检索结果-南通市图书馆

Ophiolite-Hosted Diamond: A New Window for Probing Carbon Cycling in the Deep Mantle

在线全文

学校读者我要写书评

暂无评论

Engineering 2019年第3期5卷 406-420页

作者： Dongyang Lian jingsui yang School of Earth Sciences and Engineering Nanjing University Nanjing 210023 China CARMA Key Laboratory of Deep-Earth Dynamics of MLR Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China

As reported in our prior work, we have recovered microdiamonds and other unusual minerals, including pseudomorph stishovite, moissanite, qingsongite, native elements, metallic alloys, and some crustal minerals (i.e., zircon, quartz, amphibole, and rutile) from ophiolitic peridotites and chromitites. These ophiolite-hosted microdiamonds display different features than kimberlitic, metamorphic, and meteoritic diamonds in terms of isotopic values and mineral inclusions. The characteristic of their light carbon isotopic composition implies that the material source of ophiolite-hosted diamonds is surface-derived organic matter. Coesite inclusions coexisting with kyanite rimming an FeTi alloy from the Luobusa ophiolite show a polycrystalline nature and a prismatic habit, indicating their origin as a replacement of stishovite. The occurrence in kyanite and coesite with inclusions of qingsongite, a cubic boron nitride mineral, and a high-pressure polymorph of rutile (TiO2 II) point to formation pressures of 10–15 GPa at temperatures^1300℃, consistent with depths greater than 380 km, near the mantle transition zone (MTZ). Minerals such as moissanite, native elements, and metallic alloys in chromite grains indicate a highly reduced environment for ophiolitic peridotites and chromitites. Widespread occurrence of diamonds in ophiolitic peridotites and chromitites suggests that the oceanic mantle may be a more significant carbon reservoir than previously thought. These ophiolite-hosted diamonds have proved that surface carbon can be subducted into the deep mantle, and have provided us with a new window for probing deep carbon cycling.

关键词： Ophiolite-hosted diamond Coesite Stishovite Podiform chromitites Mantle transition zone

Mineral inclusions in zircon domains and geological significance of SHRIMP U-Pb dating for coesite-bearing zircons of paragneiss in Sulu terrane, eastern China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2005年第2期48卷 175-184页

作者： LIU Fulai yang jingsui XU Zhiqin Institute of Geology Chinese Academy of Geological SciencesBeijing100037China Institute of GeologyChinese Academy of Geological SciencesBeijing100037China Institute of GeologyChinese Academy of Geological SciencesBeijing100037China

Laser Raman spectroscopy and cathodoluminescence (CL) image reveal that zircons separated from paragneisses in the southwestern Sulu terrane (eastern China) preserve multi-stage mineral assemblages in different zircon domains. In the same paragneiss zircon sample, some zircon grains retain inherited (detrital) cores with abundant low-pressure mineral inclusions of Qtz + Phe + Ap + impurities and Qtz + Phe + impurities. The ultrahigh-pressure (UHP) metamorphic overgrowths mantles of these zircons preserve Coe, Coe + Phe and other UHP mineral inclusions, indicating that these inherited (detrital) zircons from protoliths experienced metamorphic recrystallization during the Sulu UHP metamorphic event. However, other zircon grains preserve UHP mineral inclusions of Coe, Coe + Ap and Coe + Phe in the cores and mantles, whereas the outmost rims contain quartz (Qtz) and other low-pressure mineral inclusions. These phenomena prove that the second group zircons were crystallized at UHP metamorphic stage and overprinted by the late retrogressive metamorphism related to the Sulu terrane exhumation. SHRIMP U-Pb dating reveals that zircons separated from the paragneisses recorded complicated geochronological traces. Some zircons retain inherited cores with the 206Pb/238U ages of 284-754 Ma, indicating the complexity of the detrital zircons in protoliths. Coesite-bearing zircon domains recorded 238-266 Ma (with the average age of 245(14 Ma) for the UHP metamorphic event. The retrogressive rims of zircons recorded 213-223 Ma (with the average age of 217(15 Ma) for the late-stage amphibolite facies metamorphic event, indicating that the rapid exhumation time for the Sulu UHP terrane is about 220 Ma.

