Towards integrating results from electrical resistivity models into geodynamic modeling to better understand the evolution of the lithosphere.

Abstract

Thermo-mechanical numerical modeling can provide valuable insights by simulating the temporal evolution of dynamic processes. The simulation model can be evaluated against the available observational evidence and physically plausible mechanisms can be further explored. To better understand the evolution of the lithosphere, multi-disciplinary results can be integrated into the geodynamic modeling, creating more realistic and reliable models. What’s more, such modeling offers an excellent opportunity to test various hypotheses and to constrain the possible ranges of parameters. By systematically varying physical parameters, their influence and control on dynamic tectonic processes can be tested. Here we present work that uses Central Mongolia as a case study. This location is an ideal natural laboratory for studying surface deformation and intraplate uplift because of its high-elevation plateau in a location in the continental interior — far from tectonic plate boundaries. Intracontinental surface deformation is enigmatic, and the underlying mechanisms responsible are not fully understood. However, because deformation solely by means of tectonic plate motion is not possible in an intraplate setting, crust-mantle interactions (e.g., driven by mantle convection) are likely required to explain the origin and evolution of intracontinental deformation. Explanations for surface uplift in the continental interior include: 1. hot, buoyant, deep-rooted mantle plumes; 2. crustal thickening from mafic magmatic underplating; 3. broad-scale mantleflow and thermal convection processes that produce dynamic topography; and 4. small-scale asthenospheric upwelling prompted by isolated lithospheric removal. We use self-consistent thermo-mechanical numerical modeling to investigate a subset of the latter explanation: lithospheric removal by delamination or a Rayleigh-Taylor instability. We explore the conditions under which delamination can occur and investigate the timing and amplitude of the consequent surface deformation.