I had to change this view in the manner described in Vol. III of this work and on my orographic maps. On the map in I : I 000 000 I am afraid the Pabla Range has been drawn some ten miles too far south. But as I said before, both its situation and its general orography are unknown. The curious, nearly isolated snow-covered group of Do-tsänkang (vide two photos opposite to p. 2 90, Vol. III) belongs to this range. The Kyam-chu, the river of Amchok-tang, flows between the Pabla and the Nien-chen-tang-la.
A more detailed knowledge of this complicated world of mountains will certainly bring to light several other parallel ranges of lesser order. But even now I believe in the existence of one secondary range situated between the Pabla and the Nien-chen-tang-la. In its western section it is the water-parting between the Pashu-tsangpo (the river flowing eastwards from Chang-la-Pod-la), and Lenjo-chu, a tributary to the Mü-chu. Taribo, Kaso, Tsari and Takar are mountain regions on it. It is pierced by the upper Mü-chu in a transverse valley. Some 2 2 km. farther E. N. E. the Chesang-la, 5474 m. high, is situated on it. In a latitudinal valley south of it flows the Bup - ch u, a left tributary of the Mü - chu, and north of it is the latitudinal valley of Muva- chechen , also a left tributary of the Mü-chu. It acts as a water-parting between both. In the easternmost part of this range, which might be called the Chesang Range, there is the secondary pass of Kyang-la, 5000 m. high.
North of the Pabla Range and east of Shuru-tso there is a little range which may be called the Parvi - pu Range after a group of flat snow-peaks of this name (vide photo on opposite page). The Tarbung-la is situated in this range, 5267 m. high, and it is pierced by the Targo-tsangpo in a gorge probably narrow and uncomfortable, as the road sticks to the heigths N. E. of it.
The range running on the eastern shore of Dangra-yum-tso and N. E. of the valley of the lower Targo-tsangpo could be called the Largäp Range. In its northern section NAIN SING crossed it in Chuku-la, 505o m. high, and north of this pass he saw the peak Kandigar, 6290 m. high. The range is the water-parting between Dangra-yum-tso and Ngangtse-tso. It is chiefly meridional as are other ranges on both sides of the rift-valley, our second meridional line of violent compression. Along the Targo-tsangpo the range is well developed and seems to turn S. E. and east. However, with our present knowledge it is impossible to say with certainty anything regarding the orography of this district. It may be that the Largäp Range should rather be regarded as an immediate continuation of the Parvi - pu. If this be the case, the range is pierced by the Nagma-tsangpo, and shows a remarkable parallellism with the Targo - gangri , Targo - rigüt , Gangri - do and Umbu. In accordance with the ranges, the rift-valley goes in a zigzag , N. N. E.—S. S. W., N. N.W.—S. S. E., N. E.—S.W., and finally, at Amchok-tso, N. N. W.S. S. E. This also is a proof of the strong torsion and violent lateral compression to which the earth's crust has been exposed in this region.
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