our journey towards Le. By crossing the Tunglung
pass, we had again gained the eastern slope of the ridge
dividing the waters of the. Zanskar from those of the
Indus. The Giah stream flows towards the latter
river with a north-easterly course, and two marches of
little more than seven miles each, brought us to the
banks of the Indus at a village called Upshi. For the
first mile after leaving Giah, the valley was somewhat
open, with steep banks of alluvial conglomerate; it then
contracted rather suddenly into a narrow ravine, with
steep rocky walls, composed of highly inclined strata of
conglomerate and sandstone. Owing to the diminished
elevation, the vegetation was considerably more recognizable
than it had been for the last week, and several
shrubby plants were seen which had long been absent.
Ephedra was common in the crevices of the rocks, and
the Tibetan rose and a small shrubby lonicera grew on
the gravelly banks of the little stream.
At Miru, a considerable village where we encamped,
the valley expanded into a little plain, filled as usual with
alluvium, and covered with cultivation. A few poplar-
trees occurred in the village. The ravine contracted
immediately below this place, and was, if possible, more
narrow and rocky than the day before, as the little stream
had to be crossed not less than four or five times in as
many miles, on small wooden bridges of rough planks.
A very beautiful Labiate shrub, a species oi'Perowskia,
with bright blue flowers, which I afterwards found very
abundant in the Indus valley from 12,000 to 8000 feet,
was here met with for the first time. Close to its junction
with the Indus, the ravine expanded into an open
plain, well covered with houses and enclosures, with
scattered poplar and willow trees, as well as a few apricots,
and traversed by canals of irrigation conducted from
the little Giah rivulet. The Indus is here not more than
forty feet wide, flowing swiftly over large boulders, and
quite unfordable.
Throughout the whole course of this very remarkable
gorge by which we descended from Giah, the rock continued
to be conglomerate, alternating with strata of
sandstone and of a very friable slate. The conglomerate
was extremely hard, and generally of a dark brown
colour. The matrix, which had often a semi-vitrified
appearance, was not less hard than the enclosed stones,
which were all rounded and very various in size and
composition, jasper rock, granite, and quartz being all
seen. The sandstone which accompanied the conglomerate
varied much in colour, various shades of red, brown,
and green being predominant. It was also extremely
hard. These strata, which were highly inclined, often
nearly vertical, were in general well marked, in conséquence
of the beds of hard sandstone and conglomerate
being thrown out in relief by the more rapid decay of
the soft slates with which they alternated. The dip was
everywhere very variable, and several very distinct sections
were displayed, where it was evident that the strata
were curved and sinuated. The curves observed were
convex below ; the strike of the strata was nearly perpendicular
to the general direction of the ravine, or from
north-west to south-east.
From Upshi, our course lay down the Indus valley in a
direction west of north. The width of the Indus, which
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