scholarly journals Summary of palaeomagnetic results from West Antarctica: implications for the tectonic evolution of the Pacific margin of Gondwana during the Mesozoic

1996 ◽  
Vol 108 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Vic Divenere ◽  
Dennis V. Kent ◽  
Ian W. D. Dalziel
2021 ◽  
Author(s):  
Tom Jordan ◽  
Teal Riley ◽  
Christine Siddoway

<p>West Antarctica developed as the tectonically active margin separating East Antarctica and the Pacific Ocean for almost half a billion years. Its dynamic history of magmatism, continental growth and fragmentation are recorded in sparse outcrops, and revealed by regional geophysical patterns. Compared with East Antarctica, West Antarctica is younger, more tectonically active and has a lower average elevation. We identify three broad physiographic provinces within West Antarctica and present their overlapping and interconnected tectonic and geological history as a framework for future study: 1/ The Weddell Sea region, which lay furthest from the subducting margin, but was most impacted by the Jurassic initiation of Gondwana break-up. 2/ Marie Byrd Land and the West Antarctic rift system which developed as a broad Cretaceous to Cenozoic continental rift system, reworking a former convergent margin. 3/ The Antarctic Peninsula and Thurston Island which preserve an almost complete magmatic arc system. We conclude by briefly discussing the evolution of the West Antarctic system as a whole, and the key questions which need to be addressed in future. One such question is whether West Antarctica is best conceived as an accreted collection of rigid microcontinental blocks (as commonly depicted) or as a plastically deforming and constantly growing melange of continental fragments and juvenile magmatic regions. This distinction is fundamental to understanding the tectonic evolution of young continental lithosphere. Defining the underlying geological template of West Antarctica and constraining its linkages to the dynamics of the overlying ice sheet, which is vulnerable to change due to human activity, is of critical importance.</p>


Author(s):  
V. D. Soloviev ◽  
◽  
V. G. Bakhmutov ◽  
I. N. Korchagin ◽  
T. P. Yegorova ◽  
...  

1990 ◽  
Vol 2 (3) ◽  
pp. 265-266
Author(s):  
F. Tessensohn ◽  
M.R.A. Thomson

The Shackleton Range occupies a key geological position in Antarctica (Fig. 1). Its location, at the edge of the continental craton between the mobile belts of the Transantarctic Mountains (TAM) and the stable platform of Dronning Maud Land (Neuschwabenland), and its geological constitution offer possibilities for: understanding the nature of the ‘Pacific’ margin of the Antarctic craton during the Palaeozoic, distinguishing between subduction- and collision-related tectonics at an ancient continental margin, and contributing to the debate on the relationship between East and West Antarctica. The structural orientation of the range, at right angles to the trend of the TAM, has puzzled geologists ever since its discovery.


2002 ◽  
Vol 107 (B12) ◽  
pp. EPM 5-1-EPM 5-19 ◽  
Author(s):  
Robert D. Larter ◽  
Alex P. Cunningham ◽  
Peter F. Barker ◽  
Karsten Gohl ◽  
Frank O. Nitsche

2016 ◽  
Vol 2 (7) ◽  
pp. e1600022 ◽  
Author(s):  
Lydian M. Boschman ◽  
Douwe J. J. van Hinsbergen

The oceanic Pacific Plate started forming in Early Jurassic time within the vast Panthalassa Ocean that surrounded the supercontinent Pangea, and contains the oldest lithosphere that can directly constrain the geodynamic history of the circum-Pangean Earth. We show that the geometry of the oldest marine magnetic anomalies of the Pacific Plate attests to a unique plate kinematic event that sparked the plate’s birth at virtually a point location, surrounded by the Izanagi, Farallon, and Phoenix Plates. We reconstruct the unstable triple junction that caused the plate reorganization, which led to the birth of the Pacific Plate, and present a model of the plate tectonic configuration that preconditioned this event. We show that a stable but migrating triple junction involving the gradual cessation of intraoceanic Panthalassa subduction culminated in the formation of an unstable transform-transform-transform triple junction. The consequent plate boundary reorganization resulted in the formation of a stable triangular three-ridge system from which the nascent Pacific Plate expanded. We link the birth of the Pacific Plate to the regional termination of intra-Panthalassa subduction. Remnants thereof have been identified in the deep lower mantle of which the locations may provide paleolongitudinal control on the absolute location of the early Pacific Plate. Our results constitute an essential step in unraveling the plate tectonic evolution of “Thalassa Incognita” that comprises the comprehensive Panthalassa Ocean surrounding Pangea.


2011 ◽  
Vol 31 (2) ◽  
pp. S85-S92 ◽  
Author(s):  
J. Vaughn Barrie ◽  
Sarah Cook ◽  
Kim W. Conway

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