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Discovery and analysis of ultra-micro grinding grain texture in slipping lamellae of ductile-brittle zone

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Science china earth sciences 2004年第3期47卷 265-271页

作者： GE Heping1, SUN Yan1, LU Xiancai1, ZHU Wenbin1, GUO Jichun1, LIU Deliang2 & Chi-yuen Wang3 1. department of earth sciences, nanjing university, state key laboratory of mineral Deposit, nanjing 210093, china 2. department of earth and Space sciences, university of Science and Technology of china, Hefei 230026, china 3. department of Geology and Geophysics, university of California, Berkeley, CA 94720, USA department of earth sciences Nanjing University State Key Lab. of Mineral Deposit Nanjing 210093 China Dept. of earth and Space sciences Univ. of Science/Technology of China Hefei 230026 China department of Geology and Geophysics University of California Berkeley CA 94720 United States

Based on the observation of the deep bore cores sampled from the state of Cali-fornia, USA, preferred arranged particulate concentration belts were found in the ultra-slipping lamellae. And the same phenomenon was found again later in the bore cores from the petroleum basin in the Northern Shaanxi Province. It may be the product of the dynamic processes involv-ing tumbling, grinding and compresso-shearing functions, so the spherical particulates with ul-tra-size of nm and mm are called grinding grain. The formation of the grinding grains is related with the ductile-brittle deformation, the lateral pressure of the slipping, and the very low grade of dynamic metamorphism of the rocks. Based on the systematic analysis, it is indicated that some elements like Nb and Ta are enriched in the grinding grains in the granitic rocks because of the chemical differentiation, and that the slipping lamellae bearing grinding grains in mudstone with smear efficiency prove a perfect seal for oil and gas reservoirs. Meanwhile, the paper provides bases for the studies on the fast stick-slip movement and shear paradigm.

关键词： slipping lamellae, grinding grain texture, ductile-brittle deformation, smear efficiency.

Environmental archaeology of the Dachang region in the Daning Valley,the Three Gorges reservoir region of the Yangtze River,china

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Chinese Science Bulletin 2008年第S1期53卷 140-152页

作者： ZHANG Yun 1 &ZHU Cheng 2 1 state key laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of sciences,Beijing 100093, china 2 School of Geographic and Oceanographic sciences,nanjing university,nanjing 210093,china state key laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing China School of Geographic and Oceanographic sciences Nanjing University Nanjing China

Environmental archaeology of archaeological sites on both sides of the Dachang section in the Daning River,the Three Gorges of the Yangtze River,shows that riverbed evolution has a great influence on the distribution of archaeological sites during the prehistorical and historical period,and it restricts human activity and the development of ancient *** investigation,dating data,paleocurrent analysis of 100 gravels on the riverbed and archaeological excavation reveal that the riverbed of the Dachang section developed in the Shuangyantang region during the early stage,after about 30 kaBP it shifted westward gradually and reached the present *** with the westward shift,the focus of ancient culture changed for several *** the Western Zhou Dynasty's period,the east riverbank of the Daning River was the main residential *** the Han Dynasty,along with the westward shift,the living space of ancient people was no longer confined to the east riverbank and the focus of culture moved *** the Zhangjiawan site became the main dwelling *** the late Han Dynasty, the villages were flooded and the ancients had to immigrate to a high *** of the Han and the Jin Dynasties outcropped on the flood plain of the east bank because their surface sediments were eroded by several flood events and the westward shift of the riverbed.

