...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Asian earth sciences >Retrieval of P-T-t-d paths in a syn-metamorphic shear zone: Implications for P-T calculations and the Permian-Triassic orogeny on the Korean Peninsula
【24h】

Retrieval of P-T-t-d paths in a syn-metamorphic shear zone: Implications for P-T calculations and the Permian-Triassic orogeny on the Korean Peninsula

机译：同变质剪切带中P-T-t-d路径的反演：对朝​​鲜半岛P-T计算和二叠纪-三叠纪造山运动的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Crustal-scale shear zones developed on the boundaries of the Precambrian Gyeonggi Massif (GM) can play key role on understanding collisional orogeny during the Late Paleozoic to Early Mesozoic in the Korean Peninsula. Garnet schist formed on the boundary between the GM and Okcheon Metamorphic Belt (OMB) experienced contractional (D-n) and extensional (Dn+1) shearing combined with a clockwise pressure-temperature-deformation (P-T-d) path. Two distinct mineral assemblages were found in the schists, (1) garnet (pre- and/or syn-D-n) + staurolite (syn-D-n and/or inter D-n and Dn+1, and syn-Dn+1) + andalusite (syn-Dn+1)-bearing and (2) garnet (pre- and/or synD) + epidote-bearing assemblages, depending on bulk-rock compositions. Various compositions in the former assemblage and An(45-70) in the latter one) and texture of plagioclase resulted from bulk-rock compositions, heterogeneous strain and dissolution and precipitation during the multiple shearing. The P-T conditions estimated for the early contractional shearing (top-to-the-north reverse shear) are 560 degrees C-600 degrees C and 5.5-7.0 kbar based on the intersections between compositional isopleths for pre- and/or syn-D-n garnet and plagioclase (An(30-40) & An(45-55)) calculated in the MnO-Na2O-CaO-K2O-FeO-MgO-Al2O3-SiOr-H2O and MnO-Na2O-CaO-K2O-FeO-MgO-Al2O3-SiO2-H2O-TiO2-Fe2O3 systems. Subsequent extensional shearing (top-to-the-south normal shear) was characterized by recrystallization of fine-grained syn-Dn+1 staurolite with growth of syn-Dn+1 andalusite porphyroblasts during cooling and decompression to 560 degrees C and 3.5 kbar. The contractional and extensional shearing probably occurred at the Permian and the Late Triassic to Early Jurassic, respectively, based on the previous geochronological data. Consequently, inferred P-T-t-d paths on the GM-OMB boundary probably suggest not only crustal thickening followed by thinning, but also multiple amalgamations of several terranes.
机译：在前寒武纪京畿地块（GM）边界上发育的地壳规模剪切带在理解朝鲜半岛晚古生代至早中生代的碰撞造山运动中起着关键作用。在GM和Okcheon变质带（OMB）之间的边界上形成的石榴石片岩经历了收缩（D-n）和伸展（Dn + 1）剪切以及顺时针压力-温度-变形（P-T-d）路径。在片岩中发现了两种截然不同的矿物组合：（1）石榴石（前和/或syn-Dn）+人造石（syn-Dn和/或inter Dn和Dn + 1，以及syn-Dn + 1）+红柱石（ syn-Dn + 1）-轴承和（2）石榴石（pre-和/或synD）+附有附子的轴承，具体取决于大块岩石的成分。前者组合中的各种成分和后者中的An（45-70）以及斜长石的质地是由块岩成分，非均质应变以及多重剪切过程中的溶解和沉淀引起的。根据前-和/或同-Dn石榴石的组成等值线之间的交点，估计早期收缩剪切（从上到北的反向剪切）的PT条件为560°C-600°C和5.5-7.0kbar在MnO-Na2O-CaO-K2O-FeO-MgO-Al2O3-SiOr-H2O和MnO-Na2O-CaO-K2O-FeO-MgO-中计算出的斜长石（An（30-40）和An（45-55）） Al2O3-SiO2-H2O-TiO2-Fe2O3体系。随后的拉伸剪切（自上而下的法向剪切）的特征是细晶粒的syn-Dn + 1恒沸石重结晶，在冷却和减压至560摄氏度和3.5 kbar的过程中，syn-Dn + 1和红柱石成矿细胞的生长。根据先前的年代学数据，收缩和伸展剪切作用可能分别发生在二叠纪和三叠纪晚期至侏罗纪早期。因此，在GM-OMB边界上推断出的P-T-t-d路径可能不仅暗示地壳增厚然后变薄，而且还暗示了多个地层的多次合并。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号