Antarctica and supercontinental evolution: clues and puzzles

• Published in: Earth and Environmental Science Transactions of the Royal Society of Edinburgh
• Main Author: Dalziel, Ian W. D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2013
• Subjects: General Earth and Planetary Sciences; General Environmental Science; Antarctic; East Antarctica; Pacific; Shackleton; Shackleton Range; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1017/s1755691012000096; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1755691012000096

ABSTRACT Antarctica has been known as the “keypiece” of the Gondwana supercontinent since publication of Du Toit's 1937 classic book Our Wandering Continents . It is also important to reconstruction of the early Neoproterozoic supercontinent Rodinia. Laurentia, with its circumferential late Precambrian rifted margins, can be regarded as the ‘keypiece’ of Rodinia. The S outh w est US– E ast A n t arctica (SWEAT) hypothesis suggested former juxtaposition of the Pacific margins of Laurentia and East Antarctica. Several new lines of evidence support this hypothesis in a revised form, but must be reconciled with opening of the Pacific Ocean basin predating amalgamation, not only of Gondwana, but even of today's East Antarctic craton. The sequence of events is envisaged to have been: (1) formation prior to 1·6 Ga of a craton, including Laurentia and the Mawson craton, that extended from South Australia along the present Transantarctic margin to the Shackleton Range; (2) suturing of southernmost Laurentia to the Kalahari craton along the Grenville, Namaqua–Natal–Maud orogenic belt ca. 1·0 Ga; (3) rifting of the East Antarctic margin (Mawson craton) from western Laurentia ca. 0·7 Ga; (4) pan-African suturing of the Mawson craton to southernmost Laurentia as Gondwana amalgamated, forming the ephemeral Pannotia supercontinent; and (5) end-Precambrian separation of Laurentia as Iapetus opened.