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
- Most Read
- Most Cited
- Most Downloaded
CHEN Ailin , FENG Hongzhen , ZHU Maoyan , MA Dongsheng , LI Ming Department of Earth Science , Nanjing University , Nanjing , Jiangsu , E-mail: feng.h@jlonline.com Nanjing Institute of Geology , Palaeontology , Chinese Academy of Sciences , Nanjing , Jiangsu Chenjiang Fauna National Geological Park , Chengjiang , Yunnan Wang Si''''en , Xie Guanglian
2003, 77(3).
Abstract:The genus and species Yuyuanozoon magnificissimi gen. et sp. nov., a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China. It has a bipartite body plan and five pairs of chain-formed gill sacs, showing the general characteristics of Ventulicolia. However, the exclusive "atrial cavity" and external gill observed indicate that the new form is different from those previously described as vetulicolians, probably representing a lineage developed within deuterostomes and more primitive than urochordates.
ZHANG Zhifei , HAN Jian , ZHANG Xingliang , LIU Jianni , SHU DeganEarly Life Institute , Key Laboratory for Continental Dynamics of the Ministry of Education , Northwest University , Xi''''an , Shaanxi , E-mail: zhangelle@sina.com.cn Wang Si''''en , Xie Guanglian
2003, 77(3).
Abstract:The Chengjiang Lagerstatte has been celebrated for prolific soft-bodied fossils. Based on specimens recently excavated in the Chengjiang Lagerstatte by the Early Life Institute, Northwest University, Diandongia pista Rong, 1974, is directly revealed to be a pediculate brachiopod, assigned to the Family Botsfordiidae, as is further confirmed by the exceptionally preserved vascular system including dorsal and ventral mantle canals. These specimens described herein exhibit some peculiarities, notably the extremely thin and long pedicles, which suggest that Diandongia is epifaunal rather than burrowing brachiopod. A study of this group of animals indicates that they may be vital to understand the relationship between the lingulids and the remaining brachiopods, and the character evolution of the early Cambrian brachiopods.
XU Xing , CHENG Yennien , WANG Xiaolin , CHANG Chunhsiang Institute of Vertebrate Paleontology , Paleoanthropology , Chinese Academy of Sciences , Beijing , China , E-mail: xu.xing@ivpp.ac.cn Division of Geology , National Museum of Natural Science , Taichung , China Wang Si''''en , Xie Guanglian
2003, 77(3).
Abstract:Pygostyle was previously considered as a unique structure of ornithothoracine birds, used to maneuver tail feathers. A similar structure from an oviraptorosaurian dinosaur was considered functionally associated with the rectrices as in birds. We report a pygostyle-like structure from a therizinosauroid dinosaur. The presence of filamentous integuments, but absence of rectrices, on the tail of this therizinosauroid, combined with other lines of evidence, suggests that the initial function of the pygostyle was not related to the rectrices.
YOU HailuInstitute of Geology , Chinese Academy of Geological Sciences , Baiwanzhuang Road , Beijing , E-mail: hyou@sas.upenn.eduand DONG ZhimingInstitute of Vertebrate Paleontology , Paleoanthropology , Chinese Academy of Sciences , Beijing Wang Si''''en , Xie Guanglian
2003, 77(3).
Abstract:An almost complete skull, which was collected from the Upper Cretaceous of the Bayan Mandahu area in Inner Mongolia, China by the Sino-Canadian Dinosaur Project, is described and assigned to a new genus of protoceratopsid dinosaur, Magnirostris dodsoni gen. et sp. nov. This new taxon is distinguished from other protoceratopsids by the robust rostral bone and the existence of incipient orbital horn cores. The existence of an additional antorbital fenestra indicates a close relationship between Magnirostris and Bagaceratops.
ZHONG Zengqiu , YANG Qijun , SUO Shutian , ZHOU Hanwen , YOU Zhendong China University of Geosciences , Wuhan , Hubei , E-mail: zqzhong@cug.edu.cn Hao Ziguo , Liu Xinzhu
2003, 77(3).