关键词： the Daning River environmental archaeology the Shuangyantang site the Zhangjiawan site tombs of the Han and the Jin Dynasties

A Study of Sr, Nd and O Isotopes of the K-rich Melanocratic Dykes in the Late Mesozoic Gold Field in the Jiaodong Peninsula

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Acta Geologica Sinica(English Edition) 2001年第4期75卷 432-444页

作者： SUN Jinggui, HU Shouxi, LIU Jianmin, SHEN Kun and LING Hongfei earth Science Institute, Jilin university, Changchun 130062 state key laboratory of research on Metallogenesis of Endogenic Ore deposits,nanjing university, nanjing 210093 Institute of Geology and Geophysics, Chinese Academy of sciences, Beijing 100101 Shandong Institute and laboratory of Geological sciences, Jinan 250013 Jilin Univ Inst Earth Sci Changchun 130062 Peoples R China nanjing Univ State Key Lab Res Metallogenesis Endogen Ore Depo Nanjing 210093 Peoples R China Chinese Acad Sci Inst Geol & Geophys Beijing 100101 Peoples R China Shandong Inst Jinan 250013 Peoples R China Lab Geol Sci Jinan 250013 Peoples R China

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),=0.70895-0.71140) and low (143Nd/144Nd)1 ratios (varying from 0.51135 to 0.51231); and its δ18Osmow, whole rock values vary from +5.8%c to +10.6%c with a mean of +7.1%c. 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 enriched mantle in its mature stage in the back-arc spreading environment. The evolution of magmas is associated with two trends, i.e., fractional crystallization and mixing with or intensive contamination by palaeo-crust materials or metamorphic rocks. The former process is evident in the gold field system of quartz-vein type, whereas the latter is dominated in the gold field system of the altered-rock type. This conclusion is very important for more detailed study of petrogenesis and mineralization through the crust-mantle interaction (exchange) in the Mesozoic in this region.

关键词： late Mesozoic K-rich melanocratic dykes Sr Nd and O isotope geochemistry gold field system in the Jiaodong Peninsula

Leaching experiment research on host rocks of Qiaogashan gold deposit in Shanshan County, Xinjiang, china

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Chinese Science Bulletin 1999年第S2期44卷 216-218页

作者： ZHAI Wei, YANG Rongyong, LI Zhaolin and WU Jianjun department of earth sciences, Zhougshan university, Guangzhou 510275, china state key Laborntory of Metallogenesis, nanjing university, nanjing 210093, china

1 Geological setting of the deposit THE Qiaogashan gold deposit is located at contact zone of middle Tianshan terrance and south Tianshanback-arc basin, and near the latter side. The orebodies are controlled by middle Tianshan brittle-ductileshear zone. The main ore types are auriferous quartz veins and fractured and alterated rocks. The southpart of the deposit is hosted in striking sheared Devonian rocks, while the north part in a diorite body,which was deformed by a nape shear zone. 2 Geology and geochemistry of host rocks The host rocks of south part of the deposit are Devonian detrital stone of terrigenous origin, interlayering volcanic detrial stone of back-arc basin facies, which locally suffered intensive ductile-brittle shearing. The rock type is composed mainly of gray-green siltstone, poststone, metasiltstone, etc., and a se-

关键词： leaching experiment host rocks Qiaogashan gold deposit Xinjiang.

The developmental trend of labrum and median eyes of Orsten-type preserved Phosphatocopina (Crustacea)

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Science china earth sciences 2010年第1期53卷 18-26页

作者： LIU Zheng 1,2 & DONG XiPing 1,2 1 School of earth and Space sciences,Peking university,Beijing 100871,china 2 state key laboratory of Palaeobiology and Stratigraphy,nanjing Institute of Geology and Palaeontology,Chinese Academy of sciences,nanjing 210008,china School of earth and Space sciences Peking University Beijing China state key laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing China

The Phosphatocopina (Crustacea,Arthropoda) is an important group of 'Orsten-type' preserved *** is resolved as the sister-group of *** we study the labrum,the median eyes,and the inner lamella of Phosphatocopina based on the selected specimens respectively from western Hunan,South china,and *** labrum characters of different species exhibit interspecific *** ratio of labrum length/shield length is significant to the reconstruction of the ontogeny of *** labrum characters should be introduced to the diagnosis of *** the earliest growth stage,the median eyes were inconspicuous,almost as flat as the other area of the ***,with the growth of the individuals they became *** were two obviously concave structures on the ventral side of the hypostome in later stages,which were the positions where the median eyes should have been *** addition,the two modes of preservation of the inner lamella,i.e.,that of shrinking and that of bulging up,are interpreted as the preservational artifact herein.

