Chief Editor:HOU Zengqian
Governing Body:China Association for Science and Technology
Organizer:Geological Society of China
start publication :1922
ISSN:ISSN 1000-9515
CN:CN 11-2001/P
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LUO Huilin , HU Shixue , CHEN Liangzhong Yunnan Institute of Geological Sciences , Baita Road , Kunming , Yunnan
2001, 75(4).
Abstract:Two new chordates, Cathaymyrus haikouensis Luo et Hu sp. nov. and Zhongxiniscus intermedius Luo et Hu gen. et sp. nov. are studied in this paper. Both display numerous S-shaped myomeres on their trunk. C. haikouensis shows a long and slim body similar to that of Cathaymyrus diadexus Shu et al., Zhongxiniscus approaches to Myllokunmingia and Haikouichthys in the dorsal fin, but differs in the myomeres. Zhongxiniscus may be the intermediate form between Cathaymyrus and Myllokunmingia and Haikouichthys.
MEI Mingxiang , MA Yongsheng , GUO Qingyin Institute of Earth Sciences , Natural Resources , China University of Geosciences , Beijing China Petrochemical Corporation
2001, 75(4).
Abstract:The Mesoproterozoic Wumishan Formation in the Jixian section of Tianjin is a succession of 3300-m-thick carbonate strata formed in a period of about 100 Ma (1310±20 Ma-1207±10 Ma). In this succession of strata, the carbonate metre-scale cyclic sequences belonging to peritidal type with an approximately symmetrical lithofacies-succession are best developed. The wide development of 1:4 stacking patterns shows that these metre-scale cyclic sequences are genetically related to the short-eccentricity cycles, which are called the Wumishan cyclothems that could truly represent sedimentary cycles. Generally, massive and thick-bedded calcareous dolomites and dolomitic limestones of stromatolite biostromes and thrombolite bioherms constitute the central part of the Wumishan cyclothems. The lower and upper parts consist of tidal flat dolostones, sandy-muddy dolostone and the top part is composed of lagoonal facies dolomitic shales with a paleosol cap. Therefore, an approximately symmetrical lithofacies-successio
WANG Liting , LI Jinling , WANG Xinjin , LI Chun , WU Tianzhuang , LIU Jun Bureau of Geology , Mineral Exploration , Development of Guizhou ProvinceGuiyang Institute of Vertebrate Palaeontology , Palaeoanthropology , Chinese Academy of Sciences , Beijing Guizhou Museum , Guiyang
2001, 75(4).
Abstract:This paper briefly reviews the Triassic marine reptile fossils in Guizhou Province, especially the fossils that have been recently found in the Guanling area. Based on three sections at Guanling and Xingyi, Guizhou Province and Luoping, Yunnan Province, four horizons with vertebrate fossils are recognized in the Middle and Upper Triassic of this area; They are from bottom to top: Member I and Member II of the Guanling Formation, and the Zhuganpo Member and the Wayao Member of the Falang Formation.
GONG Yiming Faculty of Earth Science , China University of Geosciences , Wuhan , LI Baohua Laboratory of Marine Geology , Tongji University , Shanghai and WU Yi Guangxi Institute of Geology , Nanning
2001, 75(4).
Abstract:Four hierarchical cyclothems, superbundlesets, bundlesets, bundles and laminae, have been identified from the Devonian Frasnian-Famennian carbonate strata in Guangxi, South China. Their hierarchical structures, ratio relationships and sequence in conodont zones are continuous and stable and can be traced across different facies zones and sedimentary basins. Our data show that hierarchically organized superbundlesets, bundlesets, bundles and laminae correspond to the long eccentricity, eccentricity, obliquity or precession and sub-Milankovitch cycles respectively. Their periods were 400,000, 100,000, 33,333, 16,667 and 8,000-17,000 a, respectively. The ratios of long eccentricity to eccentricity, eccentricity to obliquity, and eccentricity to precession in the Devonian are 1:4, 1:3 and 1:6 respectively. Using these hierarchical Milankovitch cyclothems, chronostratigraphical division and correlation can be realized at a resolution of 100 ka or 10 ka at the Frasnian-Famennian transition. The time intervals of the Upper rhenana Zone, linguiformis Zone, and the Lower, Middle and Upper triangularis Zone are 0.6, 0.8, 0.3, 0.3 and 0.3 Ma, respectively. Sea-level changes of the Frasnian-Famennian transition were not coherent and synchronous at the resolution of 100 ka or 10 ka in the basin-slope carbonate sequences of Guangxi, South China.