Abstract:Whether the HP and UHP metamorphic rocks of the Dabie-Sulu orogenic belt are of an "in-situ" or "foreign" origin is a long-standing dispute among geologists. Eclogites preserved today in the HP and UHP units constitute merely 5-10%, which are not isolated exotic bodies tectonically intruding into amphibolite facies gneiss, but remnants of once pervasive or widespread eclogite-facies terranes or slabs. The present spatial distribution and forms of the eclogites have resulted from polyphase and progressive deformation and strain partitioning of the HP and UHP slabs. From their formation in deep mantle to their exhumation to the surface, the eclogites have experienced long-term deformation with different strain regimes. The dominant regime responsible for the present spatial distribution and forms of the eclogites is the shear process. The deformation patterns of the eclogites and gneiss matrix also clearly show that the eclogites were metamorphosed in situ. The original distribution area of the eclogites is much larger than that seen today.
WANG Guocan , CHEN Nengsong , ZHU Yunhai , ZHANG Kexin Faculty of Earth Sciences , China University of Geosciences , Wuhan , Hubei , E-mail: wgcan@cug.edu.cn Ren Xifei , Liu Ruixun , Xie Guanglian
2003, 77(3).
Abstract:A high-angle ductile thrusting deformation with top-to-the-north movement penetratively developed in the Proterozoic-Early Paleozoic metamorphic rocks along the Central East Kunlun belt. The deformed rocks suffered epidote-amphibolite facies metamorphism. On the basis of our previous study, we present more data in this paper to further support that the ducdle thrust deformation occurred in the later Caledonian and more detailed information about the deformation. A zircon U-Pb concordant age of 446±2.2 Ma of a deformed granodiorite in the ductile thrust zone was obtained and can be interpreted as the lower limit of the deformation. A syntectonically crystallized and also strongly deformed hornblende Ar/ Ar dating gives an Ar/Ar plateau age of 426.5±3.8 Ma, which represents the deformation age. A strongly orientated muscovite gives an Ar/Ar plateau age of 408±1.6Ma, representing the cooling age after the peak temperature, constraining the upper limit of the ductile thrust deformation. This ductile thru
SU Wen , YOU Zhendong , CONG Bolin , YE KaiLaboratory of Lithosphere Tectonic Evolution , Institute of Geology , Geophysics , Chinese Academy of Sciences , Beijing , E-mail: suwen@mail.igcas.ac.cnChina University of Geosciences , Wuhan , Hubei Xie Guanglian
2003, 77(3).
Abstract:Omphacite grains from UHP eclogite of the Dabie Mountains in eastern China are elongated and show strong lattice preferred orientations (LPOs). Observations by the transmission electron microscopy (TEM) identified not only structures of plastic deformation occurring as free dislocation, dislocation loops and dislocation walls, but also bubbles of water present in the deformed omphacite. The bubbles attach to the dislocation loops which are often connected to one another via a common bubble. Using infrared spectroscopy (IR), two types of hydrous components are identified as hydroxyl and free-water in the omphacite. An analysis of deformation mechanism of microstructure in omphacite suggests that the mineral deformed plastically under UHP metamorphic conditions by dislocation creep through hydrolitic weakening.
SHI Nicheng , BAI Wenji , MA Zhesheng , FANG Qingsong , XIONG Ming , YAN Binggang , DAI Mingquan , YANG JingsuiChina University of Geosciences , Beijing , E-mail: shinicheng@a-l.net.cn Institute of Geology , Chinese Academy of Geological Sciences , Beijing Liu Shuchun , Zhu Xiling
2003, 77(3).
Abstract:Diamond was found in podiform chromitites of ophiolite and harzburgite from Luobusha, Tibet. There are silicate inclusions in some diamond grains from this area. In the present work, the CCD (charge coupled detector) technology of X-ray powder diffraction was applied to the study of the inclusion in diamond from the ophiolite of Tibet. Diffraction patterns are obtained even though the inclusion is only 20 μm in crystal size. The results show that the inclusion in diamond consists of talc and clinochrysotile. Therefore, it is clear that the diamond from the ophiolite of Luobusha, Tibet, is natural diamond rather than a synthetic one.
PAN Mingbao , ZHANG Qinglong , LU Huafu , CHEN Huogen , CHEN Shoujuand ZHU ShipengDepartment of Earth Sciences , Nanjing University , Nanjing , Jiangsu Jiangsu Institute of Geological Survey , Zhujiang Road , Nanjing , Jiangsu , E-mail: andypans@.com Hao Ziguo , Zhu Xiling
2003, 77(3).