关键词： Phosphatocopina Crustacea Orsten-type preservation morphology ontogeny Cambrian South china Sweden

Petrogenesis and significance of early Yanshanian syenite-granite complex in eastern Nanling Range

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Science china earth sciences 2005年第7期48卷 912-924页

作者： CHEN Peirong1, ZHOU Xinmin1, ZHANG Wenlan1, LI Huimin2, FAN Chunfang1, SUN Tao1, CHEN Weifeng1 & ZHANG Min1 1. state key laboratory of mineral deposits research, department of earth sciences, nanjing university, nanjing 210093, china 2. Tianjin Institute of Geology and mineral Resources, china Geological Survey, Tianjin 300170, china state key laboratory of mineral deposits research Department of Earth Sciences Nanjing University Nanjing 210093 China Tianjin Institute of Geology and mineral Resources China Geological Survey Tianjin 300170 China

In the eastern Nanling Range there exists the early Yanshanian syenite-granite assemblage. A representative example is the Pitou-Tabei complex composed of the Tabei syenite pluton and the Pitou syenogranite pluton in southern Jiangxi Province. U-Pb zircon dating yields ages of 188.6±2.2 Ma for the Tabei pluton and 186.3±1.1 Ma for the Pitou pluton. The Tabei syenite is characterized by relatively low SiO2 content (62.40% - 68.75%), high alkalis (K2O+Na2O = 10.56%-11.96%), low percent K2O/Na2O ratios (0.56-0.93), metaluminous fea- ture (A/CNK = 0.80-1.00), enrichment in LILE (Rb, Ba, K) and HFSE (Th, U, Nb, Ta, Zr, and so on), weakly negative to positive Eu anomalies (δ Eu = 0.63-1.82), relatively low (87Sr/86Sr)i (0.70412-0.70543), and relatively high ε Nd(t) (3.14-3.52). The Pitou syenogranite is charac- terized by high silicon content (SiO2 = 71.06%-76.28%), relatively low alkalis (K2O+Na2O = 8.10%-9.80%), high percent K2O/Na2O ratios (1.22-1.94), metaluminous feature (A/CNK = 0.94-1.07), enrichment in Rb, Th (U), K, depletion in Ba, Nb, Ta, Sr, P , Zr, Ti, high ΣREE (av- eraging 451.03 μg/g), strong negative Eu anomalies (δ Eu = 0.27-0.33), relatively high (87Sr/86Sr)i (0.70805-0.70912), and relatively low ε Nd( t ) (?5.35-?6.29). The Tabei syenite and Pitou syenogranite both have the characteristics of A-type granites. The former is considered to be from the asthenosphere mantle, and the latter was the product of the crust-mantle mixture. They both were probably formed in a rifting setting.

关键词： syenite-granite assemblage single zircon U-Pb age rifting environment Nanling Range.

The history of crustal uplift and metamorphic evolution of Panzhihua-Xichang micro-palaeoland, SW china:Constraints on Sm-Nd, ^(40)Ar/^(39)Ar and FT ages of granulites

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Science china earth sciences 2004年第8期47卷 689-703页

作者： XU Shijin1, LIU Wenzhong1, WANG Rucheng1, YU Hangbo1, LI Daming2, WAN Jinglin2 & FANG Zhong1 1. department of earth sciences and state key laboratory for mineral deposits research, nanjing university, nanjing 210093, china 2. Institute of Geology, china Seismological Bureau, Beijing 100029, china department of earth sciences and state key laboratory for mineral deposits research Nanjing University Nanjing China Institute of Geology China Seismological Bureau Beijing China

