Integration of Hinterland Low-Temperature Thermochronology with Flexural Modeling: A New Tool for Foreland Basin Analysis
D. J. Gombosi1 and D. L. Barbeau2
1Earth Sciences, Syracuse University, Syracuse, NY
2Geological Sciences, University of South Carolina, Columbia, SC
Time-temperature (t-T) pathways constructed from thermochronology of orogenic hinterlands can constrain the exhumational histories of mountain belts. When combined with erosion rate and geothermal gradient measurements or estimates, these pathways can ascertain the magnitudes and rates of rock-uplift of an orogen. Because rock-uplift data provide vital constraints on the kinematics and material flux in an orogen, thermochronology offers a powerful means of independently constraining the history of crustal loading that causes flexural subsidence and sediment accumulation in foreland basin systems. We examine this application of thermochronometry to the prediction of foreland basin architecture with a conceptual model, which we test on a cross-strike 2D profile of the petroliferous Magallanes/Austral foreland basin of Tierra del Fuego.
We combine thermochronometrically determined and spatially-averaged rock-uplift magnitudes with orogen-width estimations to constrain the approximate mass of hinterland loads at various periods in the studied orogen’s history. Using such palinspastically restored loading estimates, we use flexural modeling to predict the history of basin subsidence and associated sediment accumulation. Our modeled results agree reasonably with the study area’s welllog and seismic data as well as existing chronostratigraphic models for the basinfill. This method demonstrates the utility of regional thermochronometric surveys for predicting the distribution and dimensions of source, seal and reservoir facies in foreland basin systems. The collection of widespread areal thermochronometric data should enable 3D reconstruction of basin subsidence and prediction of basin-scale stratigraphic architecture.
AAPG Search and Discover Article #90087 © 2008 AAPG/SEG Student Expo, Houston, Texas