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Science China Earth Sciences 2011年第7期54卷 975-981页

作者： WANG Tao WANG ZongQi yan Zhen yan quanren ZHANG YingLi XIANG ZhongJin Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing 100037 China

The Dabao Formation in the South Qinling Orogenic Belt was previously regarded as Ordovician in age and consists of clastic matrix and blocks of siltstone,limestone,chert,and volcanic ***,some Middle Devonian corals,conodonts,and other fossil fragments within the limestone blocks were discovered in recent field investigations,indicating that the Dabao Formation was formed during late *** with other regional geological data,the Dabao Formation in the Southern Qinling Orogenic Belt is considered to be a late Paleozoic or early Mesozoic accretionary complex.

关键词：秦岭造山带晚古生代构造块体化石中泥盆世地质资料粉砂岩奥陶纪

Equilibrium between Clinopyroxene and Host Rocks:Implication for the Magmatic Source and Evolution of Alkali Basalts of the Taohekou Formation in the Northern Daba Mountains,China

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Acta Geologica Sinica(English Edition) 2011年第1期85卷 145-163页

作者： XIANG Zhongjin yan quanren yan Zhen WANG Zongqi WANG Tao ZHANG Yingli QIN Xiaofeng Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing 100037 China

The Taohekou Formation is a volcanic-sedimentary terrane formed in the early Silurian in the northern Daba Mountains, China. The volcanic rocks, with dominant alkali basalts and minor mantle xenoliths, are enriched in clinopyroxene phenocrysts. Geochemical analysis shows that the composition of clinopyroxenes from different lithofacies has a close affinity. There is a liner correlation present in composition of clinopyroxenes （including phenocryst, microcrystal and xenocryst） from coarse porphyritic basalts, pillow or fine porphyritic basalts to amygdaloidal basalts. All the cllnopyroxenes, except the clinopyroxenes in mantle xenoliths, show a similar pattern of trace elements and REE, which indicates that they are likely products of successive fractional crystallization from cognate magma. Clinopyroxenes in mantle xenoliths, however, are mantle xenocrysts. The crystallization pressure of clinopyroxenes gradually decreases from mantle xenolith, deep-seated xenocryst, coarse porphritic basalts, pillow or fine porphritic basalts, to amygdaloidal basalts, which are 1.92-4.41 GPa, 1.18-2.36 GPa, 1.13-2.05 GPa, 0.44-0.62 GPa and 0.14-0.28 GPa respectively. Calculation results suggest that the primary magma originated from a mantle region deeper than 68 km and stagnates in intervals of 37-68 kin, 15-20 km and 5-9 km during its ascent. The alkali basalts are characterized by increasing concentrations of Si and alkaline with the magmatic evolution. Meanwhile, they are markedly enriched in LREE, and the patterns of trace elements and REE are similar to those of oceanic island basalts.

关键词： clinopyroxene alkali basalt temperature and pressure of crystallization magmaticevolution northern Daba Mountains

Re-Os and U-Pb Geochronology of the Erlihe Pb-Zn Deposit,Qinling Orogenic Belt,Central China,and Constraints on Its Deposit Genesis

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Acta Geologica Sinica(English Edition) 2011年第3期85卷 673-682页

作者： ZHANG Fan LIU Shuwen LI Qiugen SUN Yali WANG Zongqi yan quanren yan Zhen Key Laboratory of Orogenic Belt and Crustal Evolution Ministry of Education Peking University Beo＇ing 100871 China Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China Institute of Mineral Resources Chinese Academy of Geological Sciences Beo＇ing 10003 7 China Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China

The Erlihe Pb-Zn deposit is an important mine of the Pb-Zn metallogenic zone in the South Qinling *** has been considered a sedimentary exhalative deposit in previous investigations because the ore body occurs concordantly at the transitional location of an upright *** and Os isotopic analyses for paragenetic pyrites with sphalerite and galena from the ore body have been used to determine the timing of mineralization and to trace the source of metallogenic *** Re-Os isotopic data of four pyrite samples construct an isochron,yielding a weighted average age of 226±17 Ma（mean square weighted deviation=1.7）,which is considered the main mineralization age.A dioritic porphyrite vein sample,showing weaker mineralization,was also dated using the SHRIMP zircon UPb isotopic method to constrain the youngest metallogenic age of the ore deposit,because it distributes along a group of tensional joints cutting not only the upright fold in the deposit field,but also the main ore *** dioritic porphyrite sample yields a weighted mean ^（206）Pb/^（238）U age of 221±3 Ma,which is slightly younger than the Re-Os isotopic isochron age of the pyrites,considered as the upper age limit of the mineralization,namely the ending age of the *** Os isotopic compositions of sulfide minerals distribute within a range between Os isotopic compositions of the crust and the mantle, indicating that the ore deposit can be derived from magma-related fluid,and the metallogenic materials are most likely derived from the mixing source of the crust and the *** Erlihe Pb-Zn deposit and associated dioritic porphyrite vein,important records of Qinling tectonic-magmatism-mineralization activities,were formed during the Triassic collisional orogeny processes.

