Physical description of Sikkim mountains.
Travelling through Kinchin snows.
My dear Darwin
This is to be a continuation of my travels amongst the Snows of Kinchin junga, the first part of which, including my Nepal journey I detailed in a letter to Lyell, which he will forward to you:—this relates to Sikkim altogether.
I formerly sent you a little account of the general features of this region, & described Sikkim as a country wholly composed of meridional spurs from a Mt. 28170 ft. high. Of these, that forming the boundary of Nepal, runs nearly South from the great Mt: to the plains, as an almost uninterrupted ridge, no part of which for 50 miles descends below 10000 ft; & upon which many peaks attain 13,000 some 20,000 & one 25,000 ft.; the latter the most Northerly. Similar spurs of rather less elevation run E. of & parallel to this. Two great rivers drain the Snows of the S & E. faces of the great Mt. in Sikkim & unite near the plains, debouching as one on the latter, through a narrow gorge amongst the lofty outer range, & is there called the Teesta— Their channells are very deep & do not rise above 4000 ft till within a few miles of the Perp. Snow— Lateral spurs run parallel to one another, E & W from the great meridional ridges, & intersect the country every-where, they are lofty, averaging 6 & 8000 ft, sharp on the crest for miles, & so numerous that turn where you will “ridge & spur” are always the characters of the scenery.
Although the Europeans have selected a site at 7–8000 ft for their Sanatarium; the native villages hardly ever occur above 5000 & none I believe so high as 6000. Below 5000 ft they are very numerous & always occupy curious little flat topped terraces, which start abruptly at all elevations from the flanks of the valleys, & are not capable of accommodating more than 2 or 3 houses & the necessary room for the inhabitants to cultivate.
The valleys themselves are exceedingly steep, but rarely precipitous & densely clothed with forest up to 12000 ft. Though the ridges are often horizontal enough for many miles for habitations, they rarely have breadth enough. In E. Nepal the main features of the country are the same, but the mean elevation of the land is less, of the snowy range greatly so. The latter forms a much narrower belt, & it further trends a little to the N.W., so that there is full 80 or 90 miles of SubHimal. between the Plains of India & Perp. Snow in E. Nepal but only 60 in Sikkim— Hence a tropical vegetation advances good 20 miles further north in Nepal—in both cases following the sinuous course of the larger rivers, the beds of which descend very suddenly from the Perp. snows to 5000 ft. from which to the plains the stream is uniformly rapid, but seldom very violent, & never broken into waterfalls. Terraces are very frequent along their margins; however narrow the gorge they flow through; varying in length & breadth with the nature of the valley, & in height from 10 to 60 feet: or even 100 ft. These are formed of sand gravel & enormous water-worn masses of rock, their banks are precipitous, their tops, where cleared, seen to be covered with great blocks of stone: & where not, always supporting a rank jungle, with enormous trees. These are evidently the deposit of an incomparably greater body of water than ever now flows along the river channells, even the lower (I do not say the lowest) are never reached by the highest floods The great size of the timber & depth of humus shews that vegetation has long held undisputed possession of the flats. They are often occupied by villages; & in the only valley which I have seen to expand to the breadth of a mile or two, the whole floor was occupied by such a deposit.
These form the frequent, if not constant features of the river banks at all elevations below 5000 ft, & I regard them as the lowest (in a descending series) of the evidences I think I have obtained, of the waters occupying a much higher level than they do now, relatively to the land
A uniform deposit of red clay, of great tenacity, covers the whole country, up to 12000 ft; throughout the forest region in short; the vegetation retaining it on the lofty & sharp spurs, as well as on the steep flanks of the valleys. Where it comes from is not clear, but in the disproportionate amount of alumina it contains, it offers a parallel to the Gneiss rocks & more especially the Granites of this part of the Himal. in Feldspar is unusually abundant.
