3-D numerical investigation of the mantle dynamics associated with the breakup of Pangea

Conference · Thu Oct 01 04:00:00 EDT 1992

DOI:https://doi.org/10.1007/978-94-015-8206-3_14· OSTI ID:10185390

Baumgardner, J R

Three-dimensional finite element calculations in spherical geometry are performed to study the response of the mantle with platelike blocks at its surface to an initial condition corresponding to subduction along the margins of Pangea. The mantle is treated as an infinite Prandtl number Boussinesq fluid inside a spherical shell with isothermal, undeformable, free-slip boundaries. Nonsubducting rigid blocks to model continental lithosphere are included in the topmost layer of the computational mesh. At the beginning of the numerical experiments these blocks represent the present continents mapped to their approximate Pangean positions. Asymmetrical downwelling at the margins of these nonsubducting blocks results in a pattern of stresses that acts to pull the supercontinent apart. The calculations suggest that the breakup of Pangea and the subsequent global pattern of seafloor spreading was driven largely by the subduction at the Pangean margins.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 10185390
• Report Number(s): LA-UR--92-2943; CONF-9106401--1; ON: DE93000796
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000
CONVECTION
EARTH CRUST
EARTH MANTLE
FINITE ELEMENT METHOD
GEOSCIENCES
MATHEMATICAL MODELS
SEA BED
SUBDUCTION ZONES
TECTONICS