|
Early Stages of Gondwana Break-Up |
1 Centro de Investigaciones Geológicas, La Plata University, Calle 1 No 644, 1900 La Plata, Argentina
2 British Antarctic Survey, c/o NERC Isotope Geosciences Laboratory, Keyworth Nottingham NG12 5GG, UK
The transcurrent Gastre Fault System in central Patagonia, which is closely associated with subvolcanic granite emplacement, is recognized as a major dextral shear-zone and geological boundary. We propose its equivalence to a Late Triassic-Jurassic precursor of the Aghulas Fracture Zone, allowing dextral displacement of the Southern Patagonian Block relative to the rest of South America during the earliest rifting phase of Gondwana break-up. This model could explain some of the inferred movement of the Falkland/Malvinas Islands and alleviate geometrical problems inherent in reconstructions of the South Atlantic region. It can also explain unique geological features of southern Patagonia, such as the Upper Triassic to Lower Jurassic calc-alkaline granitoids of the North Patagonian Massif and the extensive silicic volcanism of Mid-Late Jurassic times. The magmatism is seen as a consequence of the mechanism of Gondwana disintegration and it is not necessary to invoke a relationship to deep mantle structure or plume activity.
This article has been cited by other articles:
![]() |
C. W. Rapela, R. J. Pankhurst, C. M. Fanning, and F. Herve Pacific subduction coeval with the Karoo mantle plume: the Early Jurasssic Subcordilleran belt of northwestern Patagonia Geological Society, London, Special Publications, 2005; 246: 217 - 239. [Abstract] [PDF] |
||||
![]() |
P. F. Barker Falkland Plateau evolution and a mobile southernmost South America Geological Society, London, Special Publications, 1999; 153: 403 - 408. [Abstract] [PDF] |
||||
![]() |
S. R. Lawrence, M. Johnson, S. R. Tubb, and S. J. Marshallsea Tectono-stratigraphic evolution of the North Falkland region Geological Society, London, Special Publications, 1999; 153: 409 - 424. [Abstract] [PDF] |
||||
![]() |
M. K. Watkeys and D. Sokoutis Transtension in southeastern Africa associated with Gondwana break-up Geological Society, London, Special Publications, 1998; 135: 203 - 214. [Abstract] [PDF] |
||||
![]() |
M. L. Curtis and B. C. Storey A review of geological constraints on the pre-break-up position of the Ellsworth Mountains within Gondwana: implications for Weddell Sea evolution Geological Society, London, Special Publications, 1996; 108: 11 - 30. [Abstract] [PDF] |
||||
![]() |
B. C. Storey, A. P. M. Vaughan, and I. L. Millar Geodynamic evolution of the Antarctic Peninsula during Mesozoic times and its bearing on Weddell Sea history Geological Society, London, Special Publications, 1996; 108: 87 - 103. [Abstract] [PDF] |
||||
![]() |
P. C. Richards, R. W. Gatliff, M. F. Quinn, N. G. T. Fannin, and J. P. Williamson The geological evolution of the Falkland Islands continental shelf Geological Society, London, Special Publications, 1996; 108: 105 - 128. [Abstract] [PDF] |
||||