The depth of the clay upon the shelves where the villages are built, is often
great,—30 ft. & the rock underneath is always in fragments.
though I believe so far in situ, that the fractured state of the nucleus of the majority
of all the spurs & ridges is due to oscillations or Earthquaqes of the land for
the irregularity is of dip & distortion of all the rocks increases rapidly in
approaching & ascending the Snowy Mts.— Rock seldom crops out near the
shelfs, though I have seen such to be the case, the solid base supporting the clay.
Their edges are generally worn round & grassy where cleared— Streams
from the mts above flow rapidly down to & sluggishly along their tops. Sometimes
they present ponds on their flat surface, & this is the most remarkable of their
features; the ponds frequently having no outlet whatever, the water draining away
underneath These are always shallow, of clear water, their basin & margin both
of clay & great masses of rock are almost always strewed about their
banks— These are the only quiet waters in Sikkim; the largest, a very holy
place, to which I was conducted, occupied a large terrace, is good 300 yds
broad, of unknown, probably not great, depth. The elevation is under
7000 ft.—it is enclosed on nearly 3 sides by the sudden
slopes of ridges, whose tops are flat. on the rest by a slight raising of its own
The pencilling above may give a shadowy idea of the cut of the ridges. A the loftiest,
is 1000 ft above the Lake & bears a Bhothea temple (Catsuperri Goompa.)
B. is anoth spur & D a third respectively higher & lower than
C, which bears the lake. D has a large marsh, one side of which is walled by
D. just as one side of the Lake on C is walled by B. A section through
the arrow would run thus
I entered Sikkim towards the end of Decr
Except a great number of dips & an examination of some much better sections of mts & rocks than I had before seen there was little to be done in Geology, always barring seeing more & more of the village sites, shelves or terraces, as I call them, which strengthen the possibility of my guesses as to their origin.
I staid 3 days on the Teesta & enjoyed the time with Campbell keenly, his being the first white face I had seen for so long; the first person to whom I had talked English & familiarly too. He further kindly consented to accompany me for a few days, on my way back to the point from whence I had diverged from the route to Kinchin.
We ascended a mt of 12000 ft on this spur, & found the Snow (which had
been falling lately) at 7000 ft, a foretaste of what Kinchin was to be, from a
visit to which the natives now tried to dissuade. We encamped on the Snow the first
night & reached the top the following morning, taking up our quarters in a
deserted Buddhist temple. From this position we had a superb view of the Snowy range
& my first insight into the structure of elevations above 16000 ft. for
a grand peak, of about 20000 ft., presented a cliff of white Plutonic rocks
capped with a red & black mass of baked & distorted stratified do.
The weather was fortunately splendid & not being able to stir from the spot from deep snow & jungle I had a fine opport. for observing drawing & watching the varied & beautiful phenomena of the atmosphere, as they suceeded one another from one sunrise to the next, for the prospect included the whole of Sikkim from the Bhotan Snows to the Nipal frontier & from the Snowy Mts to the plains & its winding rivers. Having had comparative observations taken for me throughout my journeyings by an invaluable friend at Dorjeeling I hope these too will be of value.—
Thence we descended to the Gt. Rungeet, & visited the oldest convents of Sikkim, all Buddhist—& wonderfully beautiful as to internal decorations— these we measured drew & described, they are eminently curious, purely Buddhistical, without a trace of Hindoo worship. Another day took us to the Pemiongchi convents, also very remarkable for their size antiquity & paintings— Here Campbell left me for Dorjeeling & I proceeded to the Snows, with a party of about 25.— The last village (Yoksun) is at as low an elevation as 5000 ft & the most remarkable in site of any I have seen in Sikkim: it occupies too much the greatest extent of flat ground, though buried amongst the loftiest spurs I am sure it is a glacial deposit, & had I time to send you a birds eye view of its features & position relatively to a curving spur against which it abuts & whose hollow is opposite the (Ratong) valley, of the greatest river which descends from the P.S. of Kinchin, you would I think say so too.
