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Deep seismic reflection profiling revealing the complex crustal structure of the Tongling ore district

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Science china Earth sciences 2004年第3期47卷 193-200页

作者： L5 Qingtian1, HOU Zengqian1, ZHAO Jinhua1, SHI Danian1, WU Xuanzhi1, CHANG Yinfo1, PEI Rongfu1,HUANG Dongding2.& KUANG Chaoyang2.1. Institute of Mineral Resources, chinese academy of geological sciences, beijing 10003.,{2. 2. The Sixth Geophysical Exploration Brigade, Petroleum Bureau of East{2., Nanjing 2.0009,{2. chinese Acad Geol Sci Inst Mineral Resources Beijing 100037 Peoples R China Petr Bur E china Geophys Explorat Brigade 6 Nanjing 210009 Peoples R China

The deep seismic profiling across the Tongling ore district reveals a complex crustal structure. Strong contrasting dipping layered reflections (4—11 s, TWT),which dominate the lower crust of the northern part of the profile, are interpreted as the underplating of the basalt related to extensional tectonism. In the south of the profile, the Yangtze craton is characterized by strong reflections in the middle crust, showing a distinct two-layer crustal structure. Over the region of the Tongling uplift, there appear the complex arc shape reflections, suggesting folded, faulted and intruded structures, and the transparent zone below them reveals the existence of batholith. The south dipping strong reflections between the upper crust and lower crust (4—7 s, TWT) suggest a detachment between them. The detachment provided space for the magma intrusion, and caused the formation of the batholith. The Yangtze craton has a clear Moho re-flection, while the Tongling uplift has a weak Moho, whereas below the reflective lower crust in the northern part of the profile, there are sub-Moho reflections. The abrupt variation of the Moho characteristics within a short distance indicates the complexity of magmatic activity.

关键词： metallogenic belt, ore district, deep seismic profiling, crustal structure.

Experimental Study on the Mechanism for the Formation of Sn- bearing Granite in Northern Guangxi

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Acta Geologica Sinica(English Edition) 1994年第2期68卷 169-182,228页

作者： Liang Xiangji, Qiao Li, Wang Fusheng and Yang Chonghui Institute of geology, chinese academy of geological sciences, {2. Institute of geology Chinese Academy of Geological Sciences Beijing

Experimental results have proved that the Xuefengian Sn-bearing biotite granites were formed by remelting and recrystallization of the Proterozoic metamorphic rocks of the Sibao Group at 500× 105-2.00× 105 Pa and 750-570℃ and further testified that the F- and B-bear-ing aqueous solution played an important part in decreasing the formation temperature of the rocks. The results tally with the reality of the field geology. The authors have thus brought to light the mechanism for the formation of the Sn-bearing biotite granites and expounded the significance of their formation in the crust dynamics of South china.

关键词： experimental study Sn-bearing biotite granites formation mechanism northern Guangxi

Thrust Propagation in the Aqqikkol Lake Area, the East Kunlun Mountains, Northwestern china

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Acta Geologica Sinica(English Edition) 2003年第4期77卷 468-478页

作者： CUI Junwen, CHEN Wen, LI Pengwu, ZHANG Xiaowei and LI Li Institute of geology, chinese academy of geological sciences,{2. Institute of geology Chinese Academy of Geological Sciences Beijing 100037

The western segment of the East Kunlun Mountains is one of the poorly studied regions in northwestern china. Through a structural analysis of the typical sections, we have the following views: (1) There is a very well developed fault system in the western segment of the East Kunlun Mountains and thrust propagation, normal slip and decoupling are the chief deformation events in this area. (2. Although the thrusting started in the Late Carboniferous and Late Triassic-Early Jurassic, strong activity took place in the Miocene-Quaternary when the Kumkol basin was strongly downwarped. (3) The tectonic pattern of coexistence of N-directed thrust propagation and S-directed normal slip in this area is consistent with the general tectonic pattern of the northern Qinghai-Tibet plateau and also very similar to that of the Himalayan region on the southern margin of the Qinghai-Tibet plateau, but their directions between the thrust propagation are opposite and all the strong thrust propagations occurred from the Miocene-Pliocene to Quaternary, a period featuring strong collision between the Indian plate and the Eurasian plate and abrupt uplift of the Qinghai-Tibet plateau. This oppositely directed thrust propagation and normal slip reveal such kinematic characteristics as symmetric propagations of deep-seated materials towards the north and south beneath the Qinghai-Tibet plateau and gravitational sliding of superficial materials towards the interior of the plateau. Therefore, the establishment of the fault system in the study area may provide an approach to the study of deep processes of the northern Qinghai-Tibet plateau and the construction of a unified geodynamic model for the uplift of the Qinghai-Tibet plateau.

