HR: 11:45h
AN: T21E-06    [PDF]
TI: Fault System Evolution and Fault Reactivation During Large-Scale Distributed Deformation in Continental Lithosphere
AU: * Roy, M
EM: mroy@unm.edu
AF: Department of Earth and Planetary Sciences, University of New Mexico, MSC-03-2040, 1 Univ. of New Mexico, Albuquerque, NM 87131 United States
AB: Deformation within continents involves multi-scale responses such as localized brittle faulting (mainly in the upper crust) and more distributed deformation commonly modeled as elastic, viscous, or visco-elastic behavior (within the lower crust and upper mantle). This study investigates the interaction between localized faulting and distributed elastic flexure within intra-plate extensional settings. The geodynamic models presented are inspired by deformation observed at the Rio Grande rift, where Neogene extension appears to have been controlled by pre-existing lithospheric-scale heterogeneities and where pre-existing (Laramide) structures show evidence of rift-related extensional reactivation. The idealized models explore the evolution of new and pre-existing brittle faults in an upper crustal layer during flexural bending of the lithosphere. Particular attention is devoted to understanding how flexure interacts with faulting within both the hanging wall and footwall blocks of asymmetric half-graben (such as the Espanola or Albuquerque basins of the central Rio Grande rift). The model results suggest that the combination of flexure and faulting within a bending plate can explain certain enigmatic features of the central Rio Grande rift, including topographically high rift-flanks on both the hanging wall and footwall blocks of asymmetric basins.
DE: 8010 Fractures and faults
DE: 8020 Mechanics
DE: 8109 Continental tectonics--extensional (0905)
DE: 8120 Dynamics of lithosphere and mantle--general
DE: 8159 Rheology--crust and lithosphere
SC: Tectonophysics [T]
MN: 2003 Fall Meeting