I am now more than ever alive to the fact, that any flat in Sikkim ought to be an object of suspicion to the Geologist: & that for one that has resisted the 8 months rains of this region, there must be hundreds washed away. We ascended the Ratong valley slowly & with a good deal of labor for 3 days, reaching on the third much snow at 8000 ft—hence up through the forest to beyond its limits at 11000 ft—where we emerged on a lofty long spur from the shoulder of the Grt. Mt. The Perp. Snow on all sides at 14000, the great top N, about 8' off, & the two main shoulders one on each side with Peaks of 22 & 25000 on either hand. The Ratong between wound up to the granite cliffs of the central mass, flanked by the lofty precipices of which I send you a pencil outline above (as seen from 20 miles further off.) We floundered along through Snow & dwarf Rhododendrons to a spot at 13000 ft, where at Jongri are 2 stone huts, once used by the Salt traders, who many years ago took this route to Nepal & thence to Thibet, but only in the height of summer: the Gherkhas have long since closed the pass. It was by the latter that I had intended to have entered Sikkim from the Yalloong valley in Nepal.
Here 2 geolog. phenom. apparently of interest struck me. The spur I was on had an average elevation of say 13000 ft. & was covered with low mound like hills of 1000, these are deeply covered with shingle, which appears every where in landslips. The Jongri spur is further broad, rounded & hog-backed:—of the hundreds around none were like this, all others being jagged peaked & evidently the naked masses of strat. rocks carried up by the Kinchin granite. This has no doubt such a nucleus, but is thickly covered with detritus & great angular transported boulders of Granite & Strat. rocks strew the surface.. It is further covered with hundreds of little lake beds, which give a terraced form to parts, they occur over all the greater depressions of the top & upper flanks, all are dry & many have a bed of fine silt, no doubt deposited by the summer rains, but the summer rains can have nothing to do with their original formation, nor with the little curving ridge of rocks that is projected on to their beds, from the mouths of their effluents any more than they have with the great shingle deposit of the whole surface of the Jongri spur & out of which these are fashioned. The Snow, & ground frozen to 16 inches, prevented my examining them as I could have wished.— The arrangement of each is a miniature of thousands of similar ones at the inferior limit of the P.S. in these regions; it is only their quantity, their occurrence on a hog backed ridge, far from either glacier or bed of P.S. whose melting could reach here, that is so curious. Now the whole ridge runs obliquely across the great Ratong valley, & I do think it probable that the waters that deposited the detritus on the Lake beds at 11,–14000 ft in Yangma & the other Nepalese valleys, covered this with shingle & boulders & that the pools were formed by the retirement of the waters, these shew no signs of violent rushing of waters during the relative change of land & water— On the said Jongri spur on its S. slope or dip to the Ratong are at intervals of several 1000 ft. 3 successive lake beds, the lowest about 1000 ft above the bed of the Ratong. There is also on one part of the slope a most enormous mass of Gneiss, certainly not in situ Space & time prevent my alluding to hundred other little points
The upper Ratong valley, from 10000 ft. to its source below the top of Kinchin is, say, 8 miles. From Jongri spur you look right up it— It runs close under the precipitous E. shoulder of Kinchin. the precipices of the latter rise from enormous shingle banks, very steep & covered with great beds of Perp. Snow. The W. bank of the river is apparently more shelving & flanked with oceans of Perp. Snow at about 14000 ft.— At the base of the shelves on the E. flank are a sucession of spurs, of 2–500 ft high: all of shingle I should think there are others at various heights upon the shelves. These are the universal accompaniments of the glaciers & steep snow beds throughout the Himal. I have seen, but I had no where observed so great a sucession of them, for no where have I seen a river at this elevation hold so gentle a slope for this distance. The resemblance to the village spurs or shelves all along the flanks of the great valley at 2–6000 ft is remarkable, though here the edges are sharper— I now looked for lake-beds upon them, & soon saw several which were immediately overhung by snow beds, to have the whole surface depressed, so that I could not from the distance see the bottom, nor where the water escaped, supposing it did not filtrate through the debris. I have elsewhere been on many such forming spurs: they are generally frozen hard at the season I saw them, & consisted of shingle cemented with alumina from the Feldspar into half clay & half breccia— In Nepal they abut on & even overlie the great glacial deposits & in cases where the miniature modern deposit & ancient one have been swept from the same valley, you can see the one to follow in its often winding course all the features of the great. These spurs on the upper Ratong valley are often projected on to the floor of the valley, as independent structures, at other times there is on one side or other (or in centre) a nucleus of rock. I have seen masses of rock toppled on them, but never the transported boulders that strew the Lakebeds & Yangma ancient terraces.
