Mpr. Light et al., THE TECTONOSTRATIGRAPHIC DEVELOPMENT OF PATAGONIA, AND ITS RELEVANCE TO HYDROCARBON EXPLORATION, Journal of petroleum geology, 16(4), 1993, pp. 465-481
The history of terrane accretion along the Pacific margin, that formed
the Palaeozoic basement to Patagonia, is discussed. This pre-existing
NW-trending basement fabric was periodically reactivated by shear str
ess, resulting from near-continuous oblique Pacific subduction process
es, producing pull-apart and extensional grabens. During the Permo-Tri
assic, an asymmetric passive rift developed east of an eastwardly-dipp
ing simple shear, following the axis of the proto-South Atlantic, and
was invaded by a shallow sea. The Falkland (Malvinas) Microplate is sh
own to have docked with Patagonia in the Early/Mid Jurassic. Clockwise
symmetrical rotation and crustal deformation of the Falklands (Malvin
as) and other microplates between east-west trending, dextral strike-s
lip faults controlled the development of the southern transverse Atlan
tic margin basins. Early restricted deposition in these basins (Early
Jurassic-Neocomian) led to the deposition of proved continental source
-reservoir associations. Rifting and transverse dextral strike-slip sh
earing propagated northwards, up the axis of the Atlantic. As terrane
collision progressed. the rift zone widened SWwards to the Pacific and
NEwards to the Colorado Basin. Atlantic sea-floor spreading in the Ne
ocomian, and subsequent thermal sag of the Atlantic margin, is shown t
o have culminated in a major transgression in the Maastrichtian, which
formed a regional seal for hydrocarbons.