TRAVERSES IN NEPAL

J. B. AUDEN

Against the thousands who suffered from the Bihar-Nepal earth- quake of the 15th January 1934 may be counted the few who were able to arrive later in safety after the catastrophe and examine its effects. I was one of a party of four, from the Geological Survey of India, including Mr. D. N. Wadia, Dr. J. A. Dunn, and Mr. A. M_% N. Ghosh, which was sent to examine the effects of the earthquake.

Through the kindness of His Highness the Maharaja of Nepal, it was possible for me to make three traverses in Nepal to carry out a study of the earthquake there. The first of the traverses was to Katmandu, whence permission was given to visit the chief towns in the Nepal valley and to make two short excursions to the Trisuli Ganga and the Indrawati rivers (Survey of India degree sheet 72 E). The second traverse was from Jaynagar to Sirha and Udaipur Garhi (map 72J). The last and longest traverse was from Jogbani to Dharan, Dhankuta, Ghainpur, over the Milke pass to Taplejung, and thence over the Singalila ridge to Darjeeling (maps 72M, N, 78A).

It is difficult to know how many Europeans have visited eastern Nepal, but, so far as I know, I may have been the first to have been to Udaipur Garhi, and also past Ghainpur over the Milke pass to Taplejung. In 1848 Sir Joseph Hooker had traversed the Tamur river over routes which crossed mine in one place, and almost coincided in others.

These journeys of mine were made in February, March, and April 1934, during months when visibility was very bad. The snows were seldom seen from Katmandu and Udaipur Garhi, and were never visible at all during the last traverse along the Arun and Tamur rivers. During the last traverse, visibility was so poor that it was often impossible to see more than a distance of five miles. Photography was impossible. From the point of view, therefore, of obtaining new aspects of the southern slopes of the main Himalayan range, the journeys were an almost total failure.

Maps.

The four miles to one inch (1: 253,440) maps of Nepal which have resulted from the recent survey carried out by the Survey of India are, in general, excellent. It is not to be expected that every small ridge and every contour line is accurate. This survey of some 50,000 square miles, or 129,500 square kilometres, was carried out in a short space of time (Nov. 1924-Mar. 1927) and without European supervision. The broad and even the lesser details are, however, all well shown and are a striking tribute to the thoroughness with which the Indian surveyors carried out their work.¹

Nepal valley (map 72E).

After leaving Raxaul sixteen miles of fields and eight miles of sal forest bring one to the foot of the Siwalik hills. The next thirteen miles are through Siwalik hills with scenery familiar to those who have crossed them near Dehra Dun. Turreted hills of conglomerates border both sides of the Churia pass (approx. 2,200 feet), which is tunnelled for about 300 yards. After Sanotar pre-Tertiary rocks are encountered, and the scenery becomes typical of the slate zone (predominating slates, with quartzites and limestones, here mostly metamorphosed) of the outer Himalaya eastwards of Simla. The road ends at Bhimphedi, where the Maharaja had sent a pony and two servants to meet me. The second of the two passes between Bhimphedi and Katmandu (Chandragiri pass, 7,400 feet) is on the rim of the Nepal valley. The white palaces could be seen 3,000 feet below in the distant haze, with fields fading out beyond. It is small wonder that this valley has been a centre of civilization since before even Asoka had consecrated it with his stupas.

As noticed by Medlicott in 1875, there are considerable analogies between the Nepal and Kashmir valleys. Each is surrounded by a ring of hills, and each has been partially filled by fluviatile sediments. Lakes still exist in the Kashmir basin, and the alluvial deposits there are not sharply dissected. In the Nepal valley the once continuous sheet of deposits has been cut into by local streams joining to form the Bagmati river, many of which flow in broad channels as much as 170 feet below the general level.

