A COMPARISON OF 1-D AND 2-D THERMO-TECTONIC MODELS EXAMINING THE VARISCAN RESPONSE TO CRUSTAL THICKENING AND THINNING IN NW IBERIA

Computer modeling has been used for several decades to explore the thermal effects of crustal thickening during orogeny and more recently to use thermal models to evaluate potential Pressure-Temperature-time paths of specific terrains that were proposed to explain data from structural, metamorphic, and geochronological studies. Originally restricted to one-dimensional (1-D) models, two-dimensional (2-D) models that include advection of heat through incremental tectonic and magmatic movements have become popular with the advent of faster and more accessible computing. One drawback of the 2-D models is that their added complexity requires a significant increase in computing time. As a result, a 1-D model can take less than 5 minutes to run while a comparable 2-D model requires several hours.

A 2-D model of the thermo-tectonic history of the Lugo Dome, northwestern Spain is compared to previously published results of 1-D modeling. Although the 2-D model includes incremental advection of heat by thrusting rather than instantaneous emplacement used in 1-D, the resultant thermal history is very similar to that obtained from 1-D models. It follows that, the advantage of more rapid computation using a 1-D model that allows for extensive testing of the effects of different parameterizations on model outcomes may be more valuable than minimal improvements in model histories obtained by working in two dimensions.