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新疆天山石炭—二叠纪大规模岩浆成矿事件与形成机制探讨 总被引：1，自引：0，他引：1
天山地质构造演化复杂,多阶段演化中岩浆活动与成矿作用规模并不均衡。而石炭-二叠纪却是天山成矿带大规模岩浆活动和金属成矿作用的"爆发"期。本研究紧紧围绕岩浆铜镍矿床、斑岩型铜(钼)矿床及火山岩型磁铁矿矿床,从含矿岩体的岩浆起源、岩浆演化及成矿特点,系统研究地球深部相应岩浆活动的地质过程。通过典型矿床的深入剖析,建立相应矿床类型的成矿模式,破解制约找矿突破的控制因素,系统阐述了板块构造与地幔柱体制叠加并存的地质特征与成矿表现。联系塔里木地幔柱的活动特点和成矿表现,将其与天山造山带三类主要矿床类型建立关联,对比岩石学、年代学及地球化学研究,发现天山成矿带成矿类型与塔里木地幔柱及板块构造存有密切关系,可能是两种构造体制叠加并存的结果。塔里木克拉通深部熔融的地幔物质,围绕刚性塔里木克拉通边缘不断上涌,并与表壳物质发生交换,随着板块俯冲的持续和减弱,深部上涌的地幔物质不断加强,先后形成因深部地幔物质多寡而金属聚集的不同矿床类型。该地幔柱形成时深部过程与成矿作用认识模型的建立,极大地推进了板块构造、地幔柱与岩浆成矿作用的研究,同时可为天山及邻区找矿突破提供借鉴和指导。 相似文献
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新疆磁海超大型铁矿区基性岩与铁成矿关系密切,是认识大规模铁成矿及其背景的关键.磁海铁矿区基性岩以辉绿岩为主,辉绿岩中断裂-裂隙控制板状铁矿脉群,单颗粒锆石U-Pb法测得206Pb/238U平均年龄为263.8±3.6 Ma(n＝11,MSWD=1.3),与二叠纪塔里木、东天山造山带、北山构造-成矿带等区域基性岩同时代.磁海铁矿区基性岩球粒陨石标准化微量元素蛛网图较平坦,Sr、Ba显示弱富集,Nb略亏损,球粒陨石标准化的REE配分曲线平坦,岩浆起源于亏损软流圈地幔,与其所在区域的北山构造-成矿带、东天山造山带、塔里木等地的基性岩均属碱性-钙碱性系列,它们的微量元素组成相近,岩浆性质相似,成生关系密切.磁海铁矿区基性岩可能是二叠纪地幔柱成因塔里木大火成岩省的组成部分,大规模铁成矿于地幔柱背景,北山构造-成矿带可能是塔里木地幔柱的一枝. 相似文献
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新疆东部新元古代晚期和古生代构造格局及其演变 总被引：134，自引：4，他引：134
基于笔者近20年来对新疆东部地质构造的研究和对前人地质地球物理资料的深入分析，本文系统讨论了新疆东部新元古代晚期和古生代的地壳形成与演化。该区古生代的构造单元被划分为阿尔泰地块、额尔齐斯断裂带、东准噶尔古生代造山带、准噶尔地块、东天山造山带和库鲁克塔格地块。该区古生代地壳构造演化包括震旦纪-石炭纪洋陆格局的变迁、石炭纪末至二叠纪后碰撞壳幔相互作用等两个阶段。其洋陆格局的变迁包括古生代早期萨彦洋、早古生代阿尔曼太尔洋、晚古生代卡拉麦里洋、古生代北天山洋和南天山洋的打开与关闭，其中两个天山洋盆可能为一个洋盆，大体上可以对比为中亚地区的古亚洲洋北支斋桑洋，阿尔曼太洋和卡拉麦里洋可能为西伯利亚古陆的边缘洋盆；而古亚洲洋南支的乌拉尔一南天山洋向东是否延伸到新疆东部，还有待于进一步研究。新疆东部的后碰撞构造演化包括三期重大地质事件：①300Ma前后的以中酸性为主的大规模岩浆活动；②280Ma前后的包括幔源岩浆在内的双峰式岩浆活动；⑧二叠纪中晚期(可能延续到三叠纪)的大规模地壳走滑运动。在此基础上，对新疆东部新元古代晚期和古生代构造演化与古亚洲洋演变的关系进行了探讨，并对仍然存在的主要相关问题进行了总结和归纳。 相似文献
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新疆东部-甘肃北山地区二叠纪玄武岩对比研究及其构造意义 总被引：5，自引：7，他引：5
通过对新疆东部三塘湖盆地、甘肃北山柳园地区以及邻区二叠纪玄武岩的地球化学特征对比研究，认识到新疆东部-甘肃北山地区及邻区二叠纪形成的系列断陷带内，同期产生的玄武岩具有不同的地球化学特征和岩浆来源，其形成的统一动力学机制主要是可能由于造山带增厚的岩石圈大范围拆沉而导致的大范围亏损地幔部分熔融岩浆和源自上、下地幔边界的小型地幔柱岩浆的作用。这种地幔柱不是核幔边界深部地幔柱的成因，而可能是早期俯冲洋壳的分离掉落后，中亚造山带范围内可能在上、下地幔之间存在更广泛的部分熔融岩浆的原因。由造山带增厚岩石圈大范围拆沉作用而导致的大范围亏损地幔部分熔融岩浆和源自上、下地幔边界的小型地幔柱岩浆的作用，可能是中亚造山带二叠纪深部壳幔作用最壮观的表现方式。同时也以大范围玄武岩喷发、裂谷、大规模后造山幔源花岗岩和超镁铁岩的侵位以及大规模成矿作用而成为独特的“中亚型造山带”而有别于其它造山带。 相似文献
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摘要：文中以板块构造理论为指导思想,以大量地质、物探、化探、遥感资料为依据,在全面分析前人对东天山造山带板块缝合线的认识基础上,重新厘定研究区准噶尔-哈萨克斯坦板块与塔里木板块缝合带的位置。经研究确定：东天山造山带康古尔塔格和阿齐克库都克两条断裂之间所夹持的区域,为准噶尔-哈萨克斯坦板块和塔里木板块陆 陆碰撞的缝合带,即康古尔塔格-阿齐克库都克碰撞缝合带。该碰撞缝合带既有板块边界划分意义,又有实体物质组成和特定结构、构造及其演化历史的独立构造单元,也是东天山地区重要的多金属成矿带,故该带对东天山造山带Cu、Ni、Au、Ag等多金属矿产的形成和空间分布起着重要的控制作用。 相似文献
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中国—吉尔吉斯天山成矿单元划分及其特征 总被引：1，自引：0，他引：1
中国—吉尔吉斯天山地处中亚天山造山带中段,是古亚洲构造域的重要组成部分,地质构造复杂,矿产资源丰富。在收集境内、外大量地质、矿产资料及图件的基础上,通过近年来对研究区内地层、构造、岩浆及矿产的研究,在大地构造单元划分基础上对研究区内天山进行了成矿单元划分,划分出北天山—伊犁、中天山和南天山—塔里木3个成矿省,进一步划分为22个成矿带和58个成矿亚带,总结了各成矿单元的地质及矿产特征,为天山成矿带矿产勘查和地质大调查工作部署提供有益的思路和依据。 相似文献