Panzhihua-Xichang (Panxi) micro-palaeoland is the oldest terrane on the western margin of the Yangtze Block. Some intermediate-basic granulites are considered to be the crys-talline basement of lower crust in the terrane. Granulite-facies metamorphism of the granulites was developed in the period from 1186 Ma to 1128 Ma. The origin of granulites was related to the collision orogenic process occurring when the micro-palaeolands merged to form the Rodinia Supercontinent. Amphibolite-facies retrogressive metamorphism of granulites took place in the period from 877 Ma to 825 Ma. This period was consistent with the breakup time of the Rodinia Supercontinent. 40Ar/39Ar ages and fission track (FT) ages of granulites in the Panxi mi-cro-palaeoland show that the vertical movement history of crustal rocks was a slow uplift process of the rigid terrane in the time from Neoproterozoic to Mesozoic. The subduction of India Plate towards Euroasia Plate resulted in the rapid uplift of the Qinghai-Tibetan Block in Cenozoic. Meanwhile, the Qinghai-Tibetan Block moved towards east. Consequently the Panxi terrane was uplifted rapidly. As a result of the collision orogeny between the Qinghai-Tibetan Block and the Panxi terrane, the granulite-facies crystalline basement in this region was exhumed and exposed to the surface.

关键词： granulite,isotope geochronology,crustal uplift movement,Panzhihua-Xichang region,western margin of Yangtze Block.

THE STUDY ON PHOSPHORUS RICH ZIRCON FROM THE YASHAN TOPAZ-LEPIDOLITE GRANITE, JIANGXI PROVINCE,SOUTH china

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南京大学学报(自然科学) 1999年第6期 121-124页

作者： Huang Xiaolong Wang Rucheng Liu Changshi ** Chen Xiaoming Zhang Wenlan Lai Mingyuan (state key laboratory of mineral Deposit research, department of earth sciences, nanjing university, 210093,nanjing,PRC)

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关键词： P rich zircon Al 3+ P 5+ Si 4+ 2 Substitution P 5+ Al 3+ Si 4+ -1 Zr 4+ -1 substitution

Transition from platemargin to intraplate environment: Geochemistry of basalts in Paleogene Liaohe basin, northeastern china

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Science china earth sciences 2005年第12期48卷 2069-2080页

作者： WU Changzhi1, GU Lianxing1, REN Zuowei1,2, ZHANG Zunzhong1, CHEN Zhenyan2 & ZHAO Ming1 1. state key laboratory of mineral Deposit research (nanjing university), department of earth sciences, nanjing university, nanjing 210093, china 2. Exploration and Development research Institute of Liaohe Oilfield Branch Company, Petrochina, Panjin 124010, china state key laboratory of mineral Deposit research (nanjing university) Department of Earth Sciences Nanjing University Nanjing China Exploration and Development research Institute of Liaohe Oilfield Branch Company PetroChina Panjin China

Paleogene basalts from the Liaohe basin, northeastern china, are dominated by alkaline olivine basalts and olivine basalts. These basalts are generally enriched in high field strength elements (HFSE), depleted in large ion lithophile elements (LILE) and comparable to those of typical ocean island basalts (OIB). Positive anomalies of Ba, Sr and Zr with high Nb/U, U/Pb, Ce/Pb and Zr/Hf ratios imply that materials from an oceanic crust had been added to the mantle sources of the basalts. In addition, the basalts are generally depleted in Sr, Nd and Pb isotopes, indicating that an enriched mantle (EMI) and a depleted mantle (DM) sources were added to the OIB-like resource. Comprehensive research on lithosphere evolution and tectonic setting of the Liaohe basin and surrounding areas suggests that these basalts were derived by variable degrees of partial melt-ing from an upwelling asthenosphere mantle. Materials from an oceanic lithosphere were added to the source in company with Paleogene tectonic transition from platemargin to intraplate envi-ronment. Retreating and steepening of the subducting Pacific oceanic plate could be the main cause for the tectonic environment transition.

关键词： geochemistry, basalt, Paleogene, Liaohe basin, North china Block, eastern china.