共查询到20条相似文献，搜索用时 863 毫秒
1.
《Scientia Geologica Sinica》1997,(3)
ＳＯＭＥＮＥＷＯＰＩＮＩＯＮＳＡＢＯＵＴＴＲＩＡＳＳＩＣＧＡＳＴＲＯＰＯＤＡＳＳＥＭＢＬＡＧＥＳＩＮＣＨＩＮＡＰａｎＹｕｎｔａｎｇ（ＧｒａｄｕａｔｅＳｃｈｏｌ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅｉｊｉｎｇ１０００３９）（Ｒｅｃｅ... 相似文献
2.
《Scientia Geologica Sinica》1997,(3)
ＨＹＡＬＯＰＨＡＮＥＢＥＡＲＩＮＧＧＮＥＩＳＳＩＮＮＯＲＴＨＣＨＩＮＡＣＲＡＴＯＮＡＮＤＩＴＳＧＥＯＬＯＧＩＣＡＬＩＭＰＬＩＣＡＴＩＯＮＹａｎＹｕｅｈｕａＩｎｓｔｉｔｕｔｅｏｆＧｅｏｌｏｇｙ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅｉ... 相似文献
3.
《Scientia Geologica Sinica》1997,(2)
ＢＡＣＫＡＮＡＬＹＳＩＳＯＦＣＯＭＰＬＥＸＥＮＧＩＮＥＥＲＩＮＧＳＹＳＴＥＭTXＢＡＣＫＡＮＡＬＹＳＩＳＯＦＣＯＭＰＬＥＸＥＮＧＩＮＥＥＲＩＮＧＳＹＳＴＥＭＳＨａｎＢｅｉｃｈｕａｎＩｎｓｔｕｔｕｔｅｏｆＧｅｏｌｏｇｙ，ＡｃａｄｅｍｉａＳｉｎｉｃａ，Ｂｅ... 相似文献
4.
《Scientia Geologica Sinica》1997,(4)
ＷＥＢＧＥＯＧＲＡＰＨＩＣＩＮＦＯＲＭＡＴＩＯＮＳＹＳＴＥＭＳｏｎｇＸｉａｎｆｅｎｇＴｈｅＩｎｓｔｉｔｕｔｅｏｆＧｅｏｇｒａｐｈｙ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅｉｊｉｎｇ１００１０１ＴａｎＨａｉｑｉａｏＣｈｉｎａＵｎｉｖｅｒ... 相似文献
5.
《Scientia Geologica Sinica》1997,(3)
ＭＥＴＡＭＯＲＰＨＯＳＥＤＭＩＣＲＯＣＬＡＳＴＩＣＲＯＣＫＴＹＰＥＧＯＬＤＤＥＰＯＳＩＴＳＩＮＣＨＩＮＡＬｕＤｅｆｕＩｎｓｔｉｔｕｔｅｏｆＧｅｏｌｏｇｙ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅｉｊｉｎｇ１０００２９ＷａｎｇＸｉｕｚｈ... 相似文献
6.
《Scientia Geologica Sinica》1997,(4)
ＯＲＧＡＮＩＣＡＮＤＩＮＯＲＧＡＮＩＣＣＯＭＰＬＥＸＯＦＫＡＯＬＩＮＩＴＥＩＮＣＯＡＬＢＥＡＲＩＮＧＳＴＲＡＴＡＤｉｎｇＳｈｕｌｉＨｅｂｅｉＩｎｓｔｉｔｕｔｅｏｆＡｒｃｈｉｔｅｃｔｕｒａｌＳｃｉｅｎｃｅａｎｄｔｅｃｈｎｏｌｏｇｙ，Ｈａｎｄａｎ０５... 相似文献
7.
《Scientia Geologica Sinica》1997,(2)
ＣＯＡＬＰＯＲＰＨＹＲＩＮＳＣＯＡＬＰＯＲＰＨＹＲＩＮＳＬｕｏｆｕＬｉｕＵｎｉｖｅｒｓｉｔｙｏｆＰｅｔｒｏｌｅｕｍ，Ｂｅｉｊｉｎｇ１０２２００Ｇ．ＥｇｌｉｎｔｏｎＯｒｇａｎｉｃＧｅｏｃｈｅｍｉｓｔｒｙＵｎｉｔ，ＵｎｉｖｅｒｓｉｔｙｏｆＢｒｉｓｔｏｌ，... 相似文献
8.