关键词： western segment of the East Kunlun Mountains thrust propagation normal slip plate collision dynamic model

MELT AND FLUID INCLUSIONS IN IGNEOUS ROCKS IN CENTRAL XIZANG (TIBET)

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Science in china,Ser.B 1986年第7期29卷 771-784页

作者：王碧香 Institute of geology chinese academy of {2. sciences beijing

Through a study of the characteristics and composition of melt and fluid inclusions in volcanic rocks and their associated granites in the subduction zone of the Tibetan plate, it has been found that the characteristics of the inclusions in quite a few minerals of various rock types are closely related to the nature of molten magmas, thickness of strata and cooling speed. Therefore, their characteristics may be used to discriminate different lithofacies types. In this paper the evolution and crystallization of magmas are discussed on the basis of the glass composition of the inclusions measured using the electron probe, and the gas composition and its parameters are used in elucidating the physico-chemical conditions of rock and ore formation.

关键词： TIBET MELT AND FLUID INCLUSIONS IN IGNEOUS ROCKS IN CENTRAL XIZANG

Impacts of the Wenchuan Earthquake on the Giant Panda Nature Reserves in china

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Journal of Mountain Science 2010年第2期7卷 197-206页

作者： DENG Xiangzheng JIANG Qunou GE Quansheng YANG LinSheng Institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Center for chinese Agricultural Policy Chinese Academy of Sciences Beijing 100101 China Graduate University of the chineseacademy of {2. Beijing 100049 China

The Wenchuan Earthquake that occurred in May of 2.08 caused damages to large areas of Sichuan,Gansu,and Shaanxi provinces in *** from local governments and related management agencies show that the giant panda nature reserves in the earthquake-hit areas were heavily *** estimates in this paper of the impacts of the earthquake on the giant panda in the earthquake-hit areas were made based on the interpretation of remote sensing images and information collected by field survey.A rapid assessment method was designed to estimate the damages of the earthquake on giant panda *** using visual interpretation methods,we decoded the remote sensing images of the disaster area in the 49 giant panda nature *** results showed that the Wenchuan Earthquake and the succeeding secondary geological disasters caused great damages to the giant panda nature reserves and disturbed the normal life of the giant pandas there (e.g.,landscape fragmentation increased significantly).Undoubtedly,the life of the giant pandas there was ***,although the earthquake caused certain impacts on the giant pandas,it did not really threat their *** so,we still strongly advocate for protection of the giant pandas,and have prioritized a couple of measures to be taken to restore the giant panda nature reserves in the earthquake-hit areas.

关键词： Wenchuan earthquake Remote sensing Giant panda Giant panda nature reserve Rapid assessment method

^(14)C measurement of forest soils in Dinghushan Biosphere Reserve

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chinese Science Bulletin 1999年第3期44卷 251-256页

作者： SHEN Chengde , LIU Dongsheng (LIU Tungsheng) , PENG Shaolin, SUN Yanmin , JIANG Mantao , Yl Weixi , XING Changping , GAO Quanzhou , LI Zhi’an and ZHOU Guoyi Guangzhou Institute of Geochemisry, chinese academy of {2., Guangzhou 510640, china Institute of geology, chinese academy of {2. , beijing 10002., china South china Institute of Botany, chinese academy of {2., Guangzhou 510650, china Guannzhou Institute of Geochemisry Chinese Academy of Sciences Guanazhou China Institute of geology Chinese Academy of Sciences Beijing China South china Institute of Botany Chinese Academy of Sciences Guangzhou China

Organic carbon in forest soils of Qingyunsi and Wukesong profiles can be divided into fast and slow components. Δ14C values of these profiles decrease with increasing of depth. The Δ14C values in 30—40 cm depth interval of Wukesong profile are decreasing sharply until a very low value,showing that a strong geological environment change occurred about 1 560 years ago. The 14C apparent ages of Wukesong profile show that the coniferous and broad-leaf mixed forests around Wukesong profile have been developing since 42. a BP, which is consistent with historical documents. The penetrating depths of "bomb 14C" in Qingyunsi and Wukesong profiles are 10 and 2. cm, respectively.

