Gabo Valley, a N-S trending extensional valley in southern Tibet, forms part of a chain of similar valleys that extends roughly northward from the Himalayas for 150 km. Within the chain, each of the valleys are laterally offset from one another and are connected by NE-trending transfer faults with probable left-slip displacement. Gabo Valley itself is marked by numerous active fault scarps. The morphology of the valley and the distribution of faults and alluvial fans indicate the valley was formed by two fault blocks that rotated in opposite directions; a northern block on the east side and beneath the valley rotated down-to-the-west and a southern block on the west side and under the valley rotated down-to-the-east. A smooth transition zone appears to connect the two fault blocks beneath the central part of the valley. The most active faults, which are presumably the faults with the greatest displacement and that accommodate much of the block rotation, occur at the ends of the valley and merge with the NE-trending transfer faults.
