检索结果-南通市图书馆

Acta Geologica Sinica(English Edition) 2019年第6期93卷 1783-1796页

作者： LAI Xiaodong YANG Xiaoyong School of Environmental and Chemical Engineering Foshan UniversityFoshanGuangdong 528225China CAS Key Laboratory of Crust-Mantle Materials and Environments University of Science and Technology of ChinaHefei 230026China

Detailed studies on U-Pb ages and hf isotope have been carried out in zircons from a carbonatite dyke associated with the Bayan Obo giant REE-Nb-Fe deposit,northern margin of the North China Craton(NCC),which provide insights into the plate tectonic in *** of small amounts of zircons extracted from a large sample of the Wu carbonatite dyke have yielded two ages of late Archaean and late Paleoproterozoic(with mean 207 Pb/206 Pb ages of 2521±25 Ma and 1921±14 Ma,respectively).Mineral inclusions in the zircon identified by Raman spectroscopy are all silicate minerals,and none of the zircon grains has the extremely high Th/U characteristic of carbonatite,which are consistent with crystallization of the zircon from silicate,and the zircon is suggested to be derived from trapped basement *** isotopes in the zircon from the studied carbonatite are different from grain to grain,suggesting the zircons were not all formed in one single *** ofεhf(t)values are compatible with ancient crustal sources with limited juvenile *** hf data and their TDM2 values also suggest a juvenile continental growth in Paleoproterozoic during the period of 1940–1957 *** data demonstrate the major crustal growth during the Paleoproterozoic in the northern margin of the NCC,coeval with the assembly of the supercontinent Columbia,and provide insights into the plate tectonic of the NCC in Paleoproterozoic.

关键词： crustal growth zircon U-Pb age hf isotope Bayan Obo North China Craton

Zircon U–Pb geochronology and hf isotope geochemistry of magmatic and metamorphic rocks from the Hida Belt, southwest Japan

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2021年第4期12卷 185-201页

作者： Deung-Lyong Cho Tae-Ho Lee Yutaka Takahashi Takenori Kato Keewook Yi Shinae Lee Albert Chang-sik Cheong Korea Institute of Geoscience and Mineral Resources Daejeon 34132Republic of Korea Geological Survey of Japan Tsukuba 305-8567Japan Institute for Space-Earth Environmental Research Nagoya UniversityNagoya 464-8601Japan Korea Basic Science Institute Ochang Center Cheongju 28119Republic of Korea

Zircon U–Pb and hf isotope data integrated in this study for magmatic and metamorphic rocks fromthe Hida Belt,southwest Japan,lead to a new understanding of the evolution of the Cordilleran arc system along the ancestral margins of present-day Northeast *** microprobe data for magmatic zircon domains from eight mafic tointermediate orthogneisses in the Tateyama and Tsunogawa areas yielded weighted mean 206Pb/238U ages spanning the entire Permian period(302–254 Ma).Under cathodoluminescence,primary magmatic growth zones in the zircon crystals were observed to be partially or completely replaced by inward-penetrating,irregularly curved featureless or weakly zoned secondary domains that mostly yielded U–Pb ages of 250–240 Ma and relatively high Th/U ratios(>0.2).These secondary domains are considered to have been formed by solid-state recrystallization during thermal overprints associated with intrusions of Hida *** whole-rock geochemical and Sr–Nd isotope data as well as zircon age spectra corroborate that the Hida Belt comprises the Paleozoic–Mesozoic Cordilleran arc system built upon the margin of the North China Craton,together with the YeongnamMassif in southern *** arcmagmatismalong this systemwas commenced in the Carboniferous and culminated in the Permian–Triassic transition *** positiveεhf(t)values(>+12)of late Carboniferous to early Permian detrital zircons in the Hida paragneisses indicate that there was significant input from the depleted asthenospheric mantle and/or its crustal derivatives in the early stage of arc *** the other hand,near-chondriticεhf(t)values(+5 to−2)of magmatic zircons from late Permian Hida orthogneisses suggest a lithospheric mantle *** isotopic differences between magmatic zircon cores and the secondary rims observed in some orthogneiss samples clearly indicate that the zircons were chemically open to fluids or melts during thermal *** highly positive zirconεhf(t)val