《Scientia Geologica Sinica》1997,(3)
ＳＥＧＵＥＮＣＥＢＡＳＥＤＬＩＴＨＯＦＡＣＩＥＳＰＡＬＥＯＧＥＯＧＲＡＰＨＹＯＦＰＥＲＭＩＡＮＩＮＴＨＥＳＩＣＨＵＡＮＹＵＮＮＡＮＧＵＩＺＨＯＵＧＵＡＮＧＲＥＧＩＯＮＴｉａｎＪｉｎｇｃｈｕｎ，ＣｈｅｎＨｏｎｇｄｅ，ＱｉｎＪｉａｎｘｉｏｎｇａ... 相似文献
9.
《Scientia Geologica Sinica》1998,(1)
ＳＯＭＥＦＥＡＴＵＲＥＳＯＦＴＨＥＰＥＲＭＩＡＮＴＲＩＡＳＳＩＣＧＡＳＴＲＯＰＯＤＦＡＵＮＡＳＩＮＣＨＩＮＡＰａｎＹｕｎ－ｔａｎｇＧｒａｄｕａｔｅＳｃｈｏｌ,ＵｎｉｖｅｒｓｉｔｙｏｆＳｃｉｅｎｃｅａｎｄＴｅｃｈｎｏｌｏｇｙｏｆＣｈｉｎａ,Ｂｅｉｊ... 相似文献
10.
《Scientia Geologica Sinica》1997,(3)
ＲＥＥＦＡＮＤＧＲＡＶＩＴＹＦＬＯＷＳＥＤＩＭＥＮＴＳＯＮＰＥＲＭＩＡＮＳＬＯＰＥＳＩＮＴＨＥＳＩＣＨＵＡＮＹＵＮＮＡＮＧＵＩＺＨＯＵＧＵＡＮＧＸＩＲＥＧＩＯＮＱｉｎＪｉａｎｘｏｎｇ，ＣｈｅｎＨｏｎｇｄｅ，ＴｉａｎＪｉｎｇｃｈｕｎａｎｄＬｉＹｕ... 相似文献
11.
Yuanyuan Zhang Jaroslav Dostal Zehui Zhao Chang Liu Zhaojie Guo 《Gondwana Research》2011,20(4):816-830
The Liuyuan mafic and ultramafic rocks are exposed in Southern Beishan, which is along the southern branch of the Central Asian Orogenic Belt (CAOB). Zircon SHRIMP U–Pb dating showed that Liuyuan gabbros intruded during the early Permian (~ 270–295 Ma) coeval with the basalts and the ultramafic rocks were emplaced at about 250 Ma. The basalts are within–plate tholeiites with slight enrichment in light rare earth elements (LREE) relative to heavy rare earths (HREE) and small negative anomalies of Nb and Ta. Gabbros including olivine gabbros, olivine gabbronorites and troctolites are grouped into two: the cumulate gabbros are depleted in LREE and show small negative Nb and Ta anomalies but distinct positive Sr and Eu anomalies; non–cumulate gabbros resemble tholeiitic basalts. Lamprophyres and cumulate ultramafic rocks are characterized by large enrichment of LREE relative to HREE with depletion in Nb and Ta. The enriched Sr–Nd isotopic trend from DM towards the EM II end member component implies that the lithospheric mantle was progressively enriched with depth by the involvement of subducted crustal material due to the delamination of thickened mantle lithosphere after collision. The digestion of subducted crustal material into the mantle resulting in the metasomatized and enriched mantle is inferred to be an important process during crust–mantle interaction. 相似文献
12.
西昆仑库地蛇绿混杂岩由方辉橄榄岩和纯橄榄岩等地幔变质橄榄岩、豆荚状铬铁矿、堆晶橄榄岩、堆晶辉石岩和辉长岩、辉绿岩墙、块状和枕状玄武岩等组成。强亏损方辉橄榄岩为主的地幔岩组合,二辉石的低Al含量和铬尖晶石的高Cr#,以及岩石的富Mg、Ni和贫Al、Ca特征一致表明地幔橄榄岩类是经较高程度部分熔融后的地幔残余,与消减带之上蛇绿岩中的同类岩石相近。岩石富Rb、Ba、U、Th、LREE,说明地幔残余岩石受到了来自消减带的洋壳重熔组分的混染。堆晶岩以辉石岩和辉长岩为主,可能属PPG系列,指示岩浆是在消减带环境和含水条件下熔融的。辉长岩为低Ti蛇绿岩型,代表洋内弧后盆地早期环境或弧前环境。辉绿岩和玄武岩为洋中脊拉斑玄武岩和岛弧拉斑玄武岩的过渡类型;玄武岩和辉绿岩相比富Ba、Th、LREE,贫Ta,指示玄武岩较辉绿岩更多地受到来自消减带洋壳重熔组分的影响。库地蛇绿岩形成时的古构造环境是消减带之上的弧间或弧后盆地。 相似文献
13.
