THE INTERDEPENDENCE OF DEFORMATIONAL AND THERMAL-PROCESSES IN MOUNTAIN BELTS

Crustal temperatures within collisional orogens are anomalously high c ompared with temperatures at comparable depths in stable continents, w hich is evidence of thermal processes that are fundamental to orogenes is. These temperatures can be explained by the redistribution of crust enriched in heat-producing elements through the accretion of crust fr om the down-going plate to the upper plate and surface erosion. With t he use of geologically reasonable rates, the model results predict hig h temperatures (over 600 degrees C) and inverted upper-plate geotherms (about 100 degrees C over 20 kilometers) at shallow depths (20 to 40 kilometers) by 25 to 35 million years after collision, This study emph asizes the interdependence of deformational, surficial, and thermal pr ocesses.