Near Chini, the mica slate contains occasional small crystals of cyanite, and sometimes passes into chlorite slate.

A short distance from Chini, the whole hill side has slipped down into the Sutledge, from the action of frost and snow, and the cliff now towers up from the banks of the river, presenting a sheer and perpendicular wall of between six and seven thousand feet in height. This vast mass is composed throughout of gneiss, and the road, which is a mere scaffolding, passes along the face of it, at 4,000 feet above the Sutledge, which is seen foaming below.

From this to the village of Leepee, the formation is pretty nearly the same, consisting of granite, gneiss, hornblende, mica, and quartz.

The granite about Punggee, Rarung, and Junggee, contains a large proportion of hornblende, and at Rarung it is also seen to assume a brick red colour, often traversed with veins of quartz, both red, amber, and white. The red granite appears only in masses imbedded in a yellowish variety, which is the true rock, and which towards Leepee gives place to gneiss and mica slate. Above the last mentioned rock commences the first bed of argillaceous slates, which continues interstratified with greywacke schists to the top of Roonung Pass. The alternations of these strata are frequent, sometimes the one and sometimes the other rock prevailing in thickness.

These beds are evidently the first indication of the transition, or lowest secondary formation of geologists, and extending across or through the Roonung Pass, downwards to Soongnum, they are seen to support strata of compact greywacke, and beds of quartzose rock, apparently analogous to and holding the place of the old red sandstone of Europe.

The town of Soongnum stands in a valley immediately between the Roonung Pass in its front and the Hungrung Pass in its rear. In front, the range of hills which form the right side of the Rushkoolung valley are composed of an argillaceous series, consisting of clay stones and greywacke slates, of different textures and degrees of induration, and dipping to the S.W. The strata in the rear of the town, forming the left bank, dip, on the contrary, to the N. E. and are composed of greywacke slates, compact greywacke, old red sandstone, and a superior stratum of limestone and greywacke. These towards the summit of the range gradually change their dip, and rise up again to the S. W., the whole being surmounted by a bed of dark blue secondary limestone, containing portions of clay and silex. This formation extends along both sides of the Rushkoolung valley, even to the Manerung Pass above Manes in Spiti, a distance of about seventeen miles. About seven miles from Soongnum, copper veins occur in their strata of white quartz rock, and veinous quartz, lying occasionally between, or ramifying through, the greywacke and old red sandstone. The

last mentioned rock varies much in colour and in texture, the lowest stratum being white, and scarcely distinguishable from quartz rock, but changing gradually to a faint tinge of pink, becoming deeper as it passes upwards, until its colour is of a dull purplish hue.

These strata are sometimes separated by a very thin layer of soft whitish marl. The crest of the Hungrung Pass is 14,837 feet above the level of the sea, and is composed of dark blue limestone. The range on which this Pass is situated divides Kunawur from Hungrung,-a district inhabited by Tartars, who are subject to Bussaher.

Descending from the Pass to the village of Hungo, the road passes over numerous alternations of blue limestone and greywacke slates, resting upon white quartz, which lower down gradually passes into a greenish variety of the same rock.

These strata all dip to the S.W., and are probably an outcrop of those which run in a N.E. direction from behind Soongnum, and thus shew the effects of what may be termed a double upheavement, or lifting of the same strata at two different points. The lofty granitic peaks which tower up to the right of the Pass, at once shew that they have been instrumental in forming the S.W. dip, and it is more than probable that the same rock might be discovered also protruding through the strata on the opposite

exposure.

The following partly imaginary section of Hungrung, may serve to explain my meaning:

(See plate)-FIG. 3.

Supposed Section of Hungrung Mountain.

Strata of greywacke slates are met with for a few miles after leaving Hungo; but they disappear as we approach Leeo, or rather, from the great descent of the road, they are left far above, while the base of the mountain is found to be a dark coloured gneiss, traversed and intersected in every direction by veins of white quartz.

Leeo stands in a kind of basin, surrounded on all sides by lofty hills of granite and the same dark gneiss; but the lower parts of them are overlaid by strata of the secondary series, consisting chiefly of greywacke and shales. On the sides of the surrounding hills exist strong indications of the former presence of a lake, in the lines of water-worn stones and pebbles that now rest many hundred feet above the river Lee.

These appearances were long since pointed out by Dr. Gerard, who though knowing nothing of geology, was at once forcibly struck with

1.1. Greywacke State.. 2. Compact Greywache. 3. Old Red sandstone. 4. Strata of Greywacke and limestone 5.5. Blue Limestone..

Strata of lamestone and Greywacke. 7. Quartz Rock while and Green

the conviction, that nothing but the former presence of deep waters could account for the phenomena here so plainly exposed to view.

In his conjectures on this head, that enterprising and unwearying traveller was undoubtedly correct.

In the bed of the Lee, where it is crossed by a wooden sangho, a thick bed of white quartz rock is seen dipping to the S.W., and as we mount the hill in the direction of Chungo, beds of boulders, and disjointed masses of granite, gneiss, and mica slates hurled from above, are passed over, now in many places overlying the secondary shales.

At the village of Chungo, which is the last on the left bank of the Lee, under the government of Bussaher, the most decided indications of the former presence of a deep lake again occur. To the eastward of the level patch on which the village and its cultivation stands, rise three lofty and rugged mountains, whose shattered sides present sections of the same strata as those noticed at Leeo: namely, deep beds of dark gneiss and mica slates intersected by granitic and quartz veins of various thickness; these strata dip down towards the west, and as they approach the village, are lost beneath the vast accumulations of alluvial soils, which here, as at Leeo, mark the former presence of deep and tranquil waters.

To the southward these deposits consist almost entirely of thick beds of clays, sands, and boulders of every size, rising high above the level of the village; while to the NNE. are again presented the same alluvial deposits of a greater thickness, and accompanied in addition by a deep and extensive bed of a pure white and friable gypsum. This bed is perhaps a most valuable discovery in a geological point of view, as tending to show the nature of the waters from which it was precipitated. This thick gypseous bed is overlaid by the sands, clays, and boulders, which have already been noticed. At the fort of Skialkur, on the opposite or right bank of the river, about 3 miles from the village of Chungo, this gypsum is likewise seen overlying the transition series of alternating shales and sandstones.

These deposits are now at the height of 2,000 to 2,500 feet above the present level of the river's course, or at an elevation of 12,000 to 12,500 feet above the level of the sea.

The three mountain peaks of gneiss, which rise up to the eastward of Chungo, are divided from each other by narrow glens, through which streams flow down to join the sea, between which and the base of these mountains, the whole alluvial deposits have been swept away, and the present cultivated plain of Chungo is therefore situated far below the surrounding alluvium, which rises like walls on either side of it.

As we proceed from Chungo towards Spiti, the road lies at first over the alluvial accumulations above-mentioned, for two or three miles, when from