West Antarctica: Problem child of Gondwanaland

Dalziel, Ian W. D.; Elliot, David H.

doi:10.1029/tc001i001p00003

Cited by 295 publications

(168 citation statements)

References 41 publications

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“…Often geological scenarios are in direct conflict with geophysical models for the same time period since unacceptable overlaps between the different continental fragments are introduced [Grunow, 1993b;Storey, 1991Storey, , 1996Dalziel and Elliot, 1982;Jokat et al, 1996]. Paleomagnetic investigations provided no unequivocal solution to that problem, since only a few Mesozoic rocks are exposed for paleomagnetic sampling [Grunow et al, 1987[Grunow et al, , 1991Grunow, 1993a].…”

Section: Introductionmentioning

confidence: 99%

Timing and geometry of early Gondwana breakup

et al. 2003

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[1] The Mesozoic opening history of the Southern Ocean between South America, Africa, and Antarctica is one of the largest gaps in knowledge on the evolution of this region. Competing geodynamic models were published during the last two decades to explain the geophysical and geological observations. Here we report on aeromagnetic data collected along the East Antarctic coast during five seasons. These data provide new constraints on the timing and geometry of the early Gondwana breakup. In the Riiser-Larsen Sea/ Mozambique Basin, the first oceanic crust between Africa and Antarctica formed around 155 Ma. In the west the Weddell Rift propagated from west to east with a velocity of 63 km/Myr between chrons M19N and M17N. At chron M14N, South America and Africa finally were split off the Antarctic continent. Stretching in the area of the South Atlantic started at the latest from 155 Myr onward. The different spreading velocities and directions of South America and Africa created at chron M9N the first oceanic crust in the South Atlantic. A new model indicates that the Karoo and Dronning Maud Land magmatism occurred well before any new ocean floor was created and therefore the first formation of new oceanic crust cannot directly be related to a plume interaction.

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Section: Introductionmentioning

confidence: 99%

Timing and geometry of early Gondwana breakup

et al. 2003

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“…Dalziel and Elliot, 1982;Storey, 1991;Grunow et al, 1991). Eagles et al (2004) illustrate that early Pacific-Antarctic separation evolved first as rifting and crustal extension along the present-day Bounty Trough between Chatham Rise and Campbell Plateau (Grobys et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Geophysical survey reveals tectonic structures in the Amundsen Sea embayment, West Antarctica

Gohl¹,

Teterin²,

Eagles³

et al. 2007

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The Amundsen Sea embayment of West Antarctica is in a prominent location for a series of tectonic and magmatic events from Paleozoic to Cenozoic times. Seismic, magnetic and gravity data from the embayment and Pine Island Bay (PIB) reveal the crustal thickness and some tectonic features. The Moho is 24-22 km deep on the shelf. NE-SW trending magnetic and gravity anomalies and the thin crust indicate a former rift zone that was active during or in the run-up to breakup between Chatham Rise and West Antarctica before or at 90 Ma. NW-SE trending gravity and magnetic anomalies, following a prolongation of Peacock Sound, indicate the extensional southern boundary to the Bellingshausen Plate which was active between 79 and 61 Ma.

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“…Author Proof (Dalziel and Elliot 1982). Each block has its own specific geological 224 history (Dalziel 1992).…”

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confidence: 99%