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西天山位于中亚增生型造山带的西南缘,夹于准噶尔地块和塔里木克拉通之间.西天山造山带的构造演化与天山洋的俯冲?关闭过程密切相关.西天山地质构造复杂,成矿作用独特,既可形成与活动陆缘有关的斑岩铜金矿和火山?沉积岩型铁锰矿,也可发育与伸展构造有关的海底热水沉积型铅锌矿和浅成低温热液型金矿等多个集中区.西天山地质构造演化和成矿作用一直是地质学家关注和研究的热点,近年来的地质找矿和基础研究工作也取得一系列重大进展,但同时也存在一些急待解决的问题.本文通过对区域地质背景、沉积建造、岩浆演化、成矿地质特征与物质来源、控矿因素等方面资料的综合研究,认为西天山造山带从前寒武纪到晚古生代经历了古陆边缘裂解、洋?陆俯冲增生、陆?陆碰撞及后造山伸展等地质过程;与此相应形成了多个成矿区带,主要包括:（1）哈尔达坂前寒武纪古陆边缘裂陷盆地环境的铅锌成矿带,（2）与博罗科努古生代洋?陆俯冲、碰撞?碰撞后伸展环境有关的金铜铅锌多金属成矿带,（3）与阿吾拉勒晚古生代岛弧?弧后盆地有关的铁多金属成矿带,（4）那拉提古生代岛弧金铜多金属成矿带.在此基础上建立了西天山主要成矿区带的成矿模式,厘定了与西天山沉积建造?构造活动?岩浆活动有关的成矿序列,总结了西天山铁铜铅锌金等优势矿产时空结构模型. 相似文献
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中国西北大陆岩石圈类型、岩石学结构及其意义 总被引：3，自引：0，他引：3
根据西北地区的地质和地球物理特征,区分出中国西北大陆以准噶尔和塔里木为代表的克拉通型岩石圈和造山带型岩石圈,而造山带型岩石圈又可以区分为以额济纳旗为代表的古生代造山带型岩石圈(老物质新结构)和包括天山、阿尔泰山、昆仑山在内的新生代造山型岩石圈(老物质新结构);依据岩石学方法、壳幔演化模型和造山带形成过程以及地震波速与岩石化学成分之间的关系,建立相应类型岩石圈的壳幔岩石学结,讨论了不同岩石圈类型的壳幔物质结构、地壳和岩石圈地幔厚度的地质含义及其找矿意义. 相似文献
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塔里木盆地与天山山脉晚新生代盆山耦合机制 总被引：10，自引：0，他引：10
根据塔里木盆地北缘地质构造几何学和运动学资料、油气勘探地震剖面、人工地震测深、地震层析成像以及地热资料,提出了塔里木盆地、准噶尔盆地岩石圈地幔在天山岩石圈之下碰撞并发生拆沉的盆山耦合机制的概念模型。由于印藏碰撞,青藏高原的北部前缘岩石圈地幔与塔里木盆地岩石圈地幔形成V字形碰撞结构,推动塔里木地块的高强度岩石圈向北运动并俯冲到天山岩石圈之下,以水平俯冲作用在中天山北缘岩石圈之下与准噶尔盆地向南俯冲的岩石圈地幔碰撞,并发生后剥拆离。塔里木岩石圈俯冲的过程中,形成库车再生前陆盆地和再生前陆冲断带以及再生天山山脉。冲断量约为塔里木俯冲量的20％。这一盆山耦合模型可以解释盆地构造、盆地沉降、山脉隆升、岩石圈深部构造和热特征。 相似文献
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Reassessment of petrogenesis of Carboniferous-Early Permian rift-related volcanic rocks in the Chinese Tianshan and its neighboring areas 总被引：8，自引：0，他引：8
The Carboniferous Early Permian rill-related volcanic successions.covering large areas in the Chinese Tianshan and its adjacent areas.make up a newly recognized important Phanerozoic large igneous province in the world.which can be further divided into two sub-provinces:Tianshan and Tarim. The regional unconformity of Lower Carboniferous upon basement or pre-Carboniferous rocks.the ages (360—351 Ma) of the youngest ophiolite and the peak of subduction metamorphism of high pressure-low temperature metamorphic belt and the occurrence of Ni-Cu-bearing mafic-ultramatic intrusion with age of—352 Ma and A-type granite with age of～358 Ma reveal that the final closure of the Paleo Asian Ocean might lake place in the Early Mississippian.Our summation shows that at least four criteria.being normally used to identify ancient asthenosphere upwelling(or mantle plumes),are met for this large igneous province:(1) surface uplift prior to magmatism:(2) being associated with continental ifting and breakup events:(3) chemical characteristics of asthenosphere(or plume) derived basalts;(4) close links to large-scale minerali/alion and the uncontaminaled basalts,being analogous to those of many "ore-bearing" large igneous provinces.display Sr-Nd isotopic variations between plume and EMI geochemical signatures.These suggest that a Carboniferous asthenosphere upwelling and an Early Permian plume played the central role in the generation of the Tianshan—Tarim(central Asia) large igneous province. 相似文献