关键词： Erlihe Pb-Zn deposit Re-Os isotopic system dioritic porphyrite vein SHRIMP zircon UPb age Qinling Orogen

Indosinian Tectonic Setting of the Southern Yidun Arc: Constraints from SHRIMP Zircon Chronology and Geochemistry of Dioritic Porphyries and Granites

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Acta Geologica Sinica(English Edition) 2006年第3期80卷 387-399页

作者： LIU Shuwen WANG Zongqi yan quanren LI Qiugen ZHANG Dehui The Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education School of Earth and Space Sciences Peking University Beijing 100871 Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China University of Geosciences Beijing 100083

A mass of granitoid and dioritic intrusions are distributed in the southern Yidun Arc, among which the representative Indosinian intrusions include the Dongco and Maxionggou granitoid intrusions in Daocheng County and hypabyssal intrusions intruding into arc volcanic rocks near the Xiangcheng town. The Dongco and Maxionggou granitoid intrusions consist mainly of porphyraceous monzogranites, megacryst monzogranites and aplite granites. The Xiangcheng hypabyssal intrusions are composed dominantly of dioritic porphyries. SHRIMP zircon ages of 224±3 Ma and 222±3 Ma have been obtained for the Dongco granitoid intrusion and the Xiangcheng dioritic porphyries, respectively. The Xiongcheng dioritic porphyries show a calc-alkaline geochemical feature, and are characterized by higher Sr/Y ratios, depletive Nb, Ta, P and Ti, enriched LILEs, and lower εNd （t）（=-3.27）, suggesting that they might be derived from mantle source magmas that were obviously contaminated by continent crustal materials. However, the Dongco and Maxionggou granitoids belong to high-potassium calcalkaline series with a per-metaluminous feature, and are characterized by higher CaO/（∑FeO＋MgO） and Al2O3/（∑FeO＋ MgO） ratios, lower （La/Yb）n and Sr/Y ratios, depletive Nb, Ta, Sr, P and Ti, enriched LILEs, and very low εNd （t）（=-8.10）, indicating that the granitoids might be derived from partial melting of continental crust materials mainly of graywacke. Petrogenesis of Dongco and Maxionggou granitoids implies that there was an oceanic crust between the Zongza continental block （ZCB） and western margin of the yangtze Craton （WMYZC）. And the oceanic crust slab subducted westward during the Indosinian Epoch, producing an Andes-type continent marginal arc and a backarc basin at the WMSCC. Then the oceanic basin closed and a sinistrally lateral collision occurred at ca. 224 Ma-222 Ma between the ZCB and the WMYZC, causing partial melting of sediments in the back-arc basin to generate granitoid magmas of the Dongco a

关键词： southern Yidun Arc dioritic porphyries and monzogranites SHRIMP zircon age,geochemistry and Nd isotope petrogenesis and geodynamics

Zircon U-Pb and geochemical analyses for leucocratic intrusive rocks in pillow lavas in the Danfeng Group,north Qinling Mountains,China

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Science China Earth Sciences 2008年第2期51卷 249-262页

作者： yan quanren Chen JunLu Wang ZongQi yan Zhen Wang Tao Li QiuGen Zhang ZongQing Jiang ChunFa Institute of Geology Chinese Academy of Geological Sciences (CAGS) Beijing 100037 China Beijing SHRIMP Center CAGS Beijing 100037 China Xi’an Institute of Geology and Mineral Resources China Geological Survey Xi’an 710054 China