关键词： Dinghushan forest soil 14C tracing 14C apparent age.

A　Lithospheric　Boundary　between　Eurasia　and　Gondwanaland　in　Eastern　Tethyan　Orogen：　Implication　from　Geochemistry　of　Continental　Basalts　in　Southwestern　china

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Continental Dynamics 1996年第1期 49-55页

作者： Yallg Kaihui(Instilule Of geology, chinese academy of geological sciences, {2., 10003.7, china)

ＡＬｉｔｈｏｓｐｈｅｒｉｃＢｏｕｎｄａｒｙｂｅｔｗｅｅｎＥｕｒａｓｉａａｎｄＧｏｎｄｗａｎａｌａｎｄｉｎＥａｓｔｅｒｎＴｅｔｈｙａｎＯｒｏｇｅｎ：ＩｍｐｌｉｃａｔｉｏｎｆｒｏｍＧｅｏｃｈｅｍｉｓｔｒｙｏｆＣｏｎｔｉｎ... 详细信息

ＡＬｉｔｈｏｓｐｈｅｒｉｃＢｏｕｎｄａｒｙｂｅｔｗｅｅｎＥｕｒａｓｉａａｎｄＧｏｎｄｗａｎａｌａｎｄｉｎＥａｓｔｅｒｎＴｅｔｈｙａｎＯｒｏｇｅｎ：ＩｍｐｌｉｃａｔｉｏｎｆｒｏｍＧｅｏｃｈｅｍｉｓｔｒｙｏｆＣｏｎｔｉｎｅｎｔａｌＢａｓａｌｔｓｉｎＳｏｕ...

关键词： Geochemistry Implication Eastern Gondwanaland

Yixunite and Damiaoite—A Twin of New Native Alloys of Indium and Platinum from the Yanshan Mountains

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Acta Geologica Sinica(English Edition) 1997年第4期71卷 480-485,512-513页

作者： Yu ZuxiangInstitute of geology, chinese academy of geological sciences, 2. Baiwanzhuan,{2. Institute of geology Chinese Academy of Geological Sciences 26 Baiwanzhuan Beijing 100037 [?]Yu Zuxiang Born in 1930 graduated from the Specialty of Mineralogy and Petrology Beijing College of Geology in 1953 now Research Professor of the Institute of geology Chinese Academy of Geological Sciences having long engaged in the study of mineralogy.

Yixunite and damiaoite Were found in a cobalt- and copper-bearing platinum ore vein of a contact metasomatic deposit. The chief ore minerals are bornite, chalcopyrite, magnetite and carrollite. The platinum minerals include moncheite, sperrylite, daomanite, cobalt malanite and cooperite. Yixunite and damiaoite occur as immiscible globules, 1.0 to 2.0 mm in diameter. Yixunite is always in the central part of a globule. It is opaque with metallic lustre, bright white colour and black streak. HM = 5.8; VHN50 = 634 kg/mm2.(573-681 kg/ mm2.; insoluble in HCl, HNO3, HF or H3PO4; no cleavage; no magnetism. Density is hard to measure because of small grain size. Calculated density = 18.2. g/cm3. Reflective colour is bright white with a yellowish tint. Isotropic. The mean analytical results (ranges) (%) are: Pt 82.8 (81.8-83.6), In 16.4(15.6-17.1) and total 99.2. The empirical formula (based on 4 atoms) is Pt2.993 In1.007 . The five strongest lines of X-ray diffraction (hkl, d,I) are 111, 2.30 (100); 2.0, 1.99 (60); 2.2. 1.411 (40);311, 1.2.3 (80); 2.2. 1.151(40). Space group: Pm3m with a =0.3988(3) nm and Z= 1. Damiaoite occurs as single globules or was exsolved from yixunite. Opaque with metallic lustre; bright white colour with black streak; HM = 5.3; VHN50 = 485 kg/mm2.(434-52. kg/mm2.; insoluble in HC1, HNO3, HF or H3PO4; cleavage: no; magnetism: no. Density: hard to measure because of small grain size. Calculated density = 10.95 g/ cm3. Reflective colour is bright white with a yellowish tint. Isotropic. The mean analytical results (ranges) (%) are Pt 45.6 (45.4-46.0), In 53.5 (52.4-53.9), total 99.1. The empirical formula (based on 3 atoms) is Pt0.002.In1.998. The six strongest lines of X-ray diffraction (hkl.d,I) are 2.0,2.2. (100); 311,1.92.(60); 400,1.59 (60); 42.,1.2.9 (80); 440,1.12. (60); 62.,1.006 (70). Space group: Fm3m with a = 0.6364 (3) nm and Z = 4.

