A NEW METHOD OF ESTIMATING DENUDATION RATES OF THE HIGH HIMALAYA BASED ON METAMORPHIC INDEX MINERALS IN THE SIWALIK MOLASSE

The erosion record of the high-grade metamorphic complex of the Himala ya is preserved in the Siwalik foreland molasse. Here we propose a new method for estimation of average denudation rates in the High Himalay a during the Miocene based on the first appearance of kyanite in the M iddle Siwaliks (beginning at similar to 11 Ma) and of sillimanite in t he Upper Siwaliks (at similar to 5 Ma) and from the fact that these me tamorphic index minerals were formed at depths of 21-24 km (thermobaro metric data) during the main Himalayan metamorphic event at similar to 23 Ma (geochronologic data).