Post-rift subsidence of the French Guiana hyper-oblique margin: from rift-inherited subsidence to Amazon deposition effect
Published:January 01, 2016
Francois Sapin, Mélanie Davaux, Massimo Dall’asta, Marjolaine Lahmi, Gautier Baudot, Jean-Claude Ringenbach, 2016. "Post-rift subsidence of the French Guiana hyper-oblique margin: from rift-inherited subsidence to Amazon deposition effect", Transform Margins: Development, Controls and Petroleum Systems, M. Nemčok, S. Rybár, S. T. Sinha, S. A. Hermeston, L. Ledvényiová
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The recent surge of exploration activities over distal margins, with the acquisition of more and more high-quality and deep seismic data, has led to enhance concepts of the deformation and subsidence history of passive margins in general and sheared margins in particular. The French Guiana sheared margin is very narrow. The thinning of the upper crust is accommodated by few major faults relayed by well-expressed transfer zones, giving a general oblique trend to the margin. Another possible effect of the shear component during the rifting is the presence in the distal domain of a Moho high. Its exhumation is coeval with the emplacement of a deltaic system coming from the Demerara Plateau, evidencing a probably important early subsidence of the margin. This early subsidence in the late-rifting stage is increased during the early drifting, when the thinned crust reached its isostatic/thermal equilibrium in the Cenomano-Turonian before suffering an important Late Cretaceous sedimentation load. In the Palaeogene, starving of the margin and significant uplifts in the Guiana Craton are observed, possibly resulting from the rise of the Purus Arch (Andes fore-bulge?). Finally, the Amazon deposition by the Late Miocene–Pliocene provoked a large subsidence in the distal domain.
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Transform Margins: Development, Controls and Petroleum Systems
This volume covers the linkage between new transform margin research and increasing transform margin exploration. It offers a critical set of predictive tools via an understanding of the mechanisms involved in the development of play concept elements at transform margins. It ties petroleum systems knowledge to the input coming from research focused on dynamic development, kinematic development, structural architecture and thermal regimes, together with their controlling factors. The volume does this by drawing from geophysical data (bathymetry, seismic, gravity and magnetic studies), structural geology, sedimentology, geochemistry, plate reconstruction and thermo-mechanical numerical modelling. It combines case studies (covering the Andaman Sea, Arctic, Coromandal, Guyana, Romanche, St. Paul and Suriname transform margins, the French Guyana hyper-oblique margin, the transtensional margin between the Caribbean and North American plates, and the Davie transform margin and its neighbour transform margins) with theoretical studies.