29 
part].] Lydehher ■, Geology of Laddk and dSeighhouring IHstnds. 
see that in Ladak portions of the slato series are sometimes locally altered into 
a dark-colored gneiss which overlies the massive lighter-colored gneiss, and the 
same may not improbably be the case with the Tashgam rocks. 
To the eastward of Di-as, the slaty rocks may be traced across the Sum river 
as far as a line running nearly from north-west to south-east through Mulhet- 
riing Station, where the rocks of the great Triassic series appear to be faulted 
against them. To the south and south-east the same .slates overlie the gneiss 
of Sum and Riindum, and were identified by Dr. Stoliczka as undoubted 
Silurians. If, as I infer from Dr. Stoliczka’s notes, the gneiss of Sura is over¬ 
laid conformably by the slates, the foi’mer may probably bo the same as the 
gneiss of Dras and the Shingo-Shigar river: this question will be discussed 
more fully in the sequel. The Suru Silurian slates have been traced by Dr. 
Stoliczka in a band I’unning south-soixth-east from Riindum to the south of 
Zanskar, and are there continuous with those of North Lahiil and Spiti, which 
will be refeiTod to again in the third section of this paper. 
Returning to the main axis of gneiss to the north of Tashgam, I proceed to 
trace its eastward extension, and to consider its relations to other rocks to the 
east. From the junction of the Dras with the Shingo-Shigar river, the gneiss 
extends to the south-east as far as Kargil and Chattu, where it is overlaid by the 
Tertiary series. From Kargil I have traced the gneiss down the Sura and Dras 
rivers as far as the Indus, but did not reach its northern limit. The gneiss in 
this district is sometimes fine-grained and dark-colox’ed, and at other times 
coarse-grained and light-colored. At Kargil a very massive light-colored gneiss, 
without any trace of stratification, underlies the darker and more distinctly stra¬ 
tified upper gneiss. 
From Kargil the southern boundary of the crystalline series runs in a gene¬ 
rally south-easterly direction.' It keeps to the south of the Indus till near the 
village of Dorgu, when it crosses to the northern bank. To the eastward of 
Dorgu the boundary forms a sinuous line along the bed of the Indus for some 
miles; it then runs at some distance to the north of the river, passing close to the 
villages of Skining, Pharka, Himis, and Ling: from the last-named place the 
boundary bears to the south-east, till it again joins the Indus at Pittak, south of 
Leh. To the south-east of Pittak the southern boundary of the crystallines 
follows approximately the course of the Indus, generally running somewhat to the 
north, and has beeu traced as far as a point due south of the Pangiir Lake. 
It now remains to say something of the composition, and relations to other 
rocks, of the Ladak crystallines. 
To the south-east of Kargil along the Indus valley the gneiss usually consists 
of the light-colored massive variety, and has generally a north-easterly dip, so 
that the older beds appear along the valley of the Indus and the newer towards 
the top of the Kailas range. 
The composition of the rock varies considerably; in most cases, indeed, the 
' The range on the right bank of the Indus in Laddk has been termed by General Cunning- 
h.im (“Ladak,” !>. 43) the “ Kailas range,” a name which I adojit here: in the “Manual of tlie 
Geology of India” this range is called the “ Ladak range.” This range forms a dominant branch 
of the range north of the Manasarowar Lake. 