2001, 75(4).
Abstract:The Late Neoproterozoic-Early Palaeozoic suture zones within the Central Orogenic Belt of China can be considered a system-the Kunlun-Qilian-Qinling suture system (KQQ suture system). It is basically divided into the western, central and eastern sectors. The western sector consists of the Kuda-Subashi suture zone, the Mazar-Kangxiwar suture and the central West Kunlun microblock. The central sector covers the following five suture zones: the Altun, North Qilian, Qaidam northern marginal, Qimantag-Wutuo and East Kunlun southern marginal sutures, in addition to some microblocks such as the mid-south Qilian, Qaidam, Ayakkum and Maqen microblocks. The eastern sector is composed of the Shangdan suture zone, Mianlue suture zone and central Qinling-Dabie microblock. The KQQ suture system experienced (1) extending-rifting of the Rodinia super-continent in the early-middle Sinian (-780-600 Ma); (2) the formation and evolution of the KQQ archipelagic ocean during the Late Sinian-Ordovician (-600-440 Ma), and (3)
WAN Yusheng , XU Zhiqin , YANG Jingsui , ZHANG Jianxin Institute of Geology , Chinese Academy of Geological Sciences , Beijing
2001, 75(4).
Abstract:Based on geological, chronological, geochemical and Nd isotopic studies of the high-grade basement of the Qilian terrane, the authors have drawn the following main conclusions: (1) the high-grade basement of the Qilian terrane consists mainly of meta-argillo-arenaceous rocks and granites and its bulk part was formed in the period of 0.8-1.0 Ga (the Jinningian period); (2) most of the meta-argillo-arenaceous rocks and granitic rocks have strong negative Eu and Ba anomalies (Eu/Eu*= 0.47-0.71 and Ba/Ba*=0.16-0.64), with fDM and εNd(1.0 Ga) ranging from 1.87 to 2.26 Ga and from -8.54 to -4.06 respectively, showing relatively high maturity; and (3) the Jinningian granitic rocks are a typical product of continent-continent collision, being probably related to the formation of the supercontinent Rodinia. These studies, combined with the study of high-grade basement rocks near the Qilian terrane, suggest that before the Jinningian period, the Qilian-Qaidam northern-margin terrane and Dunhuang-Alxa terrane wer
DU Yuansheng , GONG Shuyun , HAN Xin , WANG Jiasheng , GU Songzhuand LIN Wenjiao Faculty of Earth Sciences , China University of Geosciences , Wuhan , Hubei
2001, 75(4).
Abstract:The Caledonian erogenic belt of the North Qilian Mountains is an intensely active structure belt. In the process of the Late Caledonian syn-orogeny, the North Qilian-Hexi Corridor area was situated on the tectonic background of a syn-orogenic basin. In response to the orogenic process of the North Qilian Mountains, typical earthquake event deposits-seismites of the Silurian were widely distributed around Hanxia of Yumen City, the Liyuan River of Sunan County and Biandukou of Minle County. In the Hanxia area, where seismites are typically developed, clastic deposits of tidal-flat facies are the background deposits of the Hanxia Formation. The earthquake event deposits are characterized by sandy mudstone veins, synsedimentary microfractures, micro-corrugated laminations and earthquake breccias, which in turn constitute complex seismites, featuring seismic corrugation, shattering and liquefied sandy mudstone veins, auto-clastic breccias and intraclastic parabreccias. The seismites and tidal flat deposits formed typical sequences of earthquake event deposits.
WU Genyao Institute of Geology , Geophysics , Chinese Academy of Sciences , Beijing
2001, 75(4).
Abstract:Recent discoveries of ophiolites indicate that there must be a Palaeotethyan geosuture zone bordering China and Vietnam, which separates the Vietbac block from the South China subcontinent. The Indosinian foreland fold-and-thrust belt bordering Yunnan and Guangxi provided further evidence for the palaeotethysides. The oceanic crust was subducted southwestwards while the magmatic arc migrated northeastwards, and the continent-arc collision occurred in the Late Triassic with the thrusting being extended towards the north or northeast. The features of thrust-nappe structure are discussed, which proved the continental margin of the Palaeotethyan ocean there to be a complicated one. A face-to-face collision occurred first along the NW-striking segment and then along the ENE-striking segment accompanied by transpression or oblique thrusting occurring along the NW-striking one.
CHEN Shuping , ZHANG Yiwei , TANG Liangjie , BAI Guoping Basin , Reservoir Research Centre , University of Petroleum , Changping , Beijing
2001, 75(4).