关键词： Hida Belt Zircon U–Pb age hf isotope Cordilleran arc Yeongnam Massif

Geochronology and hf isotope Study of Pegmatite in the Xiaoqinling Area of NW China: Implication for Petrogenesis and Regional Metamorphism

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2015年第3期26卷 295-305页

作者： Haixiang Zhao Shaoyong Jiang Baozhang Dai Liang Ma Jianwei Li School of Earth Sciences and Engineering Hohai University State Key Laboratory of Geological Processes and Mineral Resources Faculty of Earth ResourcesChina University of GeosciencesWuhan State Key Laboratory for Mineral Deposits Research School of Earth Sciences and EngineeringNanjing University

In this study, we carried out petrography, zircon U-Pb geochronology and hf isotopic analyses on a granitic pegmatite dyke in the Xiaoqinling area in southern margin of the North China Craton（NCC）. Our study suggests that the pegmatite dyke likely crystallized from a volatile-rich pegmatitic magma. Different from most other pegmatite elsewhere, zircon from this pegmatite dyke does not contain unusually high U and Th concentrations and suffered no evident radioactive damage, therefore we successfully obtained a zircon U-Pb dating using laser ablation-inductively coupled plasma-mass spectrometry（LA-ICP-MS）, which yields an average 207Pb/206 Pb age of 1 814±6 Ma, representing the intrusive age of the granitic pegmatite dyke. Zircon εhf（t） values are between-8.3 and-3.0, corresponding to hf depleted mantle model ages from 2 649 to 2 991 Ma with an average of 2 881 Ma. These data indicate that this granitic pegmatite dyke may have been derived from partial melting of Meso-Neoarchean metamorphic rocks from the Xiaoqinling basement. Granitic pegmatite magma may have emplaced within the Taihua Group wall rocks during the last stage of the middle to high grade metamorphism. Furthermore, according to the petrographic observation, the 1.81 Ga pegmatite dyke and the 1 800–1 750 Ma Xiong’er Group rocks were not undergone middle to high grade metamorphism, indicating 1.81 Ga as the termination of the latest regional metamorphism in the southern margin of the NCC.

关键词： Xiaoqinling pegmatite zircon U-Pb dating hf isotope metamorphism

Neoarchean(2.5-2.8 Ga) crustal growth of the North China Craton revealed by zircon hf isotope:A synthesis

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2012年第2期3卷 147-173页

作者： Andong Wang Yican Liu CAS Key Laboratory of Crust-Mantle Materials and Environments School of Earth and Space Sciences University of Science andTechnology of China Hefei 230026 China

The crustal growth of the North China Craton （NCC） during the Neoarchean time （2.5--2.8 Ga） is a hotly controversial topic, with some proposing that the main crustal growth occurred in the late Neoarch- ean （2.5--2.6 Ga）, in agreement with the time of the magmatism, whereas others suggest that the main crustal accretion took place during early Neoarchean time （2.7-2.8 Ga）, consistent with the time of crustal- formation of other cratons in the world. Zircon U-Pb ages and hf isotope compositions can provide rigorous constraints on the time of crustal growth and the evolution and tectonic division of the NCC. In this contri- bution, we make a comprehensive review of zircon hf isotope data in combination with zircon U-Pb geochro- nology and some geochemistry data from various divisions of the NCC with an aim to constrain the Neoarchean crustal growth of the NCC. The results suggest that both 2.7--2.8 Ga and 2.5-2.6 Ga crustal growth are distributed over the NCC and the former is much wider than previously suggested. The Eastern block is characterized by the main 2.7-2.8 Ga crustal growth with local new crustal-formation at 2.5-2.6 Ga, and the Yinshan block is characterized by ~2.7 Ga crustal accretion as revealed by hf-isotope data of detrital zircons from the Zhaertai Group. Detrital zircon data of the Khondalite Belt indi- cate that the main crustal growth period of the Western block is Paleoproterozoic involving some ~ 2.6 Ga and minor Early- to Middle-Archean crustal components, and the crustal accretion in the Trans-North China Orogen （TNCO） has a wide age range from 2.5 Ga to 2.9 Ga with a notable regional discrepancy. Zircon hf isotope compositions, coupled with zircon ages and other geochemical data suggest that the southern margin may not be an extension of the TNCO, and the evolution and tectonic division of the NCC is more complex than previously proposed, probably involving multi-stage crustal growth and subduction processes. However, there is no doubt that