南秦岭勉县─略阳结合带蛇绿岩与岛弧火山岩地球化学及其大地构造意义 总被引：31，自引：1，他引：30
南秦岭勉县-略阳结合带中超基性岩类主要为方辉橄榄岩和纯橄榄岩,稀土特征为轻稀土亏损,铕富集型;辉绿岩均为轻稀土富集型。变质火山岩可区分为两种组合：一为轻稀土亏损的洋脊拉斑玄武岩,其Ti／V．Th／Ta、Th／Yb、Ta／Yb表明其为MORB型玄武岩,代表本区消失了的洋壳岩石,指示本区晚古生代一早中生代期间的一个古洋盆。另一类为岛弧火山岩组合,除岛弧拉斑玄武岩外,甚至还有大量中、酸性岛弧火山岩,它们并非洋壳的物质组成,而是大陆弧岩浆活动的产物。这表明勉略洋盆在晚古生代-早中生代期间曾经经历过一个较完整的有限洋盆的发生、发展与消亡过程,这期间秦岭已成为一独立的岩石圈微板块,其南缘具有活动大陆边缘的构造属性,秦岭并非华北与扬子陆块之间的简单碰撞产物。 相似文献
14.
Ultrabasic rocks in the Mianxian-Lueyang ophiolitic melange zone include harzburgite and dunite which exhibit LREE depletion with remarkable positive Eu anomaly.The diabase dike swarm shows LREE enrichment but slightly negative Eu anomaly.Metamorphosed volcanic rocks can be divided into two groups in terms of their REE geochemistry and trace element ratios of Ti/V,Th/Ta,Th/Yb and Ta/Yb.One is ths MORB-type basalt with LREE depletion,representing the fragments of oceanic crust and implying an association of the MORB-type ophiolite and an ancient ocean basin between the Qinling and Yangtze plates during the Middle Paleozoic-Early Mesozoic era.The oter comprises the island-arc volcanic rocks including tholeiitic basalt and a large amount of calc-alkaline intermediate-acic volcanic rock,which could not be the component of the ancient oceanic crust but the result of magmatism at the continental margin.This indicates that the Mianxian-Lueyang limited ocean basin had undergone a whole process of development,evolution and vanishing from Devonian-Cretaceous to Permian.And the Qinling area had becone an independent lithospheric microplate,on the southern side of which there were exhibited the tectonic characteristics of active continental margins during the Late Paleozoic-Early Mesozoic.That is to say.the Qinling cannot be simply considered as a result of collision between the Yangtze and North China plates. 相似文献
15.
《International Geology Review》2012,54(1):66-87
The Late Cretaceous Alihoca ophiolite in the Inner Tauride suture zone (ITSZ) of South-Central Turkey represents part of a single ophiolitic thrust sheet that originated from the Inner Tauride ocean. The ophiolite contains upper mantle peridotites, cumulate wehrlites, layered-to-isotropic gabbros, and microgabbroic-to-doleritic dikes. An ophiolitic mélange beneath the Alihoca ophiolite includes blocks of limestone, peridotite, dolerite, basalt, and deep-sea sedimentary rocks (radiolarite, chert) in a matrix comprising sheared serpentinite and mudstone. Isotropic gabbro and dolerite dike rocks show enrichment in Sr, K, Rb, Ba, and Th (LILE) and depletion of Ta, Nb, Zr, Ti, and Y (HFSE), indicating an island arc tholeiite (IAT) affinity. Relatively younger dolerite rocks display low TiO2 (<0.5 wt.%) contents, concave REE profiles with low HREE concentrations, and high LREE values, typical of boninitic affinities. The Alihoca ophiolite, hence, displays an IAT to boninitic geochemical progression in its magmatic evolution, reminiscent of many other Tethyan ophiolites in the region. It represents the remnant of a forearc oceanic crust, which developed during the early stages of subduction within the Inner Tauride ocean. Volcanic, volcano-sedimentary, and sedimentary rocks of the Uluk??la–Çamard? basin north of the ITSZ disconformably overlie the mafic-ultramafic rocks of the Alihoca ophiolite. Pillowed and massive lavas of the latest Cretaceous–Palaeocene Uluk??la Formation have alkaline basalt-to-basaltic andesite compositions, displaying relatively enriched LILE and LREE patterns with negative Nb and Ta anomalies. These geochemical features suggest that magmas of the Uluk??la–Çamard? volcanic rocks formed from partial melting of a metasomatized lithospheric mantle. This melting event was triggered by the influx of asthenospheric heat through a slab breakoff-induced window in the downgoing Tethyan oceanic lithosphere. 相似文献
16.