I saw the Nepal yalley at a time of heavy cloud and rainfall, when the distant peaks were seldom visible. Possibly this biased me, but scenically the Kashmir valley with its close ranges of snow peaks, its lakes and trees, appears to be the more beautiful of the two. The attraction of the Nepal valley is largely in its people and architecture. There can be few more impressive sights than the temple of Swayarnbhunath poised on a hill overlooking the valley, its golden roof fusing in the setting sun. The brick-panelled temples and houses have a charm the more sensible for its absence in the generally featureless character of many Indian cities, where artistic talent has tended to confine itself to a riot of balustrades, pinnacles, and plaster ornamentation.

' The broad features of relief and drainage of eastern Nepal are shown on the map that I have drawn to accompany my note which follows Mr. Auden's paper. I lie places referred to by him have been indicated.—Ed.

The track to the Gurkha district leads over the Sheopuri Lekh. From Kaulia, 7,051 feet, Hermann de Schlagintweit in 1855 mistook Gauri Sankar for Everest. Gaptain Wood visited Kaulia in 1903, and was able to show that Everest and Gauri Sankar were different peaks. At dawn in February I had a splendid view of the main range from Kakani bungalow, close to Kaulia. Mount Everest was probably visible as an insignificant peak at a bearing of 84°. The chief peaks were Gauri Sankar (82°), Gosainthan (51⁰), the 24,300 and 23,400 group (346°), and the 26,660, 25,700 group (317!⁰).¹ The photograph shows the latter two groups, and was taken towards 331 The length of range seen was about 160 miles.

The foot-hills themselves are for the most part covered with cultivation terraces, and resemble those farther to the north-west, in Kumaun and Garhwal.

Udaipur Garhi (26° 55': 86° 32', map 72J).

For my second traverse, an elephant met me at Jaynagar, and, after calling on the Chhota Hakim of Sirha, I went on direct towards the hills. Camp was pitched at Nipania, which proved to be the epicentre of the earthquake as determined by comparing the Kew and Bombay seismograms. Field evidence, however, indicates that the epicentral tract was farther to the south-west, in Bihar. After another six miles we entered the Siwalik hills, passing lakes that had been formed as a result of landslips set off by the earthquake, and finally crossing the ridge of conglomerates called the Mahamanda Danda. Udaipur Garhi stands on an outcrop of Lower Siwalik or Nahan sandstone which underlies the main boundary thrust. In few places can this great Himalayan tide, which has brought forward the pre-Tertiary rocks so as to overlie the Tertiaries, be more manifest. It is the same as one sees looking west from the Dehra Dun-Mussoorie road above the power-house, or better, looking east from the hills just west of the Tons-Jumna confluence. A fairly accurate parallel is the view from the Scharfberg in Austria, from which the nappe of the Hollengebirge is seen to override the gentler flysch country.

Mount Everest is not visible from Udaipur Garhi, the conspicuous peak being Numbur (22,817 feet) which is taken locally to be Everest. The dominant feature is the Mahabharat Lekh rising to 8,000 feet. From an off-shoot from the Mahabharat Lekh, 3.3 miles ENE. of Udaipur, Mount Everest is just discernible 73 miles distant at a bearing of 17Numbur peak lies due north at 53 miles, and Gauri Sankar (23,440 feet), 70 miles distant, at 348°. Only the upper part of the south face of Mount Everest is visible from here, the lower portion being cut off by the main Mahabharat Lekh. A fuller view would be obtained from the Lekh itself, but time was limited and the traverse was not primarily intended for observations of peaks.

Arun and Tamur rivers (maps 62M, N).

My third traverse began at Jogbani railhead, four miles from the large district head-quarters of Biratnagar. The Bara Hakim provided me with an elephant and bullock carts. There followed long hours shifting to fit the movable contours of the elephant's back and listening to its bell. The west wind blew continuously, lifting the finer sand from the earthquake vents till one's mouth gritted up and fury gathered like a sore. The bullock carts that day took 17 hours to do 20 miles and arrived at 22.00 hours. That night part of Pakari village caught fire. By the morning it was gutted, and dogs and vultures were eating the half-roasted flesh of goats that had been burned alive. We left the rubbish and soon passed through sal forest until Dharan was reached. There appears to be no Siwalik range here, since the Gangetic alluvium occurs northwards so as to abut on to pre-Tertiary rocks.