Abstract:From Donghai County of Jiangsu Province to Rongcheng County of Shandong Province on the southern border of the Sulu orogen, there exposes an ultramafic belt, accompanied with an ultrahigh-pressure metamorphic zone. It can be further divided into the Xugou belt (the northern belt), and the Maobei-Gangshang belt (the southern belt). One grain of diamond has been discovered from the Zhimafang pyrope peridotite in the southern belt using the heavy mineral method. The diamond grain is 2.13 mm × 1.42 mm × 0.83 mm in size and weighs 9.4 mg. The occurrence of the diamond suggests that the Zhimafang pyrope peridotite xenolith is derived from the lithospheric upper mantle. The tectonic emplacement mechanism of the pyrope peridotite xenoliths in granite-gneisses is obviously different from those in kimberlite. The Sulu orogen was located on the active continental margin of the Sino-Korean craton in the Neoproterozoic. The relatively cold and water-bearing oceanic crustal tholeiite slab subducted beneath the lith
MAO Jianren , HU Qing , XU Naizheng , XIE Fanggui , TAO Kuiyuan , Nanjing Institute of Geology , Mineral Resources , Nanjing , Jiangsu , E-mail: mjrmh@sina.com Hao Ziguo , Zhu Xiling
2003, 77(3).
Abstract:The Tangquan granodioritic pluton in Dalian County, southwestern Fujian, China, which extends in a NE direction with an exposed area of about 130 km2, used to be considered a product of Early Cretaceous magmatism. The present study suggests for the first time that the pluton was formed in the Early Jurassic by using multiple methods for isotopic dating, which give zircon U-Pb ages of 186.8 Ma and 179.0 Ma, Rb-Sr isochron age of 162.02±4.5 Ma, and biotite 40Ar/39Ar plateau age of 158.1±0.7 Ma. The cooling rate for the pluton was relatively low (4.76℃/Ma) during the early stage (183-162 Ma) because of the compressional environment. It was emplaced in a higher cooling rate (50℃/Ma) in an extensional environment during the later stage (162-158 Ma). The granodiorites are metaluminous-peraluminous, relatively enriched in Na2O and depleted in K2O, and characteristic of I-type granites of crust-mantle mixed sources. They are moderately enriched in Rb, Th, Hf and LREE, and depleted in Ti, Nb, Ta and Sr, and
Saday Azadoglu ALIYEVScience , Technology Research , Application Center , Ankara University , Tandogan , Ankara , Turkey , E-mail: sari@eng.ankara.edu.trand Ali SARIDepartment of Geological Engineering , Faculty of Engineering , Ankara University , Tandogan , Ankara , Turkey Zhu Xiling
2003, 77(3).
Abstract:The objective of this study is to determine the geochemical role of molluscs in the distribution of uranium in the marine ecosystem. Biogeochemical studies are carried out on recent mollusc shells from the Caspian Sea, Sea of Japan, Sea of Marmara, Aegean Sea, Black Sea, Mediterranean Sea, Baltic Sea, and Indian Ocean, which differ from each other in terms of physical, chemical, geographic, and geochemical characteristics. In this study, nine Gastropoda and fifty-four Pelecypoda shells of different species are analyzed to document variations of uranium in seasonal layers, which were formed by the seasonal carbonate-organic phase of molluscs during their entire lives. Shell used in this study principally comprises three layers: upper (outer) prismatic, middle prismatic, and inner (mother-of-pearl) layers. In addition, when possible, the head, the middle, and the lower parts of the shells are used for analyses separately. Also, the biological accumulation rate values for each different mollusc species relative to the average uranium value in seawater are calculated. The BAR values of U in mollusc shells range between 11 and 216. Uranium concentrations in recent mollusc shells vary between 0.034 ppm and 0.65 ppm. Organic carbon values vary between 1100 and 9700 ppm in various mollusc species. The uranium and Corg concentrations in living mollusc shells are positively correlated. Both the uranium and Corg contents in mollusc shells are preferably dependent on the taxonomic characteristics of organisms. It has been observed that the uranium concentrations in the mineral-organic phase of molluscs are in good agreement with those of surrounding sediments. Therefore, the changes in the uranium concentrations in shell and sediment types are derived from the uranium concentrations in water.