Field observation showed that there are many irregular leucocratic intrusive rocks in pillow lavas in the Danfeng Group in the Xiaowangjian area, north Qinling orogenic belt. Photomicrographs indicated that the protoliths of those altered leucocratic intrusive rocks are dioritic rocks. Geochemical analyses showed that pillow lavas have a range of SiO2 from 47.35% to 51.20%, low abundance of TiO2 from 0.97% to 1.72%, and percentages of MgO (MgO#=41―49). Chondrite-normalized REE patterns of pillow lavas are even, indicative of a weak differentiation between LREE and HREE (La/YbN=1.52―0.99). N-MORB-normalized trace element abundances showed that pillow lavas are enriched in incompatible elements (e.g., K, Rb, and Ba). Leucocratic intrusive rocks in pillow lavas have a wide range of SiO2 from 53.85%―67.20%, low abundances of TiO2 from 0.51%―1.10%, and MgO (MgO#=40―51), and higher percentages of Al2O3 (13.32%―16.62%) and concentration of Sr (342-539 μg/g), ratios of Na2O/K2O (2―7) and Sr/Y (17―28). Chondrite-normalized REE patterns of leucocratic intrusive rocks showed highly differentiation between LREE and HREE (La/YbN=12.26―19.41). N-MORB-normalized trace element abundances showed that leucocratic intrusive rocks are enriched in incompatible elements (e.g., K, Rb, and Ba), and significantly depleted in HFSE (e.g., Nb, Ta, Zr and Ti), indicative of a relationship to subduction. Isotopically, leucocratic intrusive rocks have a similar εNd(t) (+7.45―+13.14) to that of MORB (+8.8―+9.7), which indicates that those leucocratic intrusive rocks sourced from depleted mantle most likely. SHRIMP U-Pb analyses for zircon showed that those leucocratic intrusive rocks were formed at 442±7 Ma, yielding an age of subduction in the early Paleozoic in the north Qinling orogenic belt.

关键词： Danfeng Group pillow lava leucocratic intrusive rock geochemistry and isotope SHRIMP U-Pb dating

Ages of the Laocheng Granitoids and Crustal Growth in the South Qinling Tectonic Domain,Central China:Zircon U-Pb and Lu-Hf Isotopic Constraints

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Acta Geologica Sinica(English Edition) 2011年第4期85卷 854-869页

作者： yanG Pengtao LIU Shuwen LI Qiugen ZHANG Fan WANG Zongqi WANG Dongsheng WANG Ruiting yan quanren yan Zhen The Key Laboratory of Orogenic Belts and Crustal Evolution Peking UniversityBeijing 100871 Institute of Mineral Resources Chinese Academy of Geological SciencesBeijing 100037 Northwest Geological Exploration and Mining Bureau for Nonferrous Metals Xi＇anShaanxi 710054 Institute of Geology Chinese Academy of Geological SciencesBeijing 100037

The Laocheng granitoid pluton is located in the South Qinling tectonic domain of the Qinling orogenic belt,southern Shaanxi Province,and consists chiefly of quartz diorite,granodiorite and monzogranite.A LA-ICP-MS zircon U-Pb isotopic dating,in conjunction with cathodoluminescence images,reveals that the quartz diorite and granodiorite were emplaced from 220 Ma to 216 Ma,while the monzogranite was emplaced at～210 ***-situ zircon Hf isotopic analyses show that theε_（Hf）（t） values of the quartz diorite and granodiorite range from-8.1 to ＋1.3,and single-stage Hf model ages from 809 Ma to 1171 Ma,while theε_（Hf）（t）values of the monzogranite are-14.5 to ＋16.7 and single-stage Hf model ages from 189 Ma to 1424 *** Hf isotopic features reveal that the quartz diorite, granodiorite and monzogranite were formed from the mixing of the magmas derived from partial melting of the depleted mantle and the lower continent crustal materials,and there were two stages of continental crust growth during the Neoproterozoic（～800 Ma）and Indosinian（～210 Ma）eras, respectively,in the south Qinling tectonic domain of the Qinling orogrnic belt,Central China.

