检索结果-南通市图书馆

Genesis of pyroxenite Veins in the Zedang Ophiolite,Southern Tibetan Plateau

Acta Geologica Sinica(English Edition) 2023年第3期97卷 707-726页

作者： XU Xiangzhen XIONG Fahui Basem ZOHEIR YAN Jinyu ZHANG Boyang GAO Jian YANG Jingsui Center for Advanced Research on the Mantle(CARMA) Key Laboratory of Deep-Earth Dynamics of Ministry of Land and ResourcesInstitute of GeologyChinese Academy of Geological SciencesBeijing 100037China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Department of Geology Faculty of ScienceBenha UniversityBenha 13518Egypt Institute of Geosciences University of KielKiel 24118Germany

Understanding the nature of parental melts for pyroxenite veins in supra-subduction zone(SSZ)ophiolites provides vibrant constraints on melt infiltration processes operating in subduction *** Zedang ophiolitic massif in the eastern Yarlung–Zangbo suture zone in Tibet consists of mantle peridotites and a crustal section of gabbro,diabase,and *** of two pyroxenite varieties cut the southern part of the Zedang *** pyroxenite rocks have different geochemical characteristics,where the first variety(type-I)has relatively higher contents of SiO_(2)(51.82–53.08 wt%),MgO(20.08–23.23 wt%),andΣPGE(3.42–13.97 ppb),and lower Al_(2)O_(3)(1.59–2.28 wt%)andΣREE(1.63–2.94 ppm).The second pyroxenite variety(type-II)is characterized by SiO_(2)(45.44–49.61 wt%),Mg O(16.68–19.78 wt%),Al_(2)O_(3)(4.24–8.77 wt%),ΣPGE(14.46–322.06 ppb),andΣREE(5.82–7.44 ppm).pyroxenite type-I shows N-MORB-like chondritenormalized REE *** U-Pb ages of pyroxenite type-I(194±10 Ma),associated ophiolitic gabbro(135.3±2.0 Ma),and plagiogranite(124.2±2.3 Ma)evidently imply episodic evolution of the Zedang *** mineralogical and geochemical characteristics of the investigated pyroxenites can be explained by subduction-initiated hydrous melting of metasomatized sub-arc mantle,later overprinted by sub-slab mantle melting triggered by upwelling asthenosphere during the Jurassic–Early Cretaceous *** geochemical variations in pyroxenite vein composition,coupled with age differences amongst the other ophiolite units,may correspond to intermittent emplacement of pyroxenite dikes and isotropic gabbroic intrusions where the geodynamic setting progressed from arc maturation and slab rollback to slab tearing and delamination.

关键词： pyroxenite mineralogy geochemistry forming processes Zedang ophiolite Yarlung–Zangbo suture zone

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The mineral chemistry of pyroxenite xenoliths in the volcanic rocks of Hoh Xil and their significance

引用

Science China Earth Sciences 2001年第S1期44卷 128-138页

作者：吴才来杨经绥许志琴李海兵史仁灯 1. Institute of Geology Chinese Academy of Geological Sciences 100037 Beijing China

The pyroxenite xenoliths in the volcanic rocks of Hoh Xil consist of clinopyroxenes and orthopyroxenes. The mineral composition of these pyroxenes is similar to that of mantle xenoliths including peridotite and pyroxenite from China and abroad, and different from that of granulites. The pyroxenes formed at 1101-1400 ℃ (averaging 1250 ℃) and under 30-60 kb (averaging 46 kb). We deduced that the magma was derived from the mantle at a depth of more than 150 km, which fits in with the geophysical conclusion that the low-velocity layer existed in the mantle under 150km.

关键词： : pyroxenite xenoliths mineral chemistry Hoh Xil.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A petrogenetic study of the garnet pyroxenite enclaves in spinel peridotite, North Dabieshan, China