With the Peak of Pundim I shall conclude this long weary yarn. it is one of those on the E shoulder of Kinchin, i.e. on the E. flank of the upper Ratong valley & rises from the Shingle beds to 22000 ft above the sea— In common with the other mts flanking that valley its W. front is a stupendous precipice— From 4 miles off (it is of course inaccessable) the lower part of the cliff presents the extraordinary appearance of shot or watered silk from the contortion of the Gneiss & other strat rocks, which are twisted & coiled together like snakes; they are red grey & black & broad white veins of Plutonic rock are shot through the mass in all directions, which latter rock of nearly a pure white caps the whole.—
I camped 3 days at 13000 ft when the heavy falls of Snow warned me to retire from this most interesting position. We had one days march through 4 feet of Snow but my people all Lepchas (for I had got rid of my unruly Bhothan men on entering Sikkim) behaved admirably— as we descended we soon got into less fatiguing ground & in about 10 days after I arrived in Dorjeeling.
As to dip I can give you very little information— I have taken very many; the great majority are NE & NW. The confusion & dislocation of the strata above 12000 ft is extreme. witness the isolated peaks capped with Strat. Below 12000 the forest is a great impediment to all observation. My impression is that much of the Quartz is Plutonic. I have seen broad veins through mica schist, against the strat. & emerging along with fragments of the mica schist, which was baked to excessive toughness all along the vein. There is much strat. Quartz besides. I have an impression that much of the Plutonic rock between the real granite & strat. is the latter fused & shot through its unfused neighbour— I think this has taken place to an immense extent, but have nothing to shew but mineral specimens. Mineralogy or Petrology is far too much neglected by Geologists, I would have given worlds for Henslows knowledge of the metamorphosis of mineral masses.. I am sure from the appearance of the garnets mica & Feldspar that many of these are derived from the gneiss fused & its constituents rechrystallized—I have seen little if any Hornblende augite or volcanic mineral whatever—at least I did not recognize them—no metals or chrystals or nice things for a cabinet.
I fear I have missed the Feby. steamer with this. Send it to Lyell & change with him— Sincere regards to Mrs Darwin & to the Wedgewoods & to Bell & all such old & dear friends you may see. Love to the childs
Ever yours affectionately Jos D Hooker
- f1 1219.f1Since Hooker's previous letter to CD (letter from J. D. Hooker, 13 October 1848) he had completed an expedition through the Sikkim Himalaya and Tibet, returning to Darjeeling on 19 January 1849. Hooker's published account of this journey makes up most of the first volume of J. D. Hooker 1854. Many of the details in this letter are further elaborated in chapters twelve to sixteen.
- f2 1219.f2‘The hill-station or Sanatarium of Dorjiling [Darjeeling] owes its origin … to the necessity that exists in India, of providing places where the health of Europeans may be recruited by a more temperate climate … Dorjiling ridge varies in height from 6500 to 7500 feet above the level of the sea; 8000 feet being the elevation at which the mean temperature most nearly coincides with that of London, viz., 50o’ (J. D. Hooker 1854, 1: 115).
- f3 1219.f3See Campbell 1849, p. 525, for Andrew Campbell's account of the meeting with the Sikkim Rajah.
- f4 1219.f4C. J. Muller (see letter from J. D. Hooker, 13 October 1848, n. 8).
- f5 1219.f5John Stevens Henslow had held the chair of mineralogy at Cambridge University, 1822–7, before becoming professor of botany.