Abstract:A comprehensive study has been carried out to subdivide and correlate the Upper Carboniferous and Permian sedimentary successions in the Junggar basin based on outcrops and drilling and geophysical data. The study results, combined with geological analyses of the basin's periphery and the basement, as well as studies of the sedimentary rocks within the basin, the unconformities, tectonic geometry, kinematics and geodynamics, lead to the conclusion that the Junggar basin was characterized by the development of foreland basin systems during the Late Carboniferous and Permian. During that period, three foreland basin systems were developed: (1) the northwest foreland basin system, which trended nearly north-south from Mahu to the Chepaizi Palaeo-mountain during its early stage of development and thus it was also referred to as the west foreland basin system; (2) the Karamaili foreland basin system in the east and (3) the Northern Tianshan foreland basin system in the south. These systems are different in size, development stage and time of formation. The first two are developed earlier than the third, but they are smaller in size. All the structures in the Junggar basin have resulted from the integration and superposition of structural elements in the above three systems. In general, the development of the Junggar basin can be divided into four stages. Stage I was marked by the creation and evolution of the marginal western foreland and the peripheral Karamaili foreland basin systems during the Late Carboniferous-early Early Permian (C3-P1ja). Stage II was characterized by the development of complicated foreland basin systems during the middle-late Early Permian (P1jb-Pif) when the three foreland basin systems took their shapes. Stage III was the integration stage of peripheral foreland basin systems during the Middle Permian (P2) in which steady and slow tectonic subsidence prevailed. Stage IV coincided with the shrinking of foreland basin development during the Late Permian (P3).
HU Shouxi , SUN Jinggui , LING Hongfei , YE Ying , Fang Changquan , ZHAO Yiying Department of Earth Sciences , Nanjing University , Nanjing , Jiangsu Department of Earth Sciences , Zhejiang University , Hangzhou , Zhejiang
2001, 75(4).
Abstract:Coesite inclusions are found in kyanite from the Lanshantou eclogite in the Sulu ultrahigh-pressure (UHP) metamorphic belt. This discovery extends the stable region of kyanite to over 2.4 GPa. As an important UHP metamorphic belt in China, the Sulu eclogite belt is the product of A-subduction induced by strong compression of the Yellow Sea terrane to the Jiaodong-northereastern Jiangsu terrane during the interaction of the Eurasian plate and Palaeo-Pacific plate in the Indosinian. It stretches about 350 km and contains over 1000 eclogite bodies. Most eclogites in this belt belong to Groups B and C in the classification of Coleman et al., and commonly contain kyanite, while the Lanshantou eclogite belongs to Group A and contains coesite. The MgO, CaO and FeO contents in garnet and pyroxene show regular variation from the core to the rim, which reveals the PTt paths of progressive metamorphism during the Early Mesozoic (240-200 Ma) and retrogressive metamorphism during the Late Mesozoic and Cenozoic exhumation.
SUN Jinggui , HU Shouxi , LIU Jianmin , SHEN Kun , LING Hongfei Earth Science Institute , Jilin University , Changchun State Key Laboratory of Research on Metallogenesis of Endogenic Ore Deposits , Nanjing University , Nanjing Institute of Geology , Geophysics , Chinese Academy of Sciences , Beijing Shandong Institute , Laboratory of Geological Sciences , Jinan
2001, 75(4).
Abstract:Geologic, petrographic and petrochemical studies of the late Mesozoic K-rich melanocratic dykes, including lamprophyres, andesite porphyrites and dacite-porphyry in the gold field system in the Jiaodong Peninsula, China, have shown that these dykes are characterized by rich potassium and alkali but poor titanium. They belong to an ultra-high potassic, shoshonitic and high potassic calc-alkaline rock series. The parental magma has relatively high initial strontium ratios ((87Sr/86Sr)i=0.70895-0.71140) and low (143Nd/144Nd)i ratios (varying from 0.51135 to 0.51231); and its δ18OSMow. whole rock values vary from +5.8‰ to +10.6‰ with a mean of+7.1‰. These features suggest that the source region of the magma is an enriched mantle wedge transformed from a continental lithosphere mantle which has experienced metasomatism by mantle-derived fluids with H2O-dominated fluids that were provided during the underthrusting of an ocean crust. The initial magma was generated by low-degree partial melting of the enri
ZHENG Jianping , SUN Min , LU Fengxiang , WANG Chunyangand ZHONG Zengqiu Faculty of Earth Sciences , China University of Geosciences , Wuhan , China Department of Earth Sciences , The University of Hong Kong , China
2001, 75(4).
