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Kenorland was one of the earliest supercontinents on Earth. Kenorland is believed to have formed during the Neoarchaean Era ~2.7 billion years ago (2.7 Ga) by the accretion of Neoarchaean cratons and the formation of new continental crust. Kenorland comprised what later became Laurentia (the core of today's North America and Greenland), Baltica (today's Scandinavia and Baltic), Western Australia and Kalaharia. Kenorland also formed a substantial and substantive part of Nena, the supercontinent associated with the Sudbury Basin Impact.〔(Youtube video )〕 Swarms of volcanic dikes and their paleomagnetic orientation as well as the existence of similar stratigraphic sequences permit this reconstruction. The core of Kenorland, the Baltic/Fennoscandian Shield, traces its origins back to over 3.1 Ga. The Yilgarn Craton (present-day Western Australia) contains zircon crystals in its crust that date back to 4.4 Ga. ==Formation== Kenorland was formed around 2.7 billion years ago (2.7 Ga) as a result of a series of accretion events and the formation of new continental crust (Halla, 2005). The accretion events are recorded in the greenstone belts of the Yilgarn Craton as metamorphosed basalt belts and granitic domes accreted around the high grade metamorphic core of the Western Gneiss Terrane, which includes elements of up to 3.2 Ga in age and some older portions, for example the Narryer Gneiss Terrane. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Kenorland」の詳細全文を読む スポンサード リンク
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