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Chinese Science Bulletin 2001年第4期46卷 330-333页

作者： CHEN Nengsong, SUN Min, ZHANG Kexin & ZHU Yunhaifaculty of earth Sciences, china university of geosciences, wuhan 4.0074. {4. Department of earth Sciences, The university of Hong Kong, Hong Kong SAR, {4. faculty of earth Sciences China University of Geosciences Wuhan China Department of earth Sciences The University of Hong Kong Hong Kong SAR China

Single-grain zircon U-Pb and amphibole 4.Ar-39Ar dating have been conducted on a deformed and metamorphosed diorite in the East Kunlun Orogenic Belt, which intruded into the middle Proterozoic Kuhai Group exposed in the south of Xiangride region, Dulan County, NW Qinghai Province. The zircon gives a concordant U-Pb age of (4.6.5±9.1) Ma. The amphibole yields Ar plateau age of (4.8.0±1.2) Ma and an isochronal age of (4.8.9±5.6) Ma. Age results of both stepwise released Ar and conventional K-Ar analysis are remarkably higher than that of zircon U-Pb, suggesting that the amphibole contains excess argon and the amphibole plateau age cannot be taken as the timing of metamorphism or deformation. The zircon age is interpreted to be crystallization age of the diorite pluton, which suggests that an Early-Paleozoic magmatic zone indeed existed in the East Kunlun Orogenic Belt stretching along the region south to the Golmud, Normuhong and Xiangride.

关键词： East Kunlun Orogenic Belt metadiorite geochronology excess argon.

An Analysis of Groundwater in Sinjar Plain (Northwest of Iraq) Using WQI Model

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Journal of china university of geosciences 2001年第4期12卷 291-295页

作者： Bassam F Al Bassam Ayad M Fadhil faculty of earth Resources , china university of geosciences , wuhan 4.0074 faculty of earth Resources China University of Geosciences Wuhan 430074

Sinjar plain-northwest Iraq has an abundant amount of groundwater. Due to the importance of this water source, the water quality index (WQI) model was used in the classification of groundwater in the western and eastern regions of Sinjar plain for beneficial use. Groundwater samples were chemically analyzed to calculate the values of WQI. This model consists of a single number of the integrated deviation from standard quality, which indicates the relative importance of each relevant variable for beneficial use. The results indicate that the WQI could be used to determine the particular uses of groundwater. The groundwater in the Sinjar plain is more suitable for irrigation than for livestock drinking and domestic use.

关键词： water quality index Sinjar plain groundwater classification.

Sand Dunes Fixation in Baiji District, Iraq

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Journal of china university of geosciences 2002年第1期13卷 67-72页

作者： Ayad Mohammed Fadhilfaculty of earth Resources , china university of geosciences , wuhan 4.0074 faculty of earth Resources China University of Geosciences Wuhan 430074

This study was carried out at Sand Dunes Stabilization Researches Station in Baiji district (230 km north of Baghdad, Iraq) to evaluate the effects of local soil conditioners manufactured from oil derivatives and plant residuals on sand dunes fixation as the first step for sand dunes stabilization. The results indicate that the fuel oil has the first place in improving wind erosion parameters in the study area, such as increasing mean weight diameter, dry aggregates percentage, the needed time for complete disaggregation by dry sieving, and decreasing the disaggregation rates. Bitumen emulsion occupies the second place, while the plant residuals occupies the third place and has slight effects on the studied parameters. Effects of conditioners on natural vegetation cover are negative in oil derivatives treatments, while positive in plants residuals treatments.

关键词： sand dunes fixation soil conditioners wind erosion Iraq.

Geochemistry of Sedimentation and Diagenesis in Qixia Formation (Early Permian) of Badong, Hubei Province, china: Implications for T-R Cycle Interpretation

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Journal of earth Science 1999年第2期18卷 56-62页

作者： Yan Jiaxin Zhao Laishi faculty of earth Sciences, china university of geosciences, wuhan 4.0074.Fang Nianqiao Department of Geology and Mineral Resources, china university of geosciences, Beijing 100083

Combined with sedimentary observation and mineralogical research on a type of drusy celestite of early diagenesis in origin, this geochemical study on the Qixia Formation at the Shuibuya Section, Badong County, Hubei Province of south china evaluates the contribution of sedimentation and diagenesis to the mass fractions of CaO, Al 2O 3, MgO, SiO 2, Fe 2O 3, Na 2O, K 2O, Mn, Sr, P and Ba in the carbonates. The Sr, initially released from the stabilization of carbonate calcium mineral, precipitated with sulfate ion as celestite in early diagenetic environment, where sulfate reduction was the minimum. Then it redistributed in burial diagenetic environment, where celestite was replaced by calcite. The fractions of the MgO and SiO 2 in the carbonates were mainly modified by the early dolomitization and silicification respectively. That of the Na 2O was overprinted by the burial diagenesis. Multivariate statistical analysis on data of sixty bulk rocks indicates that the mass fractions of the Al 2O 3, K 2O, Fe 2O 3, Mn, CaO, P and Ba were affiliated with the sedimentary factor despite the obvious decrease of CaO during early dolomitization and silicification. Among them, the Al 2O 3 and K 2O mainly represent the detrital components. In addition, a dysaerobic sedimentary background was confirmed by trace element measurement and information derived from the formation of the celestite. This genetic discrimination facilitates the interpretation of the transgressive regressive (T R) cycle and specialities featured this unusual carbonate unit.

