Correlation of Archaean and Palaeoproterozoic units between northeastern Canada and western Greenland: constraining the pre-collisional upper plate accretionary history of the Trans-Hudson orogen
Correlation of Archaean and Palaeoproterozoic units between northeastern Canada and western Greenland: constraining the pre-collisional upper plate accretionary history of the Trans-Hudson orogen
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加拿大东北部和格陵兰岛西部之间太古代和古元古代单元的相关性：限制跨哈德逊造山带碰撞前上板块增生历史
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发表时间：
2009
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通讯作者：
D. J. Scott
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作者：
M. St;J. V. van Gool;A. Garde;D. J. Scott
摘要根据加拿大东北部和格陵兰岛西部现有的构造地层学、年代学和构造数据，我们提出，跨哈得逊造山带的早期上板块历史的特征是一些增生构造事件，这导致了北方复合大陆（丘吉尔域）的成核和生长，然后与下板块上级克拉通发生终端碰撞和凹陷。在1.96 ~ 1.91 Ga之间，加拿大东北部（Ellesmere-Devon）和西格陵兰北方（Etah群-变质杂岩）都记录了沿雷克拉通北方边缘的古元古代变形和岩浆活动沿着。克拉通南部边缘主要是一个厚的大陆边缘序列的积累之间的c。2.16和1.89 Ga，在巴芬岛（Piling和Hoare Bay群）和西格陵兰（Karrat和Anap nunâ群）识别出相关组分。南北汇聚的开始导致了Meta Incognita微大陆在c.巴芬岛1.88-1.865 Ga。Aasiaat域的增生（微大陆片段？）在西格陵兰到Rae克拉通的过程中形成了Rinkian褶皱带。1.88佐治亚州随后北大西洋克拉通与复合Rae克拉通和Aasiaat域南缘的吸积-碰撞在c. 1.86和1.84 Ga（Nagssugtoqidian造山带），而北大西洋克拉通与拉布拉多的Meta Incognita微大陆东缘的碰撞则局限于c. 1.87-1.85 Ga（Torngat造山带）。1.845 Ga时，魁北克北方的海洋内Narsajuaq弧带（在格陵兰没有对应物）向复合丘吉尔域的南部边缘增生，随后在c时，下板块的上级克拉通（在格陵兰没有对应物）与复合丘吉尔域的上板块（在北方和魁北克东部）之间发生了最终碰撞。1.82-1.795 Ga。作为一个集合，在加拿大和格陵兰岛的增生构造事件记录碰撞前的下板上级克拉通约束的关键过程中的地壳增生的增长东北劳伦，特别是在上板丘吉尔域的trans-Hudson造山带在古元古代。这一时期的地壳融合可以直接与上板块亚洲大陆在始新世早期与下板块印度次大陆碰撞之前的地壳融合相比较。在这两种情况下，终端大陆碰撞之前，上板块地壳增生和碰撞的几个重要事件，因此可以被认为是碰撞造山作用的前兆和超大陆，如努纳（古元古代）和亚马逊（新生代）形成的标志。
Abstract Based on available tectonostratigraphic, geochronological, and structural data for northeastern Canada and western Greenland, we propose that the early, upper plate history of the Trans-Hudson orogen was characterized by a number of accretionary–tectonic events, which led to the nucleation and growth of a northern composite continent (the Churchill domain), prior to terminal collision with and indentation by the lower plate Superior craton. Between 1.96 and 1.91 Ga Palaeoproterozoic deformation and magmatism along the northern margin of the Rae craton is documented both in northeastern Canada (Ellesmere–Devon terrane) and in northern West Greenland (Etah Group–metaigneous complex). The southern margin of the craton was dominated by the accumulation of a thick continental margin sequence between c. 2.16 and 1.89 Ga, whose correlative components are recognized on Baffin Island (Piling and Hoare Bay groups) and in West Greenland (Karrat and Anap nunâ groups). Initiation of north–south convergence led to accretion of the Meta Incognita microcontinent to the southern margin of the Rae craton at c. 1.88–1.865 Ga on Baffin Island. Accretion of the Aasiaat domain (microcontinental fragment?) in West Greenland to the Rae craton resulted in formation of the Rinkian fold belt at c. 1.88 Ga. Subsequent accretion–collision of the North Atlantic craton with the southern margin of the composite Rae craton and Aasiaat domain is bracketed between c. 1.86 and 1.84 Ga (Nagssugtoqidian orogen), whereas collision of the North Atlantic craton with the eastern margin of Meta Incognita microcontinent in Labrador is constrained at c. 1.87–1.85 Ga (Torngat orogen). Accretion of the intra-oceanic Narsajuaq arc terrane of northern Quebec (no correlative in Greenland) to the southern margin of the composite Churchill domain at 1.845 Ga was followed by terminal collision between the lower plate Superior craton (no correlative in Greenland) and the composite, upper plate Churchill domain in northern and eastern Quebec at c. 1.82–1.795 Ga. Taken as a set, the accretionary–tectonic events documented in Canada and Greenland prior to collision of the lower plate Superior craton constrain the key processes of crustal accretion during the growth of northeastern Laurentia and specifically those in the upper plate Churchill domain of the Trans-Hudson orogen during the Palaeoproterozoic Era. This period of crustal amalgamation can be compared directly with that of the upper plate Asian continent prior to its collision with the lower plate Indian subcontinent in the early Eocene. In both cases, terminal continental collision was preceded by several important episodes of upper plate crustal accretion and collision, which may therefore be considered as a harbinger of collisional orogenesis and a signature of the formation of supercontinents, such as Nuna (Palaeoproterozoic Era) and Amasia (Cenozoic Era).