Upper mantle viscosity and dynamic subsidence of curved continental margins

Author(s)

Sacek, Victor ^[1] ; Ussami, Naomi ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508090 Sao Paulo - Brazil

• Document type: Journal article
• Source: NATURE COMMUNICATIONS; v. 4, JUN 2013.
• Web of Science Citations: 1

Abstract

Continental rifting does not always follow a straight line. Nevertheless, little attention has been given to the influence of rifting curvature in the evolution of extended margins. Here, using a three-dimensional model to simulate mantle dynamics, we demonstrate that the curvature of rifting along a margin also controls post-rift basin subsidence. Our results indicate that a concave-oceanward margin subsides faster than a convex margin does during the post-rift phase. This dynamic subsidence of curved margins is a result of lateral thermal conduction and mantle convection. Furthermore, the differential subsidence is strongly dependent on the viscosity structure. As a natural example, we analyse the post-rift stratigraphic evolution of the Santos Basin, southeastern Brazil. The differential dynamic subsidence of this margin is only possible if the viscosity of the upper mantle is >2-3 x 10(19) Pa s. (AU)

• FAPESP's process: 09/50493-8 - Crustal and lithospheric mantle models under the Paraná and Chaco-Paraná basins by merging satellite gravity gradiometry, terrestrial gravimetry and geomagnetic and electromagnetic soundings
• Grantee: Icaro Vitorello
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 11/10400-0 - Tectonic, climatic and erosional evolution in convergent margins: a numerical approach
• Grantee: Victor Sacek
• Support Opportunities: Scholarships in Brazil - Post-Doctoral