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《Gondwana Research》2013,24(4):1316-1341
Subduction-related accretion in the Junggar–Balkash and South Tianshan Oceans (Paleo-Asian Ocean), mainly in the Paleozoic, gave rise to the present 2400 km-long Tianshan orogenic collage that extends from the Aral Sea eastwards through Uzbekistan, Tajikistan, Kyrgyzstan, to Xinjiang in China. This paper provides an up-to-date along-strike synthesis of this orogenic collage and a new tectonic model to explain its accretionary evolution.The northern part of the orogenic collage developed by consumption of the Junggar–Balkash Ocean together with Paleozoic island arcs (Northern Ili, Issyk Kul, and Chatkal) located in the west, which may have amalgamated into a composite arc in the Paleozoic in the west and by addition of another two, roughly parallel, arcs (Dananhu and Central Tianshan) in the east. The western composite arc and the eastern Dananhu and Central Tianshan arcs formed a late Paleozoic archipelago with multiple subduction zones. The southern part of the orogenic collage developed by the consumption of the South Tianshan Ocean which gave rise to a continuous accretionary complex (Kokshaal–Kumishi), which separated the Central Tianshan in the east and other Paleozoic arcs in the west from cratons (Tarim and Karakum) to the south. Cross-border correlations of this accretionary complex indicate a general southward and oceanward accretion by northward subduction in the early Paleozoic to Permian as recorded by successive southward juxtaposition of ophiolites, slices of ophiolitic mélanges, cherts, island arcs, olistostromes, blueschists, and turbidites, which are mainly Paleozoic in age, with the youngest main phase being Late Carboniferous–Permian. The initial docking of the southerly Tarim and Karakum cratons to this complicated late Paleozoic archipelago and accretionary complexes occurred in the Late Carboniferous–Early Permian in the eastern part of the Tianshan and in the Late Permian in the western part, which might have terminated collisional deformation on this suture zone. The final stages of closure of the Junggar–Balkash Ocean resembled the small ocean basin scenario of the Mediterranean Sea in the Cenozoic. In summary, the history of the Altaids is characterized by complicated multiple accretionary and collisional tectonics. 相似文献
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In this paper we present a review of mineral systems in northern Xinjiang,NW China,focussing on the Tianshan,West and East Junggar and Altay orogenic belts,all of which are part of the greater Central Asian Orogenic Belt(CAOB).The CAOB is a complex collage of ancient microcontinents,island arcs,oceanic plateaux and oceanic plates,which were amalgamated and accreted in Early Palaeozoic to Early Permian times.The establishment of the CAOB collage was followed by strike-slip movements and affected by intrap... 相似文献
