Southern Tibet Detachment System at Khula Kangri, Eastern Himalaya: A Large-Area, Shallow Detachment Stretching into Bhutan?

A new map and cross sections of the Khula Kangri and Kankar Pünzum-Monlakarchung High Himalayan ranges in the Tibet-Bhutan frontier area are presented from integration of unpublished mapping from the summit section of Khula Kangri and new remote sensing together with previous mapping. The ranges define an orographic bifurcation of the High Himalaya that results in a north-south repetition of the main geological section and coincides with the morphological repetition. The Southern Tibet Detachment System that juxtaposes the Tethyan sedimentary rocks against the gneisses and granites of the High Himalayan Crystalline can be continuously traced around both ranges and is not imbricated. Postdetachment kilometer-scale flexure and faulting account for the features of the observed bifurcation. The true map extent of the Khula Kangri and Monlakarchung-Passalum granite batholiths is now apparent. We propose that the two plutons are part of the same originally continuous body.