Linking collisional and accretionary orogens during Rodinia assembly and breakup: Implications for models of supercontinent cycles
Linking collisional and accretionary orogens during Rodinia assembly and breakup: Implications for models of supercontinent cycles
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DOI：
10.1016/j.epsl.2016.05.049
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发表时间：
2016-09-01
影响因子：
5.3
通讯作者：
Murphy, J. Brendan
中科院分区：
文献类型：
--
作者：
Cawood, Peter A.;Strachan, Robin A.;Murphy, J. Brendan
大陆碎片的周期性聚集和分散是固体地球历史上的一个特征。地球动力学的驱动程序，这种循环活动被推断为自上而下的过程，在板块边界或自下而上的过程，地幔对流，特别是地幔柱，或两者的某种组合的近地表岩石圈应力。对Rodinian地壳块体地质历史的分析表明，超大陆的内部裂陷和解体与俯冲的开始和其周边增生造山带的发展有关。因此，分手是一个自上而下的煽动过程。在新元古代早期，辐合点最初位于东北部和北方劳伦特附近，然后延伸到亚马逊河流域和非洲的外侧，包括阿瓦隆尼亚-卡多米亚，在新元古代中期，辐合点位于西伯利亚外侧和波罗的海北方东部的弧区（近似于760 Ma）。Rodinia外围俯冲的持续时间与超大陆内部岩石圈伸展的时间相吻合，包括约1000年前太平洋的打开。760 Ma和东劳伦大陆裂谷的开始。劳伦蒂亚、波罗的海和西伯利亚周围的被动边缘序列的最终发展直到新元古代晚期到古生代早期才完成（约2000年）。570-530 Ma），这与引起冈瓦纳大陆的会聚板块相互作用的终止以及随后俯冲带向该超大陆外围的迁移相对应。外部俯冲和内部伸展之间的时间联系表明，解体是由超大陆外围沿着的增生构造驱动的自上而下的过程开始的。与地幔柱有关的岩浆活动可能会出现在分裂期间的特定时间和特定地点，但不是主要的驱动力。Rodinia记录的大陆组装和分散与努纳，冈瓦纳和盘古大陆的比较表明分组为两个超循环，努纳和冈瓦纳只经历了部分或没有分裂阶段之前，他们分别纳入Rodinia和盘古大陆。只有在这最后的组装阶段之后，超级大陆才经历了完全的分散。(C)2016作者（S）由爱思唯尔公司出版。这是一篇开放获取的文章，使用CC BY许可证（http：//creativecommons.org/licenses/by/4.0/）。
Periodic assembly and dispersal of continental fragments has been a characteristic of the solid Earth for much of its history. Geodynamic drivers of this cyclic activity are inferred to be either top-down processes related to near surface lithospheric stresses at plate boundaries or bottom-up processes related to mantle convection and, in particular, mantle plumes, or some combination of the two. Analysis of the geological history of Rodinian crustal blocks suggests that internal rifting and breakup of the supercontinent were linked to the initiation of subduction and development of accretionary orogens around its periphery. Thus, breakup was a top-down instigated process. The locus of convergence was initially around northeastern and northern Laurentia in the early Neoproterozoic before extending to outboard of Amazonia and Africa, including Avalonia-Cadomia, and arcs outboard of Siberia and eastern to northern Baltica in the mid-Neoproterozoic (similar to 760 Ma). The duration of subduction around the periphery of Rodinia coincides with the interval of lithospheric extension within the supercontinent, including the opening of the proto-Pacific at ca. 760 Ma and the commencement of rifting in east Laurentia. Final development of passive margin successions around Laurentia, Baltica and Siberia was not completed until the late Neoproterozoic to early Paleozoic (ca. 570-530 Ma), which corresponds with the termination of convergent plate interactions that gave rise to Gondwana and the consequent relocation of subduction zones to the periphery of this supercontinent. The temporal link between external subduction and internal extension suggests that breakup was initiated by a top-down process driven by accretionary tectonics along the periphery of the supercontinent. Plume-related magmatism may be present at specific times and in specific places during breakup but is not the prime driving force. Comparison of the Rodinia record of continental assembly and dispersal with that for Nuna, Gondwana and Pangea suggests grouping into two supercycles in which Nuna and Gondwana underwent only partial or no break-up phase prior to their incorporation into Rodinia and Pangea respectively. It was only after this final phase of assembly that the supercontinents then underwent full dispersal. (C) 2016 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).