The intermediate–mafic–ultramafic rocks in the Jianzha Complex (JZC) at the northern margin of the West Qinling Orogenic Belt have been interpreted to be a part of an ophiolite suite. In this study, we present new geochronological, petrological, geochemical and Sr–Nd–Hf isotopic data and provide a different interpretation. The JZC is composed of dunite, wehrlite, olivine clinopyroxenite, olivine gabbro, gabbro, and pyroxene diorite. The suite shows characteristics of Alaskan-type complexes, including (1) the low CaO concentrations in olivine; (2) evidence of crystal accumulation; (3) high calcic composition of clinopyroxene; and (4) negative correlation between FeOtot and Cr2O3 of spinels. Hornblende and phlogopite are ubiquitous in the wehrlites, but minor orthopyroxene is also present. Hornblende and biotite are abundant late crystallized phases in the gabbros and diorites. The two pyroxene-bearing diorite samples from JZC yield zircon U–Pb ages of 245.7 ± 1.3 Ma and 241.8 ± 1.3 Ma. The mafic and ultramafic rocks display slightly enriched LREE patterns. The wehrlites display moderate to weak negative Eu anomalies (0.74–0.94), whereas the olivine gabbros and gabbros have pronounced positive Eu anomalies. Diorites show slight LREE enrichment, with (La/Yb)N ratios ranging from 4.42 to 7.79, and moderate to weak negative Eu anomalies (Eu/Eu1 = 0.64–0.86). The mafic and ultramafic rocks from this suite are characterized by negative Nb–Ta–Zr anomalies as well as positive Pb anomalies. Diorites show pronounced negative Ba, Nb–Ta and Ti spikes, and typical Th–U, K and Pb peaks. Combined with petrographic observations and chemical variations, we suggest that the magmatism was dominantly controlled by fractional crystallization and crystal accumulation, with limited crustal contamination. The arc-affinity signature and weekly negative to moderately positive εNd(t) values (−2.3 to 1.2) suggest that these rocks may have been generated by partial melting of the juvenile sub-continental lithospheric mantle that was metasomatized previously by slab-derived fluids. The lithologies in the JZC are related in space and time and originated from a common parental magma. Geochemical modeling suggests that their primitive parental magma had a basaltic composition. The ultramafic rocks were generated through olivine accumulation, and variable degrees of fractional crystallization with minor crustal contamination produced the diorites. The data presented here suggest that the subduction in West Qinling did not cease before the early stage of the Middle Triassic (∼242 Ma), a back-arc developed in the northern part of West Qinling during this period, and the JZC formed within the incipient back-arc. 相似文献
17.
错不扎蛇绿岩位于雅鲁藏布江缝合带西段北亚带,岩体呈北西-南东走向带状产出,主要由地幔橄榄岩和辉长岩脉组成。地幔橄榄岩主体为方辉橄榄岩,详细的矿物学及岩石地球化学研究表明,错不扎方辉橄榄岩中橄榄石为镁橄榄石,斜方辉石主要为顽火辉石,而单斜辉石主要为顽透辉石和透辉石,铬尖晶石具有高Al和高Mg(Mg#=60~70)特征。稀土配分图解显示其具有轻稀土亏损而重稀土富集的左倾型亏损地幔源区特征,(La/Yb)N=0.11~0.60,模拟结果显示其为经历了15%~20%部分熔融后的残余,与快速扩张大洋中脊环境下形成的深海橄榄岩的熔融程度(10%~22%)较为一致。此外,错不扎方辉橄榄岩轻稀土含量明显高于部分熔融模型中LREE的含量,而且,在微量元素原始地幔标准化图解中富集大离子亲石元素Rb、Sr和高场强元素Ta、Hf和Ti,这一特征指示错不扎方辉橄榄岩在大洋中脊环境形成后又受到后期俯冲带熔/流体的改造。结合南北两带不同蛇绿岩体构造环境的对比,笔者认为雅鲁藏布江西段南北两带蛇绿岩体具有相似的形成环境,两者在地理位置以及产状方面的差别可能是受到构造侵位的影响。 相似文献
18.