引用

Science China Earth Sciences 2000年第S1期43卷 189-199页

作者：游振东钟增球索书田郑曙 China University of Geosciences Wuhan 430074 China

Recently, garnet pyroxenite enclaves within peridotites occurring near Raobazhai, Huoshan County, have been discovered. The garnet pyroxenite is small pods, decimeters in size, enclosed within intensively serpentinized peridotites. Major mineral components comprise: garnet (Prpas-as), sodium augite (Jd 10-25) with a small amount of ilmenite. There are two stages of retro-metamorphism: the retrogressive granulite facies mineral assemblage is superimposed by that of amphibolite facies. The host rocks of the garnet pyroxenite are spinel peridotites, including spinel harzburgite and Iherzolite. Due to intensive serpentinitization, only 5%-40% of the relic olivine (Fo92-93) are preserved. The orthopyroxenes are Mg-rich (En87-93) with bending of cleavages and granulation at their margins showing intracrystalline plasticity. On the basis of garnet-clinopyroxene Fe-Mg exchange equilibrium geothermometry proposed by Ellis & Green (1979) and Krogh (1988) KD= 4.06 - 5.28; T= 793-919℃, P= 1.5 GPa are estimated for the garnet pyroxenite. It is inferred that the peridotites are mantle rocks about 60 km in depth. During the exhumation of the orogenic belt, it was tectonically emplaced into the lower crust in the solid state and then uplifted to the shallow depth. Obviously, this kind of garnet pyroxenite must be petrogenetically related to its host rock. The REE distribution pattern and the Ni-Co-Sc diagram reveal that they are chemically equivalent to the basaltic melt and ultramafic residua respectively derived from partial melting of mantle rocks.

关键词： garnet pyroxenite spinel peridotite petrogenesis geochemistry Dabieshan.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Petrogenesis of the Maowu pyroxenite-eclogite body from the UHP metamorphic terrane of Dabieshan:chemical and isotopic constraints

Petrogenesis of the Maowu pyroxenite-eclogite body from the ...

引用

中国科学院地质与地球物理研究所2003学术年会

作者： Bor-ming Jahn O.Henin Geosciences Rennes Universite de Rennes 1.CNRS-UPR 466135042 RennesFrance Geosciences Rennes Universite de Rennes 1CNRS-UPR 466135042 RennesFrance

The Maowu eclogite-pyroxenite body is a small(250×50 m) layered intrusion that occurs in the ultra-high-pressure(UHP) metamorphic terrane of Dabieshan,*** the adjacent Bixiling complex,the Maowu intrusion was initially emplaced at a crustal level,then subducted along with the country gneisses to mantle depths and underwent UHP metamorphism during the collision of the North and South China Blocks in the *** paper presents the results of a geochemical and isotopic investigation on the metamorphosed Maowu *** Maowu intrusion has undergone open system chemical and isotopic behavior three *** crustal contamination during magmatic differentiation is manifested by high initial Sr/Sr ratios (0.707-0.708) and inhomogeneous negativeε(T) values of -3 to - 10 at 500 Ma(probable protolith age).Post-magmatic and pre-UHP metamorphic metasomatism is indicated by sinusoidal REE patterns of garnet orthopyroxenites,lack of whole-rock (WR) Sm-Nd isochronal relationship,lowδO values and an extreme enrichment of Th and REE in a clinopyroxenite. Finally,K and Rb depletion during UHP metamorphism is deduced from the high initial Sr/Sr ratios unsupported by in situ Rb/Sr *** ICP-MS spot analyses on mineral grains show that(1) Grt and Cpx attained chemical equilibrium during UHP metamorphism,(2) Cpx/Grt partition coefficients for REE correlate with Ca,and(3) LREE abundances in whole rocks are not balanced by that of the principal phases(Grt and Cpx),implying that the presence of LREE-rich accessory phases,such as monazite and apatite,is required to account for the REE budget. Sm-Nd isotope analyses of minerals yielded three internal isochrons with ages of 221±5 Ma andε(T)= -5.4 for an eclogite,231±16 Ma andε(T)= - 6.2 for a garnet websterite,and 236±19 Ma andε(T) = - 6.9 for a garnet clinopyroxenite. The Cpx/Grt chemical equilibrium and the consistent mineral isochron ages indicate that the metasomatic processes mentioned above must have occurred prior

关键词： Dabieshan Maowu UHP metamorphism Eclogite pyroxenite Sm-Nd isotopes Age

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

Post-collisional Ultrapotassic Mafic Magmatism in South Tibet: Products of Partial Melting of pyroxenite in the Mantle Wedge Induced by Roll-back and Delamination of the Subducted Indian Continental Lithosphere Slab

Post-collisional Ultrapotassic Mafic Magmatism in South Tibe...

引用

中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： Zhengfu Guo Marjorie Wilson Maoliang Zhang Zhihui Cheng Lihong Zhang Key Laboratory of Cenozoic Geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences School of Earth and Environment University of Leeds