关键词： Laocheng granitoid pluton LA-MC-ICP-MS zircon U-Pb dating zircon Hf isotopes petrogenesis south Qinling tectonic domain

SHRIMP zircon U-Pb dating for volcanic rocks of the Dasi Formation in southeast Hubei Province,middle-lower reaches of the yangtze River and its implications

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Chinese Science Bulletin 2006年第24期51卷 3000-3009页

作者： XIE Guiqing MAO Jingwen LI Ruiling ZHOU Shaodong YE Huishou yan quanren ZHANG Zusong State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China Institute of Mineral Resources Chinese-Academy of Geological Sciences Beijing 100037 China Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China No. 4 Geological Party of Hubei Province Xianning 437100 China Institute of Geology Chinese Academy of Geosciences Beijing 100037 China Southeast Hubei Geological Party of Hubei Province Daye 435100China

The Jinniu Basin in southeast Hubei,located at the westernmost part of middle-lower val-ley of the yangtze River,is one of the important vol-canic basins in East China. Volcanic rocks in the Jin-niu Basin are distributed mainly in the Majiashan Formation,the Lingxiang Formation and the Dasi Formation,consisting of rhyolite,basalt and basaltic andesite,(trachy)-basalt and basaltic trachy-andesite and (trachy)-andesite and (trachy)-dacite and rhyolite respectively,in which the Dasi volcanism is volumet-rically dominant and widespread. The Dasi volcanic rocks were selected for SHRIMP zircon U-Pb dating to confirm the timing of volcanism. The results indi-cate that there exist a large amount of magmatic zir-cons characterized by high U and Th contents in the volcanic rocks. The concordia ages for 13 points are 128 ± 1Ma (MSWD = 3.0). On account of the shape of zircons and Th/U ratios,this age is considered to represent the crystallization time of the Dasi volcan-ism. The volcanic rocks in the Dasi,Majiashan and Lingxiang Formations share similar trace elementand REE partition patterns as well as Sr-Nd isotopic compositions. In combination with the regional geol-ogy,it is proposed that the southeast Hubei volcanic rocks were formed mainly during the Early Creta-ceous,just like other volcanic basins in middle-lower yangtze valley. A lithospheric extension is also sug-gested for tectonic regime in this region in the Cre-taceous Period.

关键词：火山岩 SHRIMP锆石U-Pb测年湖北东南部地质构造年代学长江中下游地区

SHRIMP Zircon U-Pb and Molybdenite Re-Os Datings of the Superlarge Donggou Porphyry Molybdenum Deposit in the East Qinling,China,and Its Geological Implications

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Acta Geologica Sinica(English Edition) 2008年第1期82卷 134-145页

作者： YE Huishou MAO Jingwen LI Yongfeng GUO Baojian ZHANG Changqing LIU Jun yan quanren LIU Guoyin Institute of Mineral Resources Chinese Academy of Geological Sciences 26 Baiwanzhuang Road Beijing 100037 China University of Geosciences Beijing 100083 Beijing SHRIMP Center Institute of Geology Chinese Academy of Geological Sciences Beijing 100037

Located in the eastern part of the East Qinling molybdenum belt, the Donggou deposit is a superlarge porphyry molybdenum deposit discovered in recent years. The authors performed highly precise dating of the mineralized porphyry and ores in the Donggou molybdenum deposit. A SHRIMP U-Pb zircon dating of the Donggou aluminous A-type granite-porphyry gave a rock-forming age of 112±1 Ma, and the ICP-MS Re-Os analyses of molybdenite from the molybdenum deposit yielded ReOs model ages ranging from 116.5±1.7 to 115.5±1.7 Ma for the deposit. The ages obtained by the two methods are quite close, suggesting that the rocks and ores formed approximately at the same time. The Donggou molybdenum deposit formed at least 20 Ma later than the Jinduicheng, Nannihu, Shangfanggou and Leimengou porphyry molybdenum deposits in the same molybdenum belt, implying that these deposits were formed in different tectonic settings.

关键词： SHRIMP U-Pb zircon age aluminous A-type granite-porphyry molybdenite Re-Os age Donggou molybdenum deposit East Qinling

桂西南那坡盆地河口组沉凝灰岩的时代与来源及其大地构造意义

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岩石学报 2022年第3期38卷 883-900页

作者：夏磊闫全人向忠金郑洪波牛睿云南大学地球科学学院云南省地球系统科学重点实验室昆明650500 中国科学院大学地球与行星科学学院北京100049 中国地质科学院地质研究所北京100037 河南省岩石矿物测试中心郑州450012

桂西南那坡盆地位于八布-Song Hien构造带,发育早-中三叠世岩浆岩和巨厚海相碎屑岩系,是研究华南地块南缘古特提斯造山过程的关键地区。本文对那坡盆地中三叠统河口组中-上部的两套沉凝灰岩开展了详细的岩石学、地球化学和锆石U-Pb-Hf... 详细信息