Abstract:This paper presents the primary results of petrologic, mineralogical and petrochemical studies of garnet-bearing granulite facies rock xenoliths from Xinyang, Henan Province. These xenoliths, which are found in a pipe of late Mesozoic volcaniclastic breccia, are of high density (3.13-3.30 g/cm3) and high seismic velocity (Vp = 7.04-7.31 km/s), being products of underplating of basaltic magmas and had experienced granulite facies metamorphism. The underplating and metamorphism took place before the eruption of the host rock. Petrographical studies and equilibrium T-P calculations show that these xenoliths were captured at a 49 km depth and experienced at least a 16 km uplift before they were captured. The dynamics of the uplift could be related to the continent-continent collision between the North China plate and the Yangtze plate during the Triassic.
QIAN Qing , ZHANG Qi Institute of Geology , Geophysics , CAS , P. O. Box , Beijing
2001, 75(4).
Abstract:The Ordovician Laohushan ophiolite, located in the eastern part of the North Qilian Mountains, is mainly composed of meta-peridotites, gabbros and basalts alternating with sediments. The sediments are mainly turbidites, including sandstones, siltstones, cherts etc. Major elements show that the basalts are subalkaline tholeiites and may be analogous to ocean-floor basalts. Except a few N-MORBs, most of the basalts are E-MORBs as indicated by incompatible element ratios such as (La/Ce)N, La/Sm, Ce/Zr, Zr/Y and Zr/Nb. Negative Nb anomaly is common but negative Zr, Hf and Ti anomalies are quite rare. Based on the geochemical characteristics, it is suggested that the Laohushan basalts were formed in a back-arc basin. εNd (t) of the basalts ranges between +3.0 and +8.9 and (87Sr/86Sr), ranges between 0.7030 and 0.7060, indicating a depleted mantle source which was mixed with more or less enriched mantle components. Furthermore, the petrography of the sandstones and geochemistry of the cherts suggest that the
YU Zuxiang Institute of Geology , Chinese Academy of Geological Sciences , Beijing Fei Zhenbi
2001, 75(4).
Abstract:In 1974 the author preliminarily reported two new platinum group minerals-daomanite and hongshiite. The two minerals were accepted by the Commission on New Minerals and Minerals Names of the International Mineralogical Association in 1976 and 1982 respectively. Because of the conditions at that time, the work was preliminary, for example, there were only reflectance values of four wave bands. Recently the author again made measurements of reflectances, corrected cell parameters by the four-circle diffractometer and electron diffraction and supplemented their new occurrences and nomenclature.
2001, 75(4).
Abstract:Branching Macroalgal Fossils of the Early-Middle Cambrian Kaili Formation from Taijiang, Guizhou Province, China YANG Ruidong~(1, 2), MAO Jiaren~2, ZHAO Yuanlong~2, CHEN Xiaoyuan~2 and YANG Xinglian~2 (1. Guizhou Institute of Geochemistry, CAS, Guiyang 550002; 2. Guizhou University of Technology, Guiyang 550003) In this paper, 5 genera and 7 species of the branching macroalgal fossils of the Early-Middle Cambrian Kaili Formation from Taijiang County, Guizhou Province are described, they are: Marpolia spissa Walcott, Marpolia aequalis Walcott, Doushantuophyton lineare Chen, Guizhouella ramulosa Yang
2001, 75(4).
Abstract:NO。1RelationshiP between Mesozoie Magmatism and Subduetion in the Da珑nggan一、恤nshan Area Shao Ji’an(邵济安),Liu Futian(刘福田),Chen Hui(陈辉)and Han Qin自un(韩庆军)Dating of the Karakorum Strike一sliP Fault-·-,一··-·Zhou Yong(周勇),Xu Ronghua(许荣华), Yan Yuehoa(阎月华),pan Yusheng(潘裕生),Tsanyao Rank、、ng(杨灿尧),wei Lo(罗伟)and Wu Chunrmng(吴春明)Roek se五es and oenetie竹pes ofor耐toids in the westem Kunzun On〕geie Belt,e址na-;、,Jiang物ohoi(姜耀辉), 劝ou xunruo(周…
Chief Editor:HOU Zengqian
Governing Body:China Association for Science and Technology
Organizer:Geological Society of China
start publication :1922
ISSN:ISSN 1000-9515
CN:CN 11-2001/P