关键词： Zircon U-Pb dating hf isotope Neoarchean crustalgrowth North China Craton

U-Pb zircon age and hf isotope compositions of Mesoproterozoic sedimentary strata on the western margin of the Yangtze massif

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2013年第8期56卷 628-639页

作者： LI HuaiKun ZHANG ChuanLin YAO ChunYan XIANG ZhenQun Tianjin Institute of Geology and Mineral Resources Nanjing Institute of Geology and Mineral Resources

The Mesoproterozoic sedimentary strata on the western margin of the Yangtze massif are a clastic-carbonate rock association intercalated with a small amount of tuff and basalt and deposited in a relatively stable environment. They are termed as the Kunyang Group, the Huili Group, and the Dongchuan Group respectively in different regions. We performed zircon U-Pb da- ting of the tuff from the groups. The results, coupled with the detrital zircon U-Pb ages of clastic rocks from the Kunyang Group and the Dongchuan Group, indicate that the sedimentation ages of the Kunyang Group and the Huili Group range from 1050 to 1000 Ma and that the Kunyang Group and the Huili Group belong to a sedimentary association with contemporaneous heterotopic facies. The detrital zircon ages and hf isotope compositions reveal that the clastic materials in the Kunyang Group and the Huili Group are derived primarily from the Cathaysia massif. Zircons of the tuff in the Dongchuan Group yields an age of ca. 1.5 Ga and all the zircon ages of clastics in the Dongchuan Group are older than 1.5 Ga, indicating that the sedimentation of the Dongchuan Group occurred during the late Mesoproterozoic Changcheng Period. Age spectra of the detrital zircons in- dicate that the clastic materials of the Dongchuan Group are derived primarily from the ancient basement of the Yangtze mas- sif. A systematic hf isotope determination of various types of zircons in the above three stratigraphic units shows that there is a rapid elevation in the initial hf value of zircon at -1.5 and 1.0 Ga. Previous studies on the sedimentary characteristics of the Kunyang Group and the Huili Group show that both were deposited in a foreland basin. Combining our data with previous studies, we suggest that the Kunyang Group and the Huili Group are foreland basin sedimentary successions formed along the southern side of the Yangtze massif after an amalgamation between the Yangtze massif and the Cathaysia massif during the Grenvillian.

关键词： western margin of the Yangtze massif Mesoproterozoic U-Pb zircon age hf isotope tectonic significance

同方期刊数据库

Geochronology of the Xingshan molybdenum deposit,Jilin Province,NE China,and its hf isotope significance

在线全文

学校读者我要写书评

暂无评论

Geochronology of the Xingshan molybdenum deposit,Jilin Provi...

Geochemistry, zircon U–Pb geochronology, and hf isotopes of S-type granite in the Baoshan block, constraints on the age and evolution of the Proto-Tethys

中国科学院地质与地球物理研究所2013年度（第13届）学术年会

作者： Ling-li Zhou Qing-dong Zeng Jian-ming Liu Henrik Friis Zuo-lun Zhang Xiao-xia Duan Key Laboratory of Mineral Resources Institute of Geology and GeophysicsChinese Academy of Sciences Department of Geoscience Aarhus University Department of Geoscience Aarhus UniversityHφegh-Guldbergs Gade 2DK-8000 Aarhus CDenmark

The Xingshan porphyry Mo deposit is located in the Lesser Xing’an Range-Zhangguangcai Range metallogenic belt,NE China,Mineralization occurred in granodioritic porphyry and monzogranite,which have zircon U-Pb ages of 171.7±2.2 Ma and 170.9±4.6 Ma,*** Re-Os dating indicates that Mo mineralization occurred at 167.3±2.5 *** geochronological data suggest that the magmatic and hydrothermal activities of the Xingshan Mo deposit happened during the Middle Jurassic in ***εvalues(6.2-11.6)and young T(473-826 Ma)of the monzogranite(XS-3)and granodioritic porphyry(XS-5)indicate that the source materials of Xingshan ore-bearing rocks are the juvenile crust,which mainly accreted on the Songnen block during the Meso-Neoproterozoic,Xingshan porphyry Mo deposits resulted from the magmatism and tectonism induced by the subduction of Paleo-Pacific Ocean.