关键词： Sulu terrane, paragneiss, zircon, mineral inclusion, cathodoluminescence, SHRIMP U-Pb dating.

Eclogitic metapelites in the western segment of the north Qaidam Mountains:Evidence on"in situ"relationship between eclogite and its country rock

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2004年第12期47卷 1102-1112页

作者： ZHANG Jianxin MENG Fancong yang jingsui Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China

In Yuka-Luofengpo area of the north Qaidam Mountains, eclogitic metapelites are recognized. The metapelites enclosed lenses of eclogites, and locally intercalated with eclogites. Their typical mineral assemblages are garnet+kyanite+chloritoid+phengite+quartz+rutile. Strong growth zoning is preserved in garnets of metapelites, and phengite contains up to 3.4 Si per formula units. The petrographic observations and textural relations testify to the following sequence of mineral assemblages connected to three metamorphic stage: (1) Grt+ChlI+CldI +PheI ± StI+Qtz; (2) Grt+Ky+PheII±CldII+Qtz; and (3) Grt+CldIII+ChlII+PheIII+StII ± ky+ Qtz. Applying THERMOCALC Program, Grt-Phe thermometer and Grt-Ky-Phe-Qtz barometry, P-T conditions for three metamorphic stages were obtained: P=1.07±0.31GPa, T=564±22? (prograde stage); P=2.3–3.1GPa, T=615–700°C-(peak stage); and P =1.22 ± 0.26GPa, T=581±20°C (retrograde stage). A hairpin shape P-T path similar to that of adjacent eclogite is inferred. In combination with eclogitic mineral relics in marbles and orthogneisses enclosing eclogites, we thought that the relationship between eclogites and country rocks is “in situ” rather than “tectonic emplacement”.

关键词： eclogitic metapelites, in situ, tectonic emplacement.

Probing the Troodos Ophiolite:IGCP-649 Workshop and Field Excursion Held in Agros-Cyprus

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2016年第3期90卷 1041-1044页

作者： yang jingsui Julian PEARCE Yildirim DILEK CARMA Instittute of GeologyCAGSBeijingChina Cardiff University UK Miami University USA

The second IGCP-649 Workshop, held in Agros-Cyprus during 14-20 May 2016, brought together nearly fifty international scientists from around the world, and included a 5-day field excursion on the classic Troodos ophiolite. Organized by the IGCP-649 Project Leadership and the Geological Survey Department of Cyprus, the workshop provided a forum for discussions on the latest views and interpretations on the petrogenesis of crustal and upper mantle peridotites in ophiolites, and introduced many young researchers and students to the intemal structure of the classical Troodos ophiolite. This was particularly the case for a large group of Chinese scholars and students, who visited Cyprus and the Troodos ophiolite for the first time. A 4-day profile across the complete ophiolite sequence gave these scientists a first- hand opportunity to examine the lithological and compositional variations within the Cretaceous oceanic crust and to study the igneous and tectonic contacts between them. Lively discussions by the experts and students in front of some of the best 3-dimensional outcrops were most fruitful and allowed all participants to compare the Troodos tectonics with some of ophiolites elsewhere. structure, geochemistry and the other well-documented

关键词： Probing the Troodos Ophiolite IGCP-649 Workshop and Field Excursion Held in Agros-Cyprus

Indosinian Orogenesis in the Lhasa Terrane, Tibet: New Muscovite ^(40)Ar-^(39)Ar Geochronology and Evolutionary Process

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2012年第5期86卷 1116-1127页

作者： LI Huaqi XU Zhiqin yang jingsui TANG Zhemin Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China