The route northwards passed over a quartzite ridge, called the Mahabharat Lekh on map 72N. Dhankuta is situated at 4,000 feet at the southern end of the great north-south ridge separating the Arun and Tamur valleys.¹ It is comparable in scenery and geology to Ranikhet. There is little to record of the trek over the Buranse Danda, down to the Arun river, to Legua Ghat, along the Pilua Khola, up to Chainpur, and over the Milke pass to Dumuhan, the Tamur river, and Taplejung. Hooker must have passed through Dumuhan on his way to Walungchung and Yangma, some thirty miles to the north. Part of the Tamur valley is well shown opposite page 196 of vol. i of his Himalayan Journals, the view-point being Ghhintang village (27⁰ 18':87° 40', map 72M). Hooker went through in November and December, when the air must be clear and invigorating. There is little to recommend these deep valleys in March and April. The haze and dust were frequently so dense that it was difficult to see across the local valleys. The snows were never seen. From Taplejung my route was across the Kabeli river to Angbung, and thence to Yektin, Memeng, over the Singalila ridge between Sandakphu and Phalut, and on to Silikhola, Rimbeck, Phedi, and Darjeeling. This appears to be the chief route into Nepal from the east, one used by Gurkha soldiers and Darjeeling servants when going on leave to their homes. On map 72M the main path is shown leading from Memeng up the 9,386-foot ridge to Phalut. The more usual one, however, goes south of this over Sabargam (11,641 feet).

 

Ranges.

Geographically, Nepal and the eastern Himalaya may be divided into five units:

The Siwalik ranges are probably the only ranges in which geological strike and geographical extension properly coincide. Their width in Nepal across the strike is from 12 to 13 miles.

The Mahabharat Lekh consists of ranges adjacent and roughly parallel to the Siwaliks and composed of a varied assemblage of rocks with strikes less constant than is the case with the Siwaliks. It is a marked feature in the south-east quadrant of map 72E, north of Udaipur in 72J and to a lesser extent in 72N. Sir Sidney Burrard¹ has discussed the relationships of the lesser Himalayan ranges, leaving it an unsolved question as to whether or not the Mahabharat Lekh is a continuation of the Mussoorie range.

The only definite structural feature which is known to follow through the greater part of the Himalaya is the main boundary fault, a thrust which, east of about longitude 78°, separates pre- Tertiaries from underlying Tertiaries. It is certain, however, that the units separated by this thrust are not everywhere geologically and geographically analogous. The geology of the lesser Himalaya is so complicated that more than one geographical feature may be represented by a single major tectonic unit. The converse also holds. Moreover, the geological and tectonic units are not all persistent, a case in point being the dying out of the Dagshai and Kasauli rocks, so characteristic of the Simla hills, near the Jumna river. Burrard has suggested (loc. cit., p. 99) that the Kasauli ridge and the Mus- soorie range are analogous, presumably because both overlook the plains. In reality, the Mussoorie range is the south-east continuation of the rocks of Krol hill, which lies near Solon, between Kasauli and Simla, and the Kasauli ridge is unrepresented at Mussoorie.¹ The Krol range itself appears to die out as a marked feature to the northwest, at approximately lat. 31⁰: long. 77⁰. To the south-east it passes through Mussoorie, Garhwal, and probably continues to Naini Tal. There is a complication, however, in the possibility that at Lans- downe there may be an outlier of a higher tectonic unit on the Krol rocks not found either to the north-west or south-east.²

 

South-east of Naini Tal it is probable that the Krol-Mussoorie range dies out, as it did to the north-west, as a significant geographical feature. The rocks at Udaipur, which may be equivalent to those of the Krol series, are a highly attenuated series of slates and