关键词： Porphyry Mo deposit Zircon U-Pb dating Molybdenite Re-Os dating hf isotope NE China

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第1期43卷 40-58页

作者： Jianjun Zhang Chuanlong Mou Chendong Liu Yong Zhang Ting Chen Hualiang Li Institute of Geological Survey East China University of TechnologyNanchang 330013China School of Earth Sciences East China University of TechnologyNanchang 330013China Chengdu Geological Survey Center Chengdu 610081China School of Water Resources&Environmental Engineering East China University of TechnologyNanchang 330013China

Geochemistry, zircon U–Pb geochronology, and hf isotope data for the Early Paleozoic granites in the Baoshan Block reveal the Early Paleozoic tectonic evolution of the Proto-Tethys. The samples are high-K, calcalkaline, strongly peraluminous rocks with A/CNK values of 1.37–1.46, are enriched in SiO2, K2O, and Rb, and are depleted in Nb, P, Ti, Eu, and heavy rare earth elements,which indicates the crystallization fractionation of the granitic magma. Zircon U–Pb dating indicates that they formed in ca. 480 Ma. The Nansa granites have εhf(t) values ranging from-16.04 to 4.36 with corresponding TC DMages of 2.10–0.81 Ga, which suggests the magmas derived from the partial melting of ancient metasedimentary with minor involvement of mantle-derived components. A synthesis of data for the Early Paleozoic igneous rocks in the Baoshan block and adjacent(Tengchong,Qiangtang, Sibumasu, Himalaya, etc.) blocks indicates that these blocks were all aligned along the proto-Tethyan margin of East Gondwana in the Early Paleozoic. The Early Paleozoic S-type granites from Nansa were generated in a high-temperature and low-pressure(HTLP) extensional tectonic setting, which resulted from Andean-type orogeny instead of the final assembly of Gondwana or crustal extension in a non-arc environment. In certain places, an expanding environment may exist in opposition to the tectonic backdrop of the lithosphere’s thickening and shortening, leading the crust to melt and decompress,mantle-derived materials to mix, and a small quantity of peraluminous granite to emerge.

关键词： Baoshan block Early Paleozoic Granite Geochemistry Zircon Geochronology hf isotope

Magma mixing of granites at Lianghe:In-situ zircon analysis for trace elements, U-Pb ages and hf isotopes

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2011年第9期54卷 1346-1359页

作者： CONG Feng LIN ShiLiang ZOU GuangFu LI ZaiHui XIE Tao PENG ZhiMin LIANG Ting Chengdu Center of China Geological Survey Chengdu 610081 China State Key Laboratory of Geological Processes and Mineral Resources China University ofGeosciences Wuhan 430074 China

In this paper, we report an integrated study of trace element, U-Pb age and hf isotopic composition of zircons from alkali feldspar granites, granodiorites and diorite enclaves in a recently discovered ring complex at Lianghe in western Yunnan, Chi na. The granitoids showed identical U-Pb ages of 127, 115 and 122 Ma, from felsic to mafic, but had different zircon trace el ements and hf isotopic compositions. Trace element content decreased with a gradual increase in εhf(t) values of ?9.1 to ?5.4, ?4.5 to 0, and 3.6 to 6.2, respectively. Results indicate that changes in zircon trace elements generally correlate with changes in hf isotope signatures within single samples and among various granitoids. These relationships reflect the mixing of felsic and mafic magmas. Evidence indicates that depleted mantle-derived mafic magma underplating caused ancient crustal melting, and then formed large-scale granites in Lianghe during the Early Cretaceous. These granodiorites were formed mainly by the mix ing of mafic magma and granitic magma.