Muscovite 40 Ar-39 Ar dating of muscovite-quartz schist, eclogite and retrograde eclogite indicates an Indosinian orogenesis occurred at 220-240 Ma in the Lhasa terrane, which is caused by the closure of Paleo-Tethyan ocean basin and the following collision of the northern Lhasa terrane and southern Gondwana land. This Indosinian orogenesis is further confirmed by the regional sedimentary characteristics, magmatic activity and ophiolite mélange. This evidence suggests that the Indosinian orogenic belt in the Lhasa terrane is widely distributed from the Coqen county in the west, and then extends eastward through the Ningzhong and Sumdo area, finally turning around the eastern Himalayan syntaxis into the Bomi county. Based on the evolutionary process, the geological development of Lhasa terrane from early Paleozoic to early Mesozoic can be divided into seven stages. All of the seven stages make up a whole Wilson circle and reveal a perfect evolutionary process of the Paleo-Tethys ocean between the northern Lhasa terrane and southern Gondwana land. The Indosinian orogenisis is a significant event for the evolution of the Lhasa terrane as well as the Tibetan Plateau.

关键词： 40 Ar-39 Ar geochronology Lhasa terrane Indosinian orogenesis Tibet

Helium Isotopic Composition of the Songduo Eclogites in the Lhasa Terrane,Tibet: Information from the Deep Mantle

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2019年第3期30卷 563-570页

作者： Zhaoli Li jingsui yang Tianfu Li Songyong Chen Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources Institute of GeologyChinese Academy of Geological Sciences

Helium isotopic compositions are considered to be ideal tracers to identify whether mantle materials have been added to crustal rocks or *** this paper,we present the helium isotopic compositions of the Songduo eclogites in the Lhasa terrane,*** found that garnet and omphacite in the eclogites have different helium retention *** 4He content of most omphacite grains are about 10–20 times of that of garnet,suggesting that omphacite has a higher ability to capture 4He than ***,there is about 10–20 times difference in 3He content between omphacite and garnet in the same eclogite *** 3He/4He ratios of garnet and omphacite in these rocks range from 0.27 to 0.60 Ra(relative to the modern air 3He/4He ratio,1.4×10^-6).These ratios are within the range of both mantle-and crust-derived helium,suggesting mixed *** Songduo eclogites have much higher3He/4He ratios than those observed in the Dabie eclogites of eastern *** high ratios are typically thought to be associated with deep mantle *** cautiously conclude that deep mantle materials might have been involved during the formation of the Songduo eclogites.

关键词： eclogite helium isotopic composition HP/UHP metamorphic belt Lhasa terrane Qinghai-Tibet Plateau

Petrology and Geochemistry of the Dangqiong Ophiolite,Western Yarlung-Zangbo Suture Zone,Tibet,China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2019年第2期93卷 344-361页

作者： XU Xiangzhen yang jingsui XIONG Fahui GUO Guolin CARMA(Center for Advanced Research on Mantle) Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources Institute of Geology Chinese Academy of Geological Sciences State Key Laboratory Breeding Base of Nuclear Resources and Environment East China Institute of Technology

The Dangqiong ophiolite, the largest in the western segment of the Yarlung-Zangbo Suture Zone(YZSZ)ophiolite belt in southern Tibet, consists of discontinuous mantle peridotite and intrusive mafic rocks. The former is composed dominantly of harzburgite, with minor dunite, locally lherzolite and some dunite containing lenses and veins of chromitite. The latter, mafic dykes(gabbro and diabase dykes), occur mainly in the southern part. This study carried out geochemical analysis on both rocks. The results show that the mantle peridotite has Fo values in olivine from 89.92 to 91.63 and is characterized by low aluminum contents(1.5–4.66 wt%) and high Mg# values(91.06–94.53) of clinopyroxene. Most spinels in the Dangqiong peridotites have typical Mg# values ranging from 61.07 to 72.52, with corresponding Cr# values ranging from 17.67 to 31.66, and have TiO2 contents from 0 to 0.09%, indicating only a low degree of partial melting(10–15%). The olivine-spinel equilibrium and spinel chemistry of the Dangqiong peridotites suggest that they originated deeper mantle(>20 kbar). The gabbro dykes show N-MORB-type patterns of REE and trace elements. The presence of amphibole in the Dangqiong gabbro suggests the late-stage alteration of subduction-derived fluids. All the lherzolites and harzburgites in Dangqiong have similar distribution patterns of REE and trace elements, the mineral chemistry in the harzburgites and lherzolites indicates compositions similar to those of abyssal and forearc peridotites, suggesting that the ophiolite in Dangqiong formed in a MOR environment and then was modified by late-stage melts and fluids in a suprasubduction zone(SSZ) setting. This formation process is consistent with that of the Luobusa ophiolite in the eastern Yarlung-Zangbo Suture Zone and Purang ophiolite in the western Yarlung-Zangbo Suture Zone.

