip formed along the Hoh-Xil and South Kunlun Faults in the northern Tibetan region. Early Cretaceous tectonics together with magmatic K2O geochemistry indicate an Early Cretaceous southward subduction of the Mid-Tethys Oceanic Plate along the Bangoin-Nujiang Suture which was thrust ~87 km southward during the Late Cretaceous-Early Cenozoic. No intensive thrust and magmatic emplacement occurred in the Early Cretaceous in the Himalayan and southern Lhasa Blocks, indicating that the spreading Neo-Tethys Oceanic Plate had not been subducted in the Early Cretaceous. To the north, terrestrial basins of red-beds formed in the Hoh-Xil, Kunlun, Qilian and the northeastern Tarim blocks in Early Cretaceous, and the Qiangtang Marginal Sea disappeared after the Qiangtang Block uplifted in the late Early Cretaceous.     

The Jiangnan orogenic belt between the Yangtze and Cathaysia blocks for Neoproterozoic context

In recent years, more high quality zircon U-Pb ages have been obtained from Neoproterozoic strata in the South China continental block. A refined chronostratigraphic framework is being set up on these data. A basis of the high quality chronostratigraphic system is fundamental for global Precambrian study and strata correlation. Our recent geological studies focus on systematic SHRIMP zircon dating. We will refine the chronostratigraphic framework of the Neoproterozoic and the start time of the cover beds of the Shuangqiaoshan Group basing on the new SHRIMP zircon ages from the volcanic ash beds in the Hengyong and Anlelin formations. Accordingly, we will also discuss Neoproterozoic tectonostratigraphy in South China     

Deformation at the Easternmost Altyn Tagh Fault: Constraints on the Growth of the Northern Qinghai–Tibetan Plateau

How the Altyn Tagh fault(ATF) extends eastwards is one of the key questions in the study of the growth of the Qinghai–Tibetan Plateau. Detailed fieldwork at the easternmost part of the ATF shows that the ATF extends eastward and bypasses the Kuantan Mountain; it does not stop at the Kuantan Mountain, but connects with the northern Heishan fault in the east. The ATF does not enter the Alxa Block but extends eastward along the southern Alxa Block to the Jintanan Mountain. The Heishan fault is not a thrust fault but a sinistral strike-slip fault with a component of thrusting and is a part of the ATF. Further to the east, the Heishan fault may connect with the Jintananshan fault. A typical strike-slip duplex develops in the easternmost part of the ATF. The cut and deformed Quaternary sediments and displaced present gullies along the easternmost ATF indicate that it is an active fault. The local highest Mountain(i.e., the Kuantan Mountain) in the region forms in a restraining bend of the ATF due to the thrusting and uplifting. The northward growth of the Qinghai–Tibetan Plateau and the active deformation in South Mongolia are realized by sinistral strike-slipping on a series of NE–SW-trending faults and thrusting in restraining bends along the strike-slip faults with the northeastward motion of blocks between these faults.     

The distribution of dimethylcarbazoles in oils from the Pearl River Mouth Basin, South China Sea

C2-carbazole isomers have been investigated in crude oils from the Hui-Liu Structure Ridge (HLSR) in the Pearl River Mouth Basin (PRMB), South China Sea. The NH shielded isomer, as well as the NH partially shielded isomers, was detected in high abundance and the NH exposed isomers in lower abundance. A small-enrichment trend of 1,8-dimethylcarbazole (DMC) was observed in crude oils along the western part of HLSR (WPHLSR), which may indicate little effect of migration on the C2-carbazole distributions. Two strikingly different distribution patterns of NH partially shielded isomers were observed in the reservoirs along the WPHLSR: one with a preference of 1,3- and 1,6-DMCs and the other with a preference of 1,4- and 1,5-DMCs. All of the oils occurring in the Upper reservoirs have a preference of 1,3- and 1,6-DMCs, whereas those trapped in the Lower reservoirs show a preference of 1,4- and 1,5-DMCs, which may indicate there are two petroleum migration systems in the WPHLSR.     

http://www.sciencedirect.com/science/article/pii/S1674987114001133

A chronological study of seamount rocks in the South China Sea basin provides a great opportunity to understand the expansion and evolution history of the sea basin. In this paper, we analyzed the 40Ar...     

Geological Characteristics and Its Metallogenesis of Daolundaba Copper Polymetallic Deposits,Inner Mongolia

1 Geology Daolundaba copper polymetallic deposit occurs in West Ujimqin Banner,the Xilin Gol League of Inner Mongolia,along the west side of South part of Daxinganling ore belt,whose tectonic position just lies at the junction of Siberian Block in the south part,North China Block in the north and Songliao block in the east.The Daolundaba copper polymetallic deposit is hosted by the Lower Proterozoic Baoyintu group of biotite-plagioclase gneiss(Pt1by),upper Permian Linxi formation of sandy slate(P2l),and the Hercynian Qianjinchang pluton of biotite granite.