关键词： sedimentation diagenesis celestite geochemistry T R cycle.

Dynamic Analysis of Yinggehai Basinthrough Analogue Modeling

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Journal of earth Science 2000年第1期19卷 81-85页

作者： Sun Zhen faculty of earth Resources, china university of geosciences, wuhan 4.0074.Zhou Di South {4. Sea Institute of Oceanology, Guangzhou 510301 Zeng Zuoxun faculty of earth Sciences, china university of geosciences, wuhan 4.0074.Zhong Zhi

The Yinggehai basin lies in the northwestern shelf of the South china Sea. The maximum depth of the Cenozoic sediments is 17 km. Present gas exploration was mainly in the Neogene strata. But it is estimated that the Paleocene sediments (~8 km in thickness) has productive potential. So research on the Paleogene rifting structure will greatly enlarge the exploration area. 3D scaled sandbox is the analogue model for the Yinggehai basin. Comparing modeling with the basin by the positions and movement of depocenters, the geometric similarity, we aim to summarize the dynamic situation of Yinggehai basin during the rifting stage and to cast an objective prediction on the structures in the areas without data.

关键词： dynamic analysis rifting structure analogue modeling.

Partial Melting Processes During Exhumation of Ultrahigh-Pressure Metamorphic Rocks in Dabieshan, china

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Journal of earth Science 1999年第3期18卷 194-199页

作者： Zhong Zengqiu Zhang Hongfei Suo Shutian You Zhendong(faculty of earth Sciences, china university of geosciences, wuhan 4.0074. faculty of earth Sciences China University of GeosciencesWuhan 430074

Study practice has proved that the ultrahigh pressure metamorphic rocks iu Dabieshan must have exPerienced botk the retrograde metumorphism and partial melting under decompression and amphibolite-facies conditions during their exhumation from mantel depth to lower-middle *** retrometamorphism and partial melting of the ultrahigh pressure rocks in association with thermal state changing in the middle-lower crust, under amphibolite-facies conditions, are important physical and chemical processes. It would result in a great detrease in the integrated yield strength, and the enhancement of the de formabilitY or the rocks, promoting the transition from contractional (collision) to extensional defoemational regime. The statement of tbe retrometamorphism and partial melting of the ultrahigh pressure rocks has proved the in-site model for the ultrahigh pressure rocks in Dabieshan. It not only clarifies the evolutiou from the UHP eclogite to the surrounding gneissic rock (so called UHP gueiss) and to the garnet-beariug roliated granites (non-UHP country rocks), but also provides scientific arguments for the establiskment of the dynamic model of the exhumation of UHP metamorphic rocks in Dabiesban. In general, Purely conductive heat transfer from the crust itself is probably insurficient to produce temperature conditions for partial melting, and additional heat sources must have been present during partial melting. We infer that the partial melting and extensional flow are probably driveu by delamination and magmatic underplating of thickeued lithospkeric mantle following the continental oblique collision.

关键词： ultrahigh-pressure metamorphic rocks partial melting Dabieshan

Tectonic Evolution of Tertiary Basins in circum-Pacific Belt of china and Their Geodynamic Setting

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Journal of earth Science 1997年第1期16卷 4-10页

作者： Li Sitian Yang Shigong Xie Xinongfaculty of earth Resources, china university of geosciences, wuhan 4.0074.

? Tertiary basins distributed mainly in two zones in the CircumPacific region of china, which includes a rift basin zone in continental area and a continental margin basin zone in offshore area of west Pacific Ocean. Extensional regime dominated the evolution processes of the basins, and in many cases the extensional process was accompanied by dextral strikeslip movement. Mantle upwelling or plumes have been found beneath the rift zone and the marginal sea basins by geophysical and volcanic petrology research. Based upon the regional studies, the basin formation, lithosphere thinning and mantle upwelling may be caused by the superimposed effect of three processes: (1) subduction of Pacific plate, (2) subduction of IndiaAustralia plate which is the main controlling factor for the opening of the South china Sea and (3) collision of India with Eurasia. 

关键词： rifting basin geodynamics mantle upwelling plume.