关键词： gabbro mantle peridotite Dangqiong ophiolite Yarlung-Zangbo Suture Zone Tibet

Accretion Processes of Oceanic Crust in Slow-spreading Ridges:Plagiogranite Perspective of the Xigaze Ophiolite,South Tibet

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2022年第6期96卷 1945-1959页

作者： LI Yuan LI Ruibao yang Shengbiao ZHANG Jian yang jingsui Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China School of Earth Sciences and Resources Chang’an UniversityXi’an 710054China Tianjin Institute of Geology and Mineral Resources Tianjing 300170China School of Earth Sciences and Engineering Nanjing UniversityNanjing 210023China

Structural and petrological data suggest that the Xigaze ophiolite from the Yarlung Zangbo Suture Zone(YZSZ)in south Tibet was a typical slow-spreading ridge.A new field,geochemical,mineral,and U-Pb zircon dataset of plagiogranite intrusions were used to constrain the dynamic processes of oceanic accretion in this slow-spreading *** mainly occur as dykes or intrusions intruded into the whole sequence of the ophiolite and have a similar orientation to the dolerite dykes developed in the late stage of detachment faulting.U-Pb zircon ages of 122–123 Ma were obtained for two types of plagiogranites and associated dolerite *** geochemical and mineralogical examinations suggest that the plagiogranites are the product of low-pressure(2–3 kbar)fractional crystallization of midocean ridge basalt-like magma and unlikely to have been derived from the partial melting of hydrous gabbroic *** complex cross-cut relationship between the plagiogranites and ophiolite sequence reflects that they are controlled by small discontinued melt lenses rather than a big magma chamber under the ridge axis and reveals multiple injections during the oceanic crust *** formation of plagiogranites possibly reflects the complex characteristic of oceanic accretion at slow-spreading ridges,time-dependent on structural(external)and magmatic(internal)processes.

关键词： Xigaze ophiolite plagiogranite fractional crystallization multiple magma injection ocean-continent transition zone

Five Years of IGCP 649 Project-Diamonds and Recycled Mantle

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2020年第S01期94卷 1-3页

作者： yang jingsui SHEN Tingting ZHANG Cong QIU Tian Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China School of Earth Sciences and Engineering Nanjing UniversityNanjing 210023China

The IGCP-649 project―Diamonds and Recycled Mantle‖is an International Geosciences Program sponsored by UNESCO and IUGS in March *** is a global research project,aimed to carry out extensive and systematic research on peridotites,chromitites and related materials such as diamond,moissanite and other unusual minerals,from different ophiolites in global orogenic belts,for understanding the formation and origin of deepmantle minerals in oceanic lithosphere,the origin of carbon for the ophiolite-hosted diamonds,the evolution of Earth’s mantle and the dynamic process of ophiolite *** IGCP-649 project(2015–2019)is undertaken by the Center for Advanced Research on the Mantle(CARMA),leading by *** yang,Institute of Geology,Chinese Academy of Geological Sciences,and cooperated by an international team of researchers including *** Dilek of Miami University(USA),*** L Griffin of Macquarie University(Australia),*** *** of Dalhousie University(Canada),*** Milushi of Polytechnic University of Tirana(Albania),and *** Metwaly Abu Anbar of Tanta University(Egypt).

关键词： IGCP mantle minerals