关键词： Lianghe zircon trace element U-Pb age hf isotope magma mixing

Ages and hf isotopes of detrital zircons from the Permian strata in the engbatu area(Inner Mongolia) and tectonic implications

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2019年第1期10卷 195-212页

作者： Bing Xu Guochun Zhao Jianhua Li Dongxing Liu Bo Wang Yigui Han Paul R. Eizenhofer Xiaoran Zhang Wenzhu Hou Qian Liu State Key Laboratory of Continental Dynamics Department of Geology Northwest University Department of Earth Sciences The University of Hong Kong Institute of Geomechanics Chinese Academy of Geological Sciences Department of Geology and Environmental Science University of Pittsburgh

The Central Asian Orogenic Belt(CAOB) was built up through protracted accretion and collision of a variety of terranes/micro-continents during Neoproterozoice Mesozoic time. To understand potential links among Paleozoic subduction and accretionary processes that were operative during the development of the southeastern CAOB, we conducted a combined U-Pb and hf-isotope analysis of detrital zircons from previously defined Devonian, Carboniferous and Early Permian strata in the Bengbatu area,Inner Mongolia. Detrital zircons from(meta-) sandstones in these strata commonly yield major Paleozoic age populations at ca. 300-261 Ma, 351-300 Ma and 517-419 Ma, and also give several Precambrian ages that range from 2687 Ma to 544 Ma. The youngest ages redefine the deposition of all these strata to be in the Middle Permian(Wordiane Capitanian) or later, much younger than previously *** ages, coupled with regional magmatic records, support an interpretation of most surrounding areas as possible detritus sources, including the Mongolian arcs to the north, the Northern Accretionary Orogen to the south, and the intervening Erenhote Hegenshan Ophiolite Belt. Zircons with magmatic ages of ca. 500-350 Ma and ca. 300-261 Ma display a large range of εhf(t) values(-13.97 to +15.31),whereas ca. 350-300 Ma zircons are dominated by positive εhf(t) values(+0.14 to +16.00). These results support the occurrence of two significant shifts of the zircon εhf(t) values, which has tectonic implications for the understanding of the Carboniferouse Permian evolution of the southeastern CAOB. A marked shift from mixed to positive zircon εhf(t) values at 350 -330 Ma likely manifests the incipient opening of the Hegenshan Ocean, due to the slab rollback of the subducting Paleo-Asian Oceanic lithosphere. Another shift from positive to mixed zircon εhf(t) values at ca. 300 Ma likely corresponds to a tectonic switch from syn-orogenic subduction-related to post-orogenic extensional setting, genet

关键词： Detrital zircon U-Pb dating hf isotope Central Asian Orogenic Belt Subduction Back-arc basin

Geochronology, geochemistry and hf isotopes of andesites in the Sandaowanzi gold deposit(Great Xing’an Range, NE China): implications for petrogenesis, tectonic setting,and mineralization

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2021年第2期40卷 251-270页

作者： Runtao Yu Bile Li Fengyue Sun Zhihua Li Huawei Li Yufan Shi College of Earth Science Jilin UniversityNo.2199 Jianshe StreetChangchun 130061China

The Sandaowanzi gold deposit is an extremely Au-rich deposit in the Northern Great Hinggan Range in recent *** U-Pb geochronology,hf isotope analysis,and the geochemistry of andesites of the Longjiang Formation from the Sandaowanzi gold deposit were used to investigate the origin,magmatic evolution as well as mineralization and tectonic setting of the Early Cretaceous epithermal gold deposits in the northern Great Hinggan Range *** U-Pb dating reveals an emplacement age of 123.4±0.3 Ma,indicating that the andesites of the Sandaowanzi gold deposit was formed during the Early *** andesites are enriched in light rare earth elements relative to heavy rare earth elements and have weak negative Eu anomalies(δEu=0.76-0.90).The rocks are also enriched in large-ion lithophile elements,such as Rb,Ba,Th,U,and K,and depleted in the high-field-strength elements,such as Nb,Ta,and *** characteristics are typical of volcanic rocks related to *** zircons from the andesite samples have relatively homogeneous hf isotope ratios,176hf/177hf values of 0.282343-0.282502,εhf(t)values of-12.58 to-6.95,and two-stage model ages(TDM2)of 1743-1431 *** characteristics of the andesites of the Longjiang Formation are consistent with derivation from partial melting of enriched mantle wedge metasomatized by subducted-slab-derived *** rocks formed in an extensional environment associated with the closure of the Mongol-Okhotsk Ocean and subduction of the Paleo-Pacific *** occurred towards the end of volcanism,and the magmatic activity and mineralization are products of the same geodynamic setting.

关键词： Andesites of longjiang formation Zircon U–Pb geochronology hf isotope Geochemistry Sandaowanzi gold deposit