The Model

Abstract

Geochronological data from some of the important tectonic events of the Himalaya are summarized. A brief introduction of pre-Himalayan structures, including the basic rocks and four phases of acid magmatism, is given along with distribution of volcanic rocks in the Himalaya. Distribution of significant structural features, which form the basis for the proposed model are described. These include evidence of seismicity below the plane of basal detachment, inconsistency between surface and subsurface fold geometries, arcuate shape of the Himalaya as a primary structure, locking of the prominent Himalayan thrusts followed by formation of strike-slip faults, occurrence of younger rocks on the thrust hanging wall, and formation of superposed folds, which indicate maximum compression in E–W direction. The model is based on inversion tectonics and explains many of the previously unexplained features. Finally, the recent concept of tectonics versus climate is briefly discussed. It is concluded that the Himalayan structures are a result of gigantic tectonic forces that drive the plates and make the Indian plate to subduct beneath the Tibetan plate.