Peat molecular fossils recording paleoclimatic change and organism replacement

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Chinese Science Bulletin 2001年第20期46卷 1749-1752页

作者： XIE Shucheng & R. P. Evershed1. faculty of earth Science, china university of geosciences, wuhan 4.0074. {4. 2. School of Chemistry, university of Bristol, Bristol, BS8 1TS, UK Correspondence should be addressed to Xie Shucheng (e-mail: scxie@ ***) faculty of earth Science China University of Geosciences Wuhan China School of Chemistry University of Bristol Bristol

The occurrence of the dominant C23 n-alkane derived from bryophyte was demonstrated to be related to the cold climate, based on the GC and GC/MS analyses on a 4.-cm long peat core, in which this compound exponentially varies in abundance with the depth corresponding to the well-known second Little Ice Age. Both the variation of the chemical components of modern bryophyte resulted from climatic change and the ecological data about the biological growth influenced by climate shed light on the point that the variation of this compound in the peat was related to the cold climate. This was also evidenced by the previously-reported lacustrine data. In addition, the variations of the ratios of ketones/esters and C24.n-alkene/n-alkane (C24.1/024.0) display the trend identical with that of organisms, implicating the replacement between bryophyte and monocotyledon occurring in the peat core.

关键词： bryophyte molecular fossil n-alkane paleoclimate Little Ice Age peat lacustrine.

Sm-Nd and zircon SHRIMP U-Pb dating of Huilanshan mafic granulite in the Dabie Mountains and its zircon trace element geochemistry

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Science china earth Sciences 2005年第12期48卷 2081-2091页

作者： HOU Zhenhui1, LI Shuguang1, CHEN Nengsong2, LI Qiuli1 & LIU Xiaoming3 1. School of earth and Space Sciences, university of Science and Technology of china, Hefei 230026, china 2. The Key Laboratory of Continental Dynamics of the Ministry of Education, Northwest university, Xi’an 710069, china 3. faculty of earth Sciences, china university of geosciences, wuhan 4.0074. china 1. School of earth and Space Sciences University of Science and Technology of China 230026 Hefei China 2. The Key Laboratory of Continental Dynamics of the Ministry of Education Northwest University 710069 Xi’an China 3. faculty of earth Sciences China University of Geosciences 430074 Wuhan China

The mafic granulites from Huilanshan are outcropped on the center of the Luotian dome in the northern Dabie Mountains. The Sm-Nd isochron defined by granulite-facies meta-morphic minerals (garnet + clinopyroxene + hypersthene) yields an age of 136 ± 18 Ma indicating the early Cretaceous granulite-facies metamorphism. The cathodoluminescence (CL) images of zircons from the granulite show clearly core-mantle-rim structures. The zircon cores are charac-terized by typical oscillatory zoning and highly HREE enriched patterns, which suggests their magma origin. Some zircon cores among them with little Pb loss give SHRIMP U-Pb ages rang-ing from 753 to 780 Ma, which suggests that the protolith of Huilanshan granulite is Neopro-terozoic mafic rocks. The zircon mantles usually cut across the oscillatory zone of the zircon cores have 3―10 times lower REE, Th, U, Y, Nb and Ta contents than the igneous zircon cores but have high common Pb contents. These characteristics suggest that they were formed by hydrothermal alteration of the igneous zircons. The part of zircon mantles with little Pb loss give a similar SHRIMP U-Pb age (716―780 Ma) to the igneous zircon cores, which implies that the hydrothermal events occurred closely to the magmatic emplacement. In view of the strong early Cretaceous magmatism in the Luotian dome, consequently, the Huilanshan mafic granulite was formed by heating of the Neoproterozoic mafic rocks in mid-low crust, which caused the granu-lite-facies metamorphism underneath the Dabie Mountains. The similarity between the granulite metamorphic age (136 ± 18 Ma) defined by Sm-Nd isochron and K-Ar age of 123―127 Ma given by amphible from the gneiss in Luotian dome suggests a rapid uplifting of the Luotian dome, which may result in further exhumation of the ultrahigh pressure metamorphic rocks in the Dabie Mountains.

关键词： Dabie orogen, granulite, zircon U-Pb ages, Sm-Nd age.

Discovery of Jinning Cycle Magmatism in Eastern Part of Eastern Kunlun Orogenic Belt and Its Significance

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Journal of earth Science 2000年第3期19卷 134-139页

作者： Zhu Yunhai faculty of earth Sciences, china university of geosciences, wuhan 4.0074. {4. Pan Yuanming Department of Geological Sciences, university of Saskatchewan, Saskatoon, Canada Zhang Kexin faculty of earth Sciences, {4. university of G

From the isotopic dating study of gneissic granodiorite, the authors discovered magmatism of the Jinning cycle. Intrusive rocks were formed in the Neoproterozoic, whose Pb Pb ages range from (913±4. Ma to (1 011±4. Ma and U Pb concordia age is (703±15) Ma. The tectonic settings of the rocks are volcanic arc or syn collision. After the formation of the intrusive rocks, these rocks also experienced reconstruction of Caledonian metamorphism. Based on the Ar Ar dating of metamorphic mineral of muscovite, the metamorphic time is determined to range from (386.8±0.8) Ma to (389.4.±3.70) Ma.

关键词： Jinning cycle magmatism Eastern Kunlun orogenic belt Qinghai Province.