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Khromykh S. V. Semenova D. V. Kotler P. D. Gurova A. V. Mikheev E. I. Perfilova A. A. 《Geotectonics》2020,54(4):510-528
Studies of volcanic rocks in orogenic troughs of Eastern Kazakhstan were carried out. The troughs were formed at late-orogenic stages of evolution of Hercynian Altai collision system. Volcanic rocks are represented by basalts, andesites, dacites and rhyolites. Based on geochemical and isotopic data, the basalts and andesites derived from mafic magmas that formed as a result of partial melting of garnet peridotites in the upper mantle under the orogen. U–Pb zircon data prove two volcanic stages: more-scaled Middle Carboniferous (~311 Ma) and less-scaled Early Permian (297–290 Ma). Basalts and andesites in lower parts of the orogenic troughs and independent dacite-rhyolite structures were formed at the Middle Carboniferous stage. Parental mafic magmas were formed as a result of partial melting of mantle substrates in local transtensional zones along large shear faults. The formation of dacites and rhyolites could have been caused by partial melting of crustal substrates under effect of mafic magmas. Transtensional movements in the lithosphere of orogenic belts may indicate the beginning of collapse of orogens. A smaller volume of basalts and andesites formed at the Early Permian stage. Geochemical data prove the independent episode of partial melting in upper mantle. Synchronous basalts and andesites also appeared at wide territory in Tian Shan, Central Kazakhstan, and Central and Southern Mongolia. Early Permian volcanism indicates general extension of the lithosphere at the postorogenic stages. Large-scaled Early Permian mafic and granitoid magmatism in Central Asia has been interpreted in recent years as the Tarim Large Igneous Province caused by Tarim mantle plume activity. Thus, the extension of the lithosphere and associated volcanism in the Early Permian can be an indicator of the onset of the plume–lithosphere interaction process.
相似文献16.
塔里木和中亚造山带西段二叠纪大火成岩省的两类地幔源区 总被引：3，自引：0，他引：3
对塔里木和中亚造山带西段二叠纪玄武质岩石地质、年龄、元素地球化学、同位素组成的系统总结表明,二叠纪火成岩在分布面积、岩石类型(以玄武岩占绝对优势)、活动时间(以275Ma左右为峰期)等方面均与世界典型的大火成岩省一致,将其命名为巴楚大火成岩省(Bachu LIP)。元素和同位素地球化学特征表明,塔里木玄武岩来自长期富集的岩石圈地幔,来源深度为60~80km。塔里木基性岩墙和超镁铁-镁铁杂岩的原始岩浆可能来自软流圈地幔(OIB)部分熔融。中亚造山带西段的玄武岩、基性岩墙和超镁铁-镁铁杂岩主要来自被俯冲带熔体交代的强烈亏损的岩石圈地幔,其中部分地区可能有软流圈物质的加入,如东天山和阿勒泰南缘高Ti系列的玄武质岩石。根据元素和同位素地球化学资料,将巴楚大火成岩省分为2个地幔省(mantle domain),即塔里木省和中亚省。这2个不同地幔省的成矿系列也有显著的差异,塔里木省为钒-钛磁铁矿矿床,而中亚则以铜-镍-(铂族金属)硫化物矿床为主,成矿作用的差异和岩浆地幔源区的差异是完全对应的。综合地质、地球化学和成矿作用,认为巴楚大火成岩省的形成和二叠纪地幔柱密切相关。 相似文献
17.