桂西南那坡盆地位于八布-Song Hien构造带,发育早-中三叠世岩浆岩和巨厚海相碎屑岩系,是研究华南地块南缘古特提斯造山过程的关键地区。本文对那坡盆地中三叠统河口组中-上部的两套沉凝灰岩开展了详细的岩石学、地球化学和锆石U-Pb-Hf同位素分析研究。两件沉凝灰岩样品LA-ICP-MS锆石U-Pb定年结果分别为240.6±1.0Ma和236.3±0.8Ma,指示河口组碎屑岩沉积时代为中三叠世拉丁期,部分为晚三叠世卡尼期早期。全岩地球化学结果显示,该沉凝灰岩属于亚碱性英安质,富集轻稀土(LREEs)和大离子亲石元素(LILEs)、Rb、Th和U,亏损高场强元素(HFSEs),具有显著的Nb、Ta和Ti负异常。沉凝灰岩锆石具有较低的ε_(Hf)(t)值(-18.6~-6.3)和较老的地壳模式年龄(t_(DM)^(C)=1664~2434Ma),结合锆石微量元素特征认为其形成于俯冲环境。整体上,那坡盆地河口组沉凝灰岩表现出俯冲作用形成的岛弧火山岩地球化学特征,推断其来源于桂西南凭祥地区的中-晚三叠世酸性火山岩。结合已有区域地质调查成果,认为华南地块南缘八布-Cao Bang古特提斯分支洋盆于晚二叠世至晚三叠世早期向北俯冲,随后自西向东呈“剪刀”式逐渐闭合。华南地块与北越地块完全碰撞拼合的时间发生在晚三叠世中晚期。

关键词：沉凝灰岩火山弧三叠纪古特提斯华南地块南缘

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中-晚二叠世上扬子地块(四川盆地区)裂解的沉积响应

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岩石学报 2021年第8期37卷 2465-2482页

作者：邓莉闫全人宋博高山林中国科学院大学地球与行星科学学院北京100049 中国地质调查局西安地质调查中心西安710054 中国石油化工股份有限公司油田勘探开发事业部北京100728

中-晚二叠世,上扬子(四川盆地区)碳酸盐岩台地内发育三条北西-南东走向的裂谷,它们是重要的油气储集区带,如普光和元坝气田就产于开江-梁平裂谷两侧。但是对这些裂谷的开始时代和构造成因等关键地质问题,还缺乏详细的沉积学研究,且存在... 详细信息

中-晚二叠世,上扬子(四川盆地区)碳酸盐岩台地内发育三条北西-南东走向的裂谷,它们是重要的油气储集区带,如普光和元坝气田就产于开江-梁平裂谷两侧。但是对这些裂谷的开始时代和构造成因等关键地质问题,还缺乏详细的沉积学研究,且存在较大争议。本文通过大比例露头剖面和钻井岩芯测量以及详细的沉积相分析对比,对开江-梁平裂谷的构造沉积过程进行了深入细致的研究。调查发现,在开江-梁平裂谷北缘,中二叠统栖霞组上段至茅口组2段发育大规模斜坡相碳酸盐岩滑塌堆积,揭上扬子地块四川盆地区于中二叠世栖霞晚期开始发生伸展裂解。茅口组3段至上二叠统长兴组为超覆于滑塌堆积之上的硅质岩和碳-硅质泥岩等深水盆地相沉积,表明开江-梁平裂谷从中二叠世茅口晚期开始由伸展裂解转变为区域沉降,即开江-梁平裂谷经历了伸展裂解和区域沉降两个构造沉积阶段。伸展裂解阶段,开江-梁平裂谷是一个发育于碳酸盐岩台地内的不对称海相半地堑盆地,北侧为发育大规模碳酸盐岩滑塌堆积的下盘断斜坡带,南侧为发育缓斜坡生物碎屑滩和礁灰岩的上盘缓斜坡带;区域沉降阶段,开江-梁平裂谷表现为东翘西降的不均匀沉降,发育自东向西不断进积的潮坪-潟湖相和高能浅滩相沉积等。本文研究成结果对分析和圈定四川盆地区中-晚二叠世油气储集相带的时空分布具有重要科学意义,也为研究碳酸盐岩滑塌堆积提供了一个新范例。

关键词：上扬子地块开江-梁平裂谷中-晚二叠世碳酸盐岩滑塌堆积伸展裂解不均匀沉降