Post-collisional(25-8 Ma) ultrapotassic mafic magmatic rocks occur to the north of the India-Asia collision zone within the Lhasa terrane of the southern Tibetan Plateau,forming a near 1000 km long semi-continuous igneous *** include both extrusive and intrusive facies,although lava flows *** understand their petrogenesis,the mineral chemistry of olivine phenocrysts and xenocrysts and whole-rock major and trace element and Sr-Nd-Pb isotope data are presented for the most primitive mafic magmatic rocks(MgO>6wt%) from west to *** studied samples are characterized by high MgO(6.28-15.75 wt%),KO(4-76-8-89 wt%),SiO(46-44-59-74 wt%),Ba(1368-14076ppm),Th(69-336ppm) and Ni(106-527 ppm) ***-normalized rare earth element(REE) patterns show enrichment in light rare earth elements(LREE),flat heavy REE(HREE) patterns and negative Eu *** REE patterns have a very distinctive inverted ’spoon shape’,which appears to be a common characteristic of collision-related ultrapotassic *** mantle-normalized incompatible trace element patterns exhibit strong enrichments in large ion lithophile elements(LILE) relative to high field strength elements(HFSE)and strong negative Ta-Nb-Ti anomalies,which are typical of subduction-related *** ultrapotassic magmatic rocks studied have extremely radiogenic initial Sr isotopic compositions(0-712379-0-737616) and low(Nd/Nd)(0.511662-0.511984).Combined with their Pb isotope compositions[(Pb/Pb) = 18.30-18.92;(Pb/Pb) = 15.65-15.87;(Pb/Pb) = 39.02-39.76]these data are consistent with the involvement of a subducted continental crustal component in their *** Sr-Nd-Pb isotope compositions exhibit linear trends between depleted mid-ocean ridge basalt(MORB)-source mantle(DMM) and Indian continental *** extreme enrichment of the upper mantle below south Tibet is considered to result from the addition of components derived from subducted Indian continental crust to the overlying m

关键词： post-collisional ultrapotassic magmatism Indian continental subduction pyroxenite slab roll-back Lhasa terrane south Tibet

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

Melt migration and melt-rock reaction in the Alpine-Apennine peridotites:Insights on mantle dynamics in extending lithosphere

引用

Geoscience Frontiers 2020年第1期11卷 151-166页

作者： Elisabetta Rampone Giulio Borghini Valentin Basch DISTAV University of GenovaCorso Europa 26I-16132 GenovaItaly Dipartimento di Scienze della Terra University of Milanovia Botticelli 2320133 MilanoItaly

The compositional variability of the lithospheric mantle at extensional settings is largely caused by the reactive percolation of uprising melts in the thermal boundary layer and in lithospheric *** Alpine-Apennine(A-A)ophiolites are predominantly constituted by mantle peridotites and are widely thought to represent analogs of the oceanic lithosphere formed at ocean/continent transition and slow-to ultraslow-spreading *** and geochemical studies on the A-A mantle peridotites have revealed that they preserve significant compositional and isotopic heterogeneity at variable scale,reflecting a long-lived multi-stage melt migration,intrusion and melt-rock interaction history,occurred at different lithospheric depths during progressive *** A-A mantle peridotites thus constitute a unique window on mantle dynamics and lithosphere-asthenosphere interactions in very slow spreading *** this work,we review field,microstructural and chemical-isotopic evidence on the major stages of melt percolation and melt-rock interaction recorded by the A-A peridotites and discuss their consequences in creating chemical-isotopic heterogeneities at variable scales and enhancing weakening and deformation of the extending *** will be on three most important stages:(i)old(pre-Jurassic)pyroxenite emplacement,and the significant isotopic modification induced in the host mantle by pyroxenite-derived melts,(ii)melt-peridotite interactions during Jurassic mantle exhumation,*** open-system reactive porous flow at spinel facies depths causing bulk depletion(origin of reactive harzburgites and dunites),and the shallower melt impregnation which originated plagioclase-rich peridotites and an overall mantle *** infer that migrating melts largely originated as shallow,variably depleted,melt fractions,and acquired Si-rich composition by reactive dissolution of mantle pyroxenes during upward *** melt-rock reaction processes

关键词： Mantle peridotite pyroxenite Melt migration Melt impregnation Melt-rock reaction Alpine-Apennine ophiolites

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Continental crust formation at arcs, the arclogite ‘‘delamination''cycle, and one origin for fertile melting anomalies in the mantle

引用

Science Bulletin 2015年第13期60卷 1141-1156页

作者： Cin-Ty A.Lee Don L.Anderson Department of Earth Science MS-126 Rice University Department of Geological and Planetary Sciences California Institute of Technology

The total magmatic output in modern arcs,where continental crust is now being formed, is believed to derive from melting of the mantle wedge and is largely basaltic. Globally averaged continental crust, however, has an andesitic bulk composition and is hence too silicic to have been derived directly from the mantle. It is well known that one way this imbalance can be reconciled is if the parental basalt differentiates into a mafic garnet pyroxenitic residue/cumulate(‘‘arclogite'') and a complementary silicic melt, the former foundering or delaminating into the mantle due to its high densities and the latter remaining as the *** the Sierra Nevada batholith in California as a case study, the composition of mature continental arc crust is shown in part to be the product of a cyclic process beginning with the growth of an arclogite layer followed by delamination of this layer and post-delamination basaltic underplating/recharge into what remains of the continental crust.A model is presented, wherein continuous arc magmatism and production of arclogites in continental arcs are periodically punctuated by a delamination event and an associated magmatic pulse every *10–30 My. The recycling flux of arclogites is estimated to be *5 %–20 % that of oceanic crust recycling by subduction. Delaminated arclogites have the necessary trace-element compositions to yield time-integrated isotopic compositions similar to those inferred toexist as reservoirs in the mantle. Because of their low melting temperatures, such pyroxenites may be preferentially melted, possibly forming a component of some hotspot magmas.

