Reply to comment by MP Searle and RJ Phillips (2009) and RR Parrish (2009) on: 'Does the Karakoram fault interrupt mid-crustal channel flow in the western Himalaya?' by Mary L. Leech, Earth and Planetary Science Letters 276 (2008) 314-322 Discussion

摘要

My paper “Does the Karakoramfault interrupt mid-crustal channel flowin the western Himalaya?” proposes, as the title indicates, a model based on geological and geophysical evidence to explain differences between the Himalaya west of and east of the eastern termination of the Karakoram fault. Granites in the western Himalaya are substantially older than the youngest granites exposed in the east; the youngest granites in the west are found in the Karakoram shear zone and have ages that coincide with or post-date the onset of motion on the Karakoramfault. Magnetotelluric data showthat mid-crustal melts extend from beneath the Himalaya to well north of the Indus–Yarlung suture zone but the volume of melt in thewest is significantly less than in the east. The crustal-scale Karakoram fault may have tapped midcrustal melts and prevented southward flow of channel granites since the Early Miocene.