关键词： yixunite damiaoite new native alloys cobalt- and copper-bearing platinum ore vein contact metasomatic deposit

Indian Ocean-MORB-type isotopic signature of Yushigou ophiolite in North Qilian Mountains and its implications

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Science china Earth sciences 2006年第6期49卷 561-572页

作者： HOU Qingye1,2. ZHAO Zhidan1,2. ZHANG Hongfei3, ZHANG Benren3 & CHEN Yuelong2.1. State Key Laboratory of geological Processes and Mineral Resources, china University of Geo{2., beijing 100083, china 2. School of Earth Science and Mineral Resources, china University of Geo{2., beijing 100083, china 3. Faculty of Earth {2., china University of Geo{2., Wuhan 430074, china 1. State Key Laboratory of geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China 2. School of Earth Science and Mineral Resources China University of Geosciences Beijing 100083 China 3. Faculty of Earth sciences China University of Geosciences Wuhan 430074 China

In order to explore the disputed issue concerning the tectonic affinity ofthe ancient ocean mantle of North Qilian Mountains (NQM), geochemical and Sr, Nd, Pb isotopiccompositions of pillow basalts of the Yushigou Ophiolite (YSGO) suite from NQM have been analyzedsystematically. The pillow basalts exhibit tholeiitic characteristics, with flatchondrite-normalized REE patterns ((La/Yb)_N = 0.98—1.2.). They display no Nb, Ta, Zr, Hf negativeanomalies, and show MORB features in 2.b-Zr/4-Y and Ti/100-Zr-YX3 tectonic discrimination *** results indicate that the Yushigou ophiolite is most likely to be formed in a mid-ocean ridgeor mature back-arc basin. Their isotopic data show a relatively broad and enriched ^(87)Sr/^(86)Sr(0.70509 — 0.70700), restricted ^(143)Nd/^(144)Nd (0.512.55-0.512.78). Pb isotopes are in the rangeof ^(2.6)Pb/^(2.4)Pb (18.054-2..562., ^(2.7)Pb/^(2.4)Pb (15.537-15.743) and ^(2.8)Pb/^(2.4)Pb(38.068-38.530). These isotopic data imply that the basalts originated from the depleted mantle(DMM), with the involvement of enriched mantle components (mainly EMII). Geochemical comparisonsbetween the basalts in YSGO and the MORB-type basalts of ophiolite suites occurring in the knownancient Tethyan tectonic domain indicate that the ancient oceanic mantle represented by YSGO suiteforming in early Paleozoic in the North Qilian Moutains is very similar to the Tethyan mantle inboth trace elements and isotopic compositions. The North Qilian Mountains should be a part of theTethyan tectonic domain in early Paleozoic. This further implies that the Tethyan tectonic domaincan be deduced to early Paleozoic in the study area, which will be helpful to discussing thetectonic affinity and evolution of the North Qilian Mountains.

关键词： geochemistry, Indian Ocean-MORB-type isotopic signatures, Tethyan tectonic domain, Yushigou ophiolite, North Qilian Mountains.