Continental growth and reworking on the edge of the Columbia and Rodinia supercontinents; 1.86–0.9 Ga accretionary orogeny in southwest Fennoscandia
Continental growth and reworking on the edge of the Columbia and Rodinia supercontinents; 1.86–0.9 Ga accretionary orogeny in southwest Fennoscandia
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DOI：
10.1080/00206814.2014.958579
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发表时间：
2015-09
影响因子：
2.6
通讯作者：
N. Roberts;T. Slagstad
中科院分区：
文献类型：
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作者：
N. Roberts;T. Slagstad
从古元古代晚期到新元古代早期的地质历史主要是由超大陆哥伦比亚的形成，以及它的分裂和重新合并成下一个超大陆Rodinia。在全球范围内，主要的造山事件与这两个超级大陆的形成有关，而伸展的记录通常与分裂事件有关。这里介绍的是一个简要的地质演化西南芬诺斯坎迪亚在约。1.9-0.9 Ga周期。这一地区记录了一个漫长的历史，大陆增长和改造的长期生活增生造山带。大陆生长的三个主要时期被定义为跨斯堪的纳维亚火成岩带（1.86-1.66 Ga），哥特式（1.66-1.52 Ga）和Telemarkian（1.52-1.48 Ga）域。1.47-1.38 Ga Hallandian-Danopolonian时期的特征是俯冲带和覆盖板块的重组，大陆碰撞的证据有限。在随后的1.38-1.15 Ga的时间间隔，该地区被解释为位于内侧的收敛边缘，今天没有保存和托管岩浆活动和沉积有关的内侧伸展事件。1.15-0.9 Ga时期是Sveconorbital造山作用的主体，标志着这个长寿的增生造山带的结束，并具有显着的地壳变形，变质作用和岩浆作用。撞击的压头，典型的亚马逊河流域，通常被推断为广泛的Sveconorbenormogenesis的原因，但这仍然是不确定的。另一种解释是造山作用仅仅表现为俯冲、俯冲加积、地壳增厚以及陆壳的埋藏和折返，沿着加积边缘。在中元古代，芬诺斯坎迪亚西南部是一个更大的增生造山带的一部分，该造山带生长在哥伦比亚超大陆的边缘，并包括劳伦蒂亚和亚马逊河流域。沿着西太平洋的会聚边缘链是元古代地壳生长和构造作用的最佳模拟。
Geological history from the late Palaeoproterozoic to early Neoproterozoic is dominated by the formation of the supercontinent Columbia, and its break-up and re-amalgamation into the next supercontinent, Rodinia. On a global scale, major orogenic events have been tied to the formation of either of these supercontinents, and records of extension are commonly linked to break-up events. Presented here is a synopsis of the geological evolution of southwest Fennoscandia during the ca. 1.9–0.9 Ga period. This region records a protracted history of continental growth and reworking in a long-lived accretionary orogen. Three major periods of continental growth are defined by the Transscandinavian Igneous Belt (1.86–1.66 Ga), Gothian (1.66–1.52 Ga), and Telemarkian (1.52–1.48 Ga) domains. The 1.47–1.38 Ga Hallandian–Danopolonian period featured reorganization of the subduction zone and over-riding plates, with limited evidence for continental collision. During the subsequent 1.38–1.15 Ga interval, the region is interpreted as being located inboard of a convergent margin that is not preserved today and hosted magmatism and sedimentation related to inboard extensional events. The 1.15–0.9 Ga period is host to Sveconorwegian orogenesis that marks the end of this long-lived accretionary orogen and features significant crustal deformation, metamorphism, and magmatism. Collision of an indenter, typically Amazonia, is commonly inferred for the cause of widespread Sveconorwegian orogenesis, but this remains inconclusive. An alternative is that orogenesis merely represents subduction, terrane accretion, crustal thickening, and burial and exhumation of continental crust, along an accretionary margin. During the Mesoproterozoic, southwest Fennoscandia was part of a much larger accretionary orogen that grew on the edge of the Columbia supercontinent and included Laurentia and Amazonia amongst other cratons. The chain of convergent margins along the western Pacific is the best analogue for this setting of Proterozoic crustal growth and tectonism.