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Cumulate complex xenoliths in the Early mesozoic.in eastern Inner Mongolia

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Chinese Science Bulletin 1999年第14期44卷 1272-1279页

作者： Ji’an Shao Qingjun Han Luqiao Zhang Baolei Mu Peking Univ Beijing 100871 Peoples R China Acad Sinica Inst Geol Beijing 100029 Peoples R China Geol Inst Inner Mongolia Hohhot 010020 Peoples R China

Mafic xenoliths occur in mesozoic.diorites from nine localities in eastern Inner Mongolia from the Da Hinggan Mrs. to Huabei craton. Their petrologic and geochemical features suggest that they are an intact suite of cumulate complex whose mineral assemblages contain typical patent mantle metasomatism minerals such as pargosite, phlogopite and apatite. Their REEs and trace element characteristics suggest a comagmatic relationship in these cumulates with different compositions. Isotopic dating of the xenoliths indicates that they are products of the mantle magmatic underplating in the Early mesozoic.(237—224 Ma), and they may provide direct evidence for the crust-mantle interaction and vertical accretion of continental crust under a background of the mantle upwelling in the Early mesozoic.in Huabei region.

关键词： cumulate underplating. crust-mantle interaction Early mesozoic. eastern Inner Mongolia.

Characteristics of magnetic fabrics of Jiangshan-Shaoxing collision belt and its tectonic implications

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Chinese Science Bulletin 1999年第19期44卷 1819-1824页

作者： Zhongyue Shen Ying Ye Dajun Fang Xiaodong Tan Zhejiang Univ Dept Earth Sci Hangzhou 310027 Peoples R China

The study of anisotropy of magnetic susceptibility (AMS) of rocks from the northern part of Jiangshan-Shaoxing collisional belt demonstrates that the minimum principal AMS axes are the most concentrated one in various types of rocks. The planar projection of the minimum axis shows that the main compressive stress lies on northwest 30°-60°, which trends domi-nantly in northwest-southeast of Chencai area and arc-like disperse towards both north

关键词： Jiangshan-Shaoxlng collision belt magnetic fabric paleomagnetism. mesozoic.

A remarkable new genus of Cretaceous dustywings(Neuroptera: Coniopterygidae) in amber from northern Myanmar

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Zoological Systematics 2017年第3期42卷 380-389页

作者： Xingyue Liu Xiumei Lu Department of Entomology China Agricultural University

A new dustywing genus and species, namely Cretaconiopteryx grandis gen. ＆ sp. nov., from the mid-Cretaceous amber of Myanmar is herein described in the lacewing family Coniopterygidae. The new genus is distinguished from all other dustywing species by the combination of following morphological features： relatively large body-size, comparatively rich crossvenation, origin of RP＋MA near wing base in both fore-and hindwing, forewing RA and RP terminally fused into a loop, and proximally zig-zagged forewing Cu P. A new subfamily, Cretaconiopteryginae subfam. nov., is erected based on this spectacular new genus. The new subfamily might represent the basalmost lineage of known coniopterygids.

关键词： Neuropterida taxonomy new species Burmese amber mesozoic.

Geological and geochemical character and genesis of the Jinlongshan-Qiuling gold deposits in Qinling orogen: Metallogenic mechanism of the Qinling-pattern Carlin-type gold deposits

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Science China Earth Sciences 2000年第S1期43卷 95-107页

作者：张复新陈衍景李超张静马建秦李欣 Department of Geology Northwest UniversityXi’an 710069China Department of Geology Peking UniversityBeijing 100871China Xi’an Road Traffic University Xi’an 710054China Guiyang Institute of Geochemistry Chinese Academy of SciencesGuiyang 550002China

The Qinling Carlin-type gold deposit belt is the second largest Carlin-type gold ore concentrated area in the world and occurs in mesozoic.intracontinental collisional orogen, contrasting to the Carlin-type gold deposits in the Basin and Range province in Cenozoic active continental margin of West America. With ore-forming ages focussed at the range of 197.45-129.45 Ma, its metallogenic geodynamic background was the decornpression-pyrogenation regime at the transition stage from collisional compression to extension, indicating that gold mineralization synchronized with the mesozoic.continental collision. Geochemical studies discover that ore fluids and materials mainly came from the Hercynian-lndosinian tectonic layer. mesozoic.intracontinental subduction of Hercynian-lndosinian association along the Shuanghe-Gongguan fault led to the formation of Jinlongshan-Qiuling gold deposits. Accordingly, the tectonic metallogenic model is established for Qinling-pattern Carlin-type gold deposits.

关键词： Qinling orogen Carlin-type gold deposit tectonic metallogenic model collisional orogenesis mesozoic.

Metallogenic geodynamic background of mesozoic.gold deposits in granite-greenstone terrains of North China Craton

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Science China Earth Sciences 1998年第2期41卷 113-120页

作者：陈衍景郭光军李欣

The spatial distribution map of 65 mid-large gold-deposits hosted in the granite-greenstone terrains of the North China Craton is first drawn. These gold deposits mainly concentrate in the mesozoic.remobilized Yinshan-Yanshan-Liaoning-Jilin intracontinental collisional orogenic belt, the northern Qinling and the Jiaodong mesozoic.collisional orogenic belts, and the mesozoic.intracontinental fault-magmatic belts developed along the Taihangshan and the Tan-Lu faults; their mineralizing time is predominantly Jurassic-Cretaceous, i.e. the Yanshanian. The metallogenic geodynamic background is exactly the compression-to-extension transition regime during continental collision.

关键词： North China Craton gold deposit granite-greenstone terrain collision orogenesis mesozoic.