塔里木和中亚造山带西段二叠纪大火成岩省的两类地幔源区 总被引：7，自引：2，他引：5
对塔里木和中亚造山带西段二叠纪玄武质岩石地质、年龄、元素地球化学、同位素组成的系统总结表明,二叠纪火成岩在分布面积、岩石类型(以玄武岩占绝对优势)、活动时间(以275Ma左右为峰期)等方面均与世界典型的大火成岩省一致,将其命名为巴楚大火成岩省(Bachu LIP)。元素和同位素地球化学特征表明,塔里木玄武岩来自长期富集的岩石圈地幔,来源深度为60～80km。塔里木基性岩墙和超镁铁-镁铁杂岩的原始岩浆可能来自软流圈地幔(OIB)部分熔融。中亚造山带西段的玄武岩、基性岩墙和超镁铁-镁铁杂岩主要来自被俯冲带熔体交代的强烈亏损的岩石圈地幔,其中部分地区可能有软流圈物质的加入,如东天山和阿勒泰南缘高Ti系列的玄武质岩石。根据元素和同位素地球化学资料,将巴楚大火成岩省分为2个地幔省(mantledomain),即塔里木省和中亚省。这2个不同地幔省的成矿系列也有显著的差异,塔里木省为钒-钛磁铁矿矿床,而中亚则以铜-镍-(铂族金属)硫化物矿床为主,成矿作用的差异和岩浆地幔源区的差异是完全对应的。综合地质、地球化学和成矿作用,认为巴楚大火成岩省的形成和二叠纪地幔柱密切相关。 相似文献
18.
塔里木盆地西北缘与南天山早-中二叠世盆山耦合特征 总被引：2，自引：1，他引：1
通过对塔里木盆地西北缘及相邻南天山造山带的早-中二叠世岩相古地理、构造和岩浆作用的分析表明,塔里木盆地西北缘在早-中二叠世由于地幔柱作用而导致玄武质岩浆活动,南天山造山带内部则发育几乎同时代的碰撞后花岗岩.盆山结合部位早-中二叠世的沉积中心处于不断沉降的状态,而且沉积中心逐渐向塔里木地块之上迁移.南天山在早-中二叠世碰撞后伸展背景下的隆升作用导致塔里木岩石圈向南天山之下发生陆内俯冲作用,在山前形成类似周缘前陆盆地的构造环境,山前沉积中心相当于周缘前陆盆地系统的前渊相带.塔里木盆地内部早二叠世的地幔柱活动与南天山的碰撞后伸展作用没有明显的相关关系,但是南天山在早-中二叠世的碰撞后伸展作用则与塔里木盆地西北缘的沉积-构造作用具有良好耦合关系. 相似文献
19.
The research on Paleozoic tectonics and endogenic metallogeny in the Tianshan-Altay region of Central Asia is an important and significant project. The Altay region, as a collision zone of the Early Paleozoic(500–397 Ma), and the Tianshan region, as a collision zone of the early period in the Late Paleozoic(Late Devonian-Early Carboniferous, 385–323 Ma), are all the result of nearly N-S trending shortening and collision(according to recent magnetic orientation). In the Late Devonian-Early Carboniferous period(385–323 Ma), regional NW trending faults displayed features of dextral strike-slip motion in the Altay and Junggar regions. In the Tianshan region, nearly EW-trending regional faults are motions of the thrusts. However, in the Late Carboniferous-Early Permian period(323–260 Ma), influenced by the long-distance effect induced from the Ural collision zone, those areas suffered weaker eastward compression, the existing NW trending faults converted into sinistral strike-slip in the Altay and Junggar regions, and the existing nearly E-W trending faults transferred into dextral strike-slip faults in the Tianshan region. The Rocks of those regions in the Late Carboniferous-Early Permian period(323–260 Ma) were moderately ruptured to a certain tension-shear, and thus formed a number of world famous giant endogenic metal ore deposits in the Tianshan-Altay region. As to the Central Asian continent, the most powerful collision period may not coincide with the most favorable endogenic metallogenic period. It should be treated to "the orogenic metallogeny hypothesis" with caution in that region. 相似文献