关键词： pyroxenite Eclogite Delamination Cumulate Continental crust

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Oceanic Island Basalts from the Darbut and Karamay Ophiolitic Mélange in West Junggar(NW China): Product of a Middle Devonian Mantle Plume?

引用

Acta Geologica Sinica(English Edition) 2015年第A2期89卷 105-106页

作者： YANG Gaoxue LI Yongjun TONG Lili YANG Baokai School of Earth Science & Resources Chang’an University

The Central Asian Orogenic Belt （CAOB） is an immense accretionary orogen and is an important site of Phanerozoic crustal growth （Fig. la; Sengor et al., 1993; Jahn, 2004; Windley et al., 2007; Xiao et al., 2008;Saf... 详细信息

关键词： RESEARCH Igneous rocks pyroxenite Chromite Orogenic belts Basalt Ophiolites

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

西伯利亚克拉通南缘奥里洪地块麻粒相变质作用及构造意义

引用

岩石学报 2009年第12期25卷 3346-3356页

作者：李晓春于津海桑丽芹罗莉朱国荣 Nanjing Univ Dept Earth Sci State Key Lab Mineral Deposits Res Nanjing 210093 Peoples R China

早古生代西伯利亚克拉通南缘发生了大规模的增生-碰撞造山运动,本文研究的地区——奥里洪地块记录了巴尔古津微板块与西伯利亚克拉通碰撞造山的事件。对奥里洪地块出露的两种典型的高级变质岩——石榴辉石岩和石榴黑云片麻岩的矿物成分... 详细信息

早古生代西伯利亚克拉通南缘发生了大规模的增生-碰撞造山运动,本文研究的地区——奥里洪地块记录了巴尔古津微板块与西伯利亚克拉通碰撞造山的事件。对奥里洪地块出露的两种典型的高级变质岩——石榴辉石岩和石榴黑云片麻岩的矿物成分分析和变质温压计算,表明它们都经历了麻粒岩相的峰期变质作用,峰期变质温度达到770～800℃,而压力曾达到1.0GPa左右;峰后的退变质作用仍具有较高的温度,但压力明显降低(700～730℃,0.65GPa和710～766℃,0.50GPa),显示了一个近等温降压(ITD)的顺时针P-T轨迹特征。石榴黑云片麻岩中变质锆石的原位LA-ICP-MS U-Pb定年表明,麻粒岩相峰期变质年龄为479±2Ma,而峰前变质可能在500Ma就已经开始。峰后的退变质作用很可能发生在475～460Ma之后。整个造山作用持续了至少35Ma。对比蒙古-图瓦地块及中国东北佳木斯-额尔古纳地块已厘定出的变质作用及岩浆活动年龄可以发现,西伯利亚克拉通南缘不同地区增生-碰撞造山作用发生的时间是不同的,奥里洪地区造山作用相对年轻。

关键词：西伯利亚克拉通额尔古纳地块退变质作用构造意义 tectonic significance retrograde metamorphism granulite facies metamorphism 碰撞造山作用峰期变质 southern Mineral composition metamorphic rocks garnet pyroxenite collision orogeny 麻粒岩相 high temperature 石榴辉石岩片麻岩矿物成分分析地区

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Discovery and Tectonic Significance of the Early Paleozoic Nuodong Ophiolite in the North-western Yunkai Massif, South China

引用

Acta Geologica Sinica(English Edition) 2015年第A2期89卷 58-59页

作者： LIU Songfeng PENG Songbai WU Changfeng LIN Musen School of Geosciences China University of Geosciences Wuhan 430074 China Center for Global Tectonics China University of Geosciences Wuhan 430074 China Western Fujian Geological Team Xiamen 361003 China College of Zijin Minning Fuzhou University Fuzhou 350108 China

In this study we report the Early Paleozoic strongly deformed metabasalt, metadiabase and metapyroxenolite, located in the North-Western YunKai massif, South China,

关键词： PLATE tectonics RESEARCH OPHIOLITES PALEOZOIC Era pyroxenite IGNEOUS rocks

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：