Unroofing the Ladakh Batholith: constraints from autochthonous molasse of the Indus Basin, NW Himalaya

The Indus Molasse records orogenic sedimentation associated with uplift and erosion of the southern margin of Asia in the course of ongoing India–Eurasia collision. Detailed field investigation clarifies the nature and extent of the depositional contact between this molasse and underlying basement units. We report the first dataset on detrital zircon U–Pb ages and Hf isotopes, and apatite U–Pb ages for the autochthonous molasse in the Indus Suture Zone. A latest Oligocene depositional age is proposed based on the youngest detrital zircon U–Pb age peak and is consistent with published biostratigraphic data. Multiple provenance indicators suggest exclusively northerly derivation with no input from India in lowermost parts of the section. Results provide constraints on the uplift and erosion history of the Ladakh Range subsequent to the initial India–Asia collision.