MENG Xianghua , GE MingInstitute of Sedimentary Basin , China University of Geosciences , Beijing , E-mail: mengxh@cugb.edu.cn Liu Xinzhu , Zhu Xiling
2003, 77(3).
Abstract:This paper gives an account of the research that the authors conducted on the cyclic sequences, events and evolutionary history from Proterozoic to Meso-Cenozoic in the Sino-Korean plate based on the principle of the Cosmos-Earth System. The authors divided this plate into 20 super-cyclic or super-mega-cyclic periods and more than 100 Oort periods. The research focused on important sea flooding events, uplift interruption events, tilting movement events, molar-tooth carbonate events, thermal events, polarity reversal events, karst events, volcanic explosion events and storm events, as well as types of resource areas and paleotectonic evolution. By means of the isochronous theory of the Cosmos-Earth System periodicity and based on long-excentricity and periodicity, the authors elaborately studied the paleogeographic evolution of the aulacogen of the Sino-Korean plate, the oolitic beach platform formation, the development of foreland basin and continental rift valley basin, and reconstructed the evolution of tectonic paleogeography and stratigraphic framework in the Sino-Korean plate in terms of evolutionary maps. Finally, the authors gave a profound discussion on the formation and development of molar-tooth carbonates, phosphorites and source rocks.
YE Jiaren , HAO Fang , CHEN JianyuFaculty of Earth Resources , China University of Geosciences , Wuhan , Hubei , E-mail: jrye@cug.edu.cn Ren Xifei , Zhu Xiling
2003, 77(3).
Abstract:The Damintun depression is one of the four depressions in the Liaohe basin in northern China, and is a rift basin developed in the Paleogene. This paper discusses in detail the characteristics of pressure and fluid potential of the Damintun depression based on a synthesis of the data from boreholes, well tests and seismic surveys. Data from sonic logs, well tests and seismic velocity measurements are used to study the pressure characteristics of the areas. From the sonic log data, shales can be characterized as normally pressured, slightly overpressured or highly overpressured; from the well test data, the pressure-depth gradient in oil-producing intervals implies hydrostatic pressure in general. Most seismic profiles in the Damintun depression are of sufficiently high quality for seismic velocities to be measured. The fluid pressures, excess pressures and pressure coefficients in 47 representative seismic profiles are predicted using formula calculation methods, and further transformed to fluid potentials. The resultant pressure profiles show normal pressure, moderate overpressure and intense overpressure increasing with depth. The pressure evolution can be divided into three stages as initial generation, partial dissipation and re-accumulation. Fluid potential is the principal factor controlling hydrocarbon migration in a reservoir. Its distribution varies with depth; above the T4 interface a gravity-flow dominates, whereas beneath it a compaction flow dominates. The development of overpressure in the Damintun depression has a crucial influence on the distribution of fluid potentials, which agrees with that of overpressure in general. The results of the fluid potential analysis indicate that the areas of Dongshenpu-Xinglongpu and the southwestern part of the depression are most favorable for hydrocarbon migration and accumulation.
2003, 77(3).
Abstract:Emergence of the Late Permian Changhsingian Reefs at theEnd of the PermianWU Yasheng, FAN Jiasong (Institute of Geology andGeophysics, Chinese Academy of Sciences, Beijing 100029);and JIN Yugan (Nanjing Institute of Geology and Paleontology,Chinese Academy of Sciences, Nanjing, Jiangsu 210008)Dolostones occur on the top of the reef core, reef front and backreef sequences of the Upper Permian The Changhsingian reef inZiyun County Guizhou Province, southwestern China.Comprehensive study on them reveals that these dolostones areof the supratidal Sabkha genesis: (1) All have δ~(18)O values higherthan those of their precursor limestones; (2) All have Sr and Fecontents similar to those of known typical supratidal Sabkhaevaporative finely crystalline dolostones from a well in theOrdos Basin, Shanxi-Gansu-Ningxia provinces, China; (3) Allare composed of finely crystalline euhedral-subhedral dolomites;
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