GRAPHIC APPROACH TO DETERMINATION OF HYDROCARBON MATURATION IN OVERTHRUST TERRAINS.

A simple graphic technique, which combines Lopatin diagrams with theoretical models of temperatures in overthrust regimes, allows one to develop relatively detailed models for the timing of hydrocarbon maturation in overthrust terrains. These models provide the critical combination between rigorous consideration of thermal perturbations and simplification necessary for routine application. The approach described here is applicable not only in cases of simple overthrusting at the surface, but can also be modified to include the effects of multiple thrusting events, sheets thrust in the subsurface, and post-thrusting erosion. All of these models provide critical constraints on the timing of maturation and migration, as well as information on the maturity of potential source rocks. Refs.