沂沭断裂带内高桥盆地早白垩世火山岩SiO2含量为51.97%～68.94%;由玄武粗安岩、 粗面岩和流纹岩组成;都属于碱性岩。岩石富集Rb、 Ba、 K等大离子亲石元素和轻稀土元素;相对亏损Nb、 Ta、 Ti等高场强元素和重稀土元素;并具有富集的Sr-Nd-Pb同位素组成。钾质粗面岩具有高稀土Cr、 Ni含量、 La/Yb、Sr/Y和Th/U高比值;这类似于华北克拉通东南缘早白垩世富集岩石圈来源的基性岩（如方城玄武岩、 沂南辉长岩）;其可能主要来源于富集岩石圈地幔部分熔融。与之相比;钠质玄武粗安岩具有低Cr、 Ni含量 、 87Sr/86Sr（t）、 Th/U和高εNd（t）值;表明它可能由岩石圈地幔熔体与软流圈物质混合而成。沂沭断裂带高桥盆地火山岩形成于岩石圈伸展背景下;沂沭断裂带的活动可能诱使软流圈物质的上涌;导致岩石圈地幔升温发生部分熔融;并为软流圈物质的上升提供了通道。 相似文献
19.
Yun-Peng Dong Mei-Fu Zhou Guo-Wei Zhang Ding-Wu Zhou Liang Liu Qi Zhang 《Journal of Asian Earth Sciences》2008,32(5-6):325
The Qinling Mountains in Central China mark a gigantic composite orogenic belt with a complex tectonic evolution involving multiple phases of rifting and convergence. This belt separates the North China and South China Blocks and consists of the South and North Qinling terranes separated by the Shangdan suture. The suture is marked by the Grenvillian Songshugou ophiolite along the southern margin of the North Qinling terrane, which is key to understanding the Proterozoic tectonic evolution of the belt. The ophiolite consists of highly metamorphosed ultramafic and mafic rocks. Three groups of meta-basalts are present: group 1 rocks are LREE depleted and have a MORB compositional affinity. Their low Ta/Yb ratios (<0.1) are consistent with high degrees of partial melting of a depleted asthenospheric mantle. Rocks of group 2 have higher TiO2 (1.63–2.08 wt%) and Ta/Yb ratios (>0.12), and display slight enrichment of LREE, suggesting that the original magmas were derived from a depleted mantle source mixed with some enriched material. Samples from group 3 are enriched in LREE and other incompatible elements (Ti, Zr, Ta, Nb), suggesting derivation from an enriched mantle source, possibly a plume. All the basalts have high εNd(t) (+4.2 to +6.9), variable εSr(t) and high 207Pb/204Pb and 208Pb/204Pb ratios for given 206Pb/204Pb ratios. These characteristics are compatible with formation at a mid-ocean ridge system above an anomalous Dupal mantle region. The mafic rocks have a Sm–Nd whole-rock isochron age of 1030 ± 46 Ma.The Songshugou ophiolite was emplaced onto the southern margin of the North Qinling terrane, an active continental margin from the Meso-Proterozoic to Neo-Proterozoic. 相似文献
20.
对海拉尔北部八大关地区塔木兰沟组安山岩进行的锆石U-Pb年代学、全岩地球化学等分析工作,揭示了塔木兰沟期安山岩构造背景及岩石成因意义,并探讨了蒙古-鄂霍次克缝合带构造演化史.LA-ICP-MS锆石U-Pb定年结果显示其形成于160.9~164.0 Ma.岩石地球化学特征表明,安山岩为高钾钙碱性岩石,轻重稀土分馏明显,（La/Yb）N=9.97~26.85,Eu呈微弱负异常-弱正异常（δEu=0.71~1.11）;微量元素以富集大离子亲石元素Rb、U、Th、K,强烈亏损Sr、P、Ti,相对亏损Nb、Ta为特征.岩浆可能来源于流体交代的地幔楔,并在岩浆演化过程中经历了明显的分离结晶作用.结合区域演化史,认为八大关地区塔木兰沟组安山岩形成于蒙古-鄂霍次克洋闭合后岩石圈的伸展环境. 相似文献