The Heart of China revisited: II Early Paleozoic (ultra)high‐pressure and (ultra)high‐temperature metamorphic Qinling orogenic collage
The Heart of China revisited: II Early Paleozoic (ultra)high‐pressure and (ultra)high‐temperature metamorphic Qinling orogenic collage
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DOI：
10.1002/tect.20056
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发表时间：
2013-07
期刊：
影响因子：
4.2
通讯作者：
T. Bader;L. Franz;L. Ratschbacher;C. Capitani;A. Webb;Zhao Yang;J. Pfänder;M. Hofmann;U. Linnem
中科院分区：
文献类型：
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作者：
T. Bader;L. Franz;L. Ratschbacher;C. Capitani;A. Webb;Zhao Yang;J. Pfänder;M. Hofmann;U. Linnem
具有多个（超）高压（（U）HP）和（超）高温（（U）HT）变质事件的造山带为大洋和大陆相互作用提供了复杂但生动的记录。“中国心脏”秦岭造山拼贴的早古生代历史提供了至少三个（U）高压和两个（U）高温变质事件的快照。大洋和大陆区域的残留物的保存，以及≥ 1.1亿年的岩浆活动记录，使我们能够重建导致这种不同变质作用的过程。在此，我们首先阐明的压力-温度-时间（P-T-t）演化的早古生代（U）HP和（U）HT事件，通过细化的岩相描述和P-T估计，评估出版，并采用新的U/Th-Pb锆石，独居石，钛铁矿，和40 Ar-39 Ar多硅白云母地质年代学来确定岩浆和变质事件。然后，我们探讨了变质和岩浆事件是如何在构造上相互联系的，以及它们如何阐明秦岭造山拼贴中各种杂岩之间的亲缘关系。我们认为，中新元古代地壳碎片-秦岭复合体-局部俯冲-增生事件，涉及俯冲，洋弧形成，弧后扩张沿着其北方边缘，和mantle-楔折返和扩张脊俯冲沿着其南部边缘。
Orogens with multiple (ultra)high‐pressure ((U)HP) and (ultra)high‐temperature ((U)HT) metamorphic events provide a complex but telling record of oceanic and continental interaction. The Early Paleozoic history of the “Heart of China,” the Qinling orogenic collage, offers snapshots of at least three (U)HP and two (U)HT metamorphic events. The preservation of remnants of both oceanic and continental domains together with a ≥110 Myr record of magmatism allows the reconstruction of the processes that resulted in this disparate metamorphism. Herein, we first illuminate the pressure‐temperature‐time (P‐T‐t) evolution of the Early Paleozoic (U)HP and (U)HT events by refining the petrographic descriptions and P‐T estimates, assess published, and employ new U/Th‐Pb zircon, monazite, and titanite, and 40Ar‐39Ar phengite geochronology to date the magmatic and metamorphic events. Then we explore how the metamorphic and magmatic events are related tectonically and how they elucidate the affinities among the various complexes in the Qinling orogenic collage. We argue that a Meso‐Neoproterozoic crustal fragment—the Qinling complex—localized subduction‐accretion events that involved subduction, oceanic‐arc formation, and back‐arc spreading along its northern margin, and mtantle‐wedge exhumation and spreading‐ridge subduction along its southern margin.