Metamorphic Evolution of the Main Central Thrust, Nepal

University Of South Carolina At Columbia, Columbia SC

Investigators

Abstract

Kohn EAR-0073803 The Himalaya are the product of collision between India and Asia, and the Main Central Thrust (MCT) is a major fault that has accommodated Indo-Asian convergence. A longstanding problem in understanding the dynamics of the MCT is explaining its "inverted" metamorphic sequence: ordinarily pressure (P) and temperature (T) increase downward, yet across the MCT, structurally higher rocks preserve higher metamorphic P's and T's than rocks below. Different explanations for formation and preservation of inverted metamorphism imply different pressure-temperature-time (P-T-t) histories for each rock. The purpose of this study is to characterize P-T-t paths in a transect across the MCT and evaluate competing hypotheses. This work is important for understanding both the Indo-Asian collision and the tectonic significance of inverted metamorphic sequences in general.