Collaborative Research: Dynamic Models for the Tectonic Evolution of the Transantarctic Mountains and the Ross Embayment

This is a proposal to address many aspects of the formation of the Transantarctic Mountains (TAM) and the Ross Embayment, which (as documented in the geologic record) remain poorly understood, little studied or controversial. For example, the volume of uplifted rocks of the TAM is about five times greater than any other rift flank uplift worldwide; or it remains unclear why the larger magnitude extension during the Cretaceous produced relatively little denudation in the TAM, while the minor Cenozoic extension produced more. The wide rifting of the Ross Embayment in the Cretaceous with accompanying TAM denudation has not yet been modeled, and existing models explain only the main Cenozoic uplift phase of the TAM. New constraints on the geology history and the density and seismic structure of the TAM and Ross Embayment combined with recently improved numerical techniques prompt to propose evaluation of ideas for the tectonic and erosional development of the region using dynamic models of lithospheric deformation. It is now possible to combine numerical models of large-scale (100 to 1000 kilometers) mechanical and thermal evolution of the lithosphere with consideration of the small-scale development of individual faults. The small-scale deformation capability means that geologic data, like fission track studies, can be compared to model predictions. The proposed approach is to first study models for separate components of the problems that may relate to the tectonic development of the TAM and Ross Embayment, and then integrate the results later. The tight integration of geophysical and geological data with numerical models will be critical to determine which sequence of processes is likely to have shaped the region. The proposal outcome will provide the framework for a better understanding of the mechanisms responsible for the formation of the TAM and the mechanical behavior of the Ross Embayment lithosphere. The proposal objectives match with science goals of the international Antarctic Margin Drilling initiative (ANDRILL), as well as may provide a valuable input to the scientific goals of the new international research initiative on Antarctic Climate Evolution (ACE). Generally, the proposed modeling will contribute to the understanding of geologic processes and how such a long and high mountain range was formed and maintained. Broader impacts of this proposal include providing an opportunity for graduate students to participate in the modeling project, to include summer students in the ongoing analysis through the Lamont summer intern program, give presentations at the annual Open House that are usually well attended by the public. The team plans to create an educational Web site with model animations and make the proposed research a part of outreach activities at both Lamont and Syracuse Universities.