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Thermal State and Structure of the Lithosphere beneath eastern china. A Synthesis on Basalt-Borne Xenoliths

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Journal of Earth Science 2010年第5期21卷 711-730页

作者：黄小龙徐义刚 Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences

Application of reliable thermobarometer on garnet-bearing mantle xenoliths and granulite xenoliths entrained by Cenozoic basalts in eastern china.reveals two main types of geotherm. The first type, as exampled by Hannuoba （汉若坝）, Mingxi （明溪） and probably Northeast china. is characterized by constant slope of data in the P-T space. The second type, as exampled by the high geotherms of Niishan （女山） and probably Xinchang （新昌）, is characterized by variable slopes, with the samples with pressure 〈2 MPa defining a slow slope, whereas the samples with pressure 〉2 MPa define a virtually vertical slope. The different slopes in the second type of geotherm may correspond to different heat transfer mechanisms, with conductive transfer for the shallow upper mantle and advective transfer for the deep mantle. This observed transition in thermal transfer mechanism is consistent with theoretical modeling. The two types of geotherm are not mutually exclusive, because the second type may characterize the thermal state of whole lithospheric section including both mechanical boundary layer （MBL） and thermal boundary layer （TBL）, while the first type may only depict the MBL. The variable geotherms for different regions are indicative of a heterogeneous lithospheric structure in eastern china. （a） eastern North china.craton （NCC） is characterized by a second-type geotherm, corresponding to a thin lithosphere （-70 km）. Comparison of the equilibrium temperatures of spinel peridotites with this geotherm constrains the depth to Moho in eastern North china.craton to be 30 kin. In contrast, western NCC （Hannuoba： the first-type geotherm） possesses a relatively low thermal gradient, indicative of a thick lithosphere （〉90-100 km） and a thick crust-mantle transition zone. The dramatic change in crustal and mantle structure across the DTGL （Daxing＇anling （大兴安岭）- Talhangshan （太行山） gravity lineament） is consistent with recent seismic studies. （b） There is a decrease in thermal gradient and in lithosph

关键词： geotherm thermobarometry garnet-bearing peridotite and pyroxenite granulite xenolith lithosphere eastern china.

Typical Oxygen Isotope Profile of Altered Oceanic Crust Recorded in Continental Intraplate Basalts

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Journal of Earth Science 2017年第4期28卷 578-587页

作者： Huan Chen Qun-Ke Xia Etienne Deloule Jannick Ingrin School of Earth Sciences Zhejiang UniversityHangzhou 310027China School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China UMET UMR CNRS 8207Universite de Lillel59655 Villeneuve d'AscqFrance CRPG UMR 7358CNRS Universite de Lorraine54501 Vandoeuvre-les NancyFrance

Recycled oceanic crust （ROC） has long been suggested to be a candidate introducing en- riched geochemical signatures into the mantle source of intraplate basalts. The different parts of oceanic crust are characterized by variable oxygen isotope compositions （δ^18O=3.7‰ to 13.6‰）. To trace the sig- natures of ROC in the mantle source of intraplate basalts, we measured the δ^18O values of clinopyroxene （cpx） phenocrysts in the Cenozoic basalts from the Shuangliao volcanic field, NE china.using secondary ion mass spectrometer （SIMS）. The δ^18O values of the Shuangliao cpx phenocrysts in four basalts ranging from 4.10‰ to 6.73‰ （with average values 5.93‰±0.36‰, 5.95‰±0.30‰0, 5.58‰±=0.66‰e, and 4.55‰±= 0.38‰, respectively） apparently exceed those of normal mantle-derived cpx （5.6‰±0.2‰） and fall in the typical oxygen isotope range of altered oceanic crust. The δ^18O values display the negative correlations with the Eu, Sr anomalies of whole rocks and erupted ages, demonstrating that （1） the ROC is the main enriched component in the mantle source of the Shuangliao basalts and （2） the contributions of ROC var- ied with time. The basalt with the lowest δ^18O value is characterized by a significant K positive anomaly, highest H2O/Ce and Ba/Th ratios, suggesting that the mantle source of basalts with low δ^18O can also in- clude a water-rich sediment component that may be the trigger for partial melting. Considering the continuous subduction of the Pacific slab, the temporal heterogeneity of the source components is likely to be caused by the Pacific slab subduction.

关键词： continental basalt oxygen isotope recycled oceanic crust Pacific slab eastern china.

Delineation of Potential Mineral Resources RegionBased on Geo-anomaly Unit

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Journal of Earth Science 2000年第2期19卷 66-71页

作者： Chen Yongqing Faculty of Earth Resources, china.University of Geosciences, Wuhan 430074 The Center for Development and Research, china.Geological Survey, Beijing 100083 Liu Hongguang Faculty of Earth Resources, china.University of Geosciences, Wuhan 4

The geological anomaly unit method (GAUM) is a new way to delineate and evaluate ore finding targets in line with the “geological anomaly ore finding theory”. Comprehensive ore finding information from geological, geochemical and geophysical data is used for quantitative measurement of the “ore forming geological anomaly unit” in this paper. The main procedures are shown as follows: (1) The geo anomalous events associated with gold mineralization are analyzed in Tongshi gold field; (2) The zonation in the concentrated heavy minerals and the stream sediment elements of ore forming geo anomaly are studied in detail; (3) The deep geological structural framework is deduced by means of the synthetic geological interpretation of gravity and magnetic information; (4) The ore controlling geo anomalies and ore anomalies are chosen as the variables of the favorable ore forming indexes that can be used for the quantitative delineation and evaluation of the potential ore forming regions.

关键词： ore forming geo anomaly unit mineral resources areas comprehensive ore forming information favorable ore forming index Tongshi gold field western Shandong Province eastern china.

Sequence　Stratigraphic　Features　of　Mesozoic－Cenozoic　Nonmarine　Sediments　in　eastern　china

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Journal of Earth Science 1994年第1期13卷 55-64页

作者： Xu Huaida Wei Kuisheng (Departrment of Energy Resources Geology, china.University of Geosciences, Beijing 100083)

The basic concepts of sequence stratigraphy can be applied to any cyclic successions regardless of their origin being marias or nonmarine .The storm base can be taken as the base level at the gentle slope side of a faulted basin for distinguishing the systems tractS as no shelf edge is present in nonmarihe fault6d basins. Most of coatinuous rethetions with high amplitude in seismic sections, misunderstood previously as the boundaries of stratigraphic unit, are maximum flooding surface (MFS)in fact. Abundant and diversified microfossils and nannofossils high content of organic carbon,various authigenic minerals such as glauconie,siderite are concentrated nearby these surfaces. It means that the open sea water invaded iato the faulted basins many times in Cretaceous and Paleogene, which make a restricted environment favourable for oil generation. The trend of lake level changes is similar to that of Haq's curve generally, however, the influence of local movements and autostrahgraphic events have to be colandered. The stratal patterns and models of nonmarine sequence are proposed.

关键词： nonmarine depositional sequence sequence boundary condensed section systems tract model base-level change curve basin floor fan eastern china.

Cu－An　Metallogenic　Series　Related　to　Volcanic－Intrusive　Complexes　in　eastern　china

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Journal of Earth Science 1995年第1期14卷 107-113页

作者： Zhai Yusheng(Department of Geology and Mineral Resources, china.University of Geosciences,Beijing 100083)Yao Shuzhen(Faculty of Earth Resources, china.University Of Geosciences,Wuhan 430074)

The Cu - An co - existence ore deposits related to intermediate- acidic volcanic - intrusive complexes are widespread in eastern china. They can be divided into 5 types: (1) sharn type, (2 )porphyry type, (3)vein type, (4 )breccia pipe type and (5)stratabound type. All of those have intimate spatial, temporal and genetic relations formed by the Mesozoic tertonicmatic - hydrothermal activities in certain geological environments. The magmatic and Cu-An metallogenic ager were predominately in Late Mesozoic (179-90 Ma), and in the period of 150-120 Ma the ore-forming Processes reached the Peak. The main geological Settings of Cu-An ore-forming Processes are: (1) continental margins, including the Peripheral depression of the continental Plate, (2) deep fault zones in the continental Plate,(3)continental rift belt. The magmatic activities were under the combined control of basement fault (s )and superficial fault (s ), and mostly formed the continental volcanic basins. The regional Cu-An metallogenic zones occur along the deep fault zones in WNW - EW direction,such as the Tongling metallogenic subzone, or in NE-NNE direction, such as the Dexing metallogenic subzone. Most of Cu- An ore deposits are related to subvolcanic stocks consist of quartz diorite, granodiorite, quartz porphyry, andesite porphyry, trachyte porphyry and other rocks, which belong to the calc- alkaline series and the I - type granitoid. The spatial zoning of matals from the center to periphery of the stocks is: CU (Mo )→ Cu,Au→Cu, Ph, Zn,An →Ph, Zn, Ag →Ph, Ag. There is a typical venical metallic zoning (from surface to 3 000m in depth ) in Yinshan Cu-An-Ph-Zn-Ag ore deposit, northeastern Jianxi Province.

关键词： Cu-An ore deposit metallogenic series volcanic-intrusive complex,Mesozoic eastern china.

Metallogeny of Shoshonite-Hosted Copper-Gold Deposits in Middle-South Parts of Tancheng-Lujiang Deep Fault Zone and Its Vicinity, eastern china

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Journal of Earth Science 1999年第1期18卷 51-54页

作者： Qiu Jiansheng Wang Dezi Ren Qijiang Department of Earth Sciences, Nanjing University, Nanjing 210093 Brent I. A. McInnes CSIRO Division of Exploration and Mining, PO Box 136, North Ryde, NSW 2113, Australia

The middle south parts of Tancheng Lujiang deep fault zone and its vicinity are an important locality of Cu Au deposits related to Mesozoic volcanic subvolcanic magmatism in eastern china. According to their metallogenic features and ore forming conditions, copper gold deposits in this district are ascribed to two groups: the epithermal group which can be further divided into tellurium gold type, quartz adularia type and quartz manganoansiderite type; the magmatic hydrothermal group which includes porphyry Cu Au deposit, breccia pipe porphyry type Au Cu deposit and skarn type Au Cu deposit. In this paper, characteristics of six typical shoshonite hosted Cu Au deposits are outlined. Additionally, the factors that control the metallogenesis and distribution of these Cu Au deposits are discussed preliminarily.

关键词： shoshonitic volcanic rocks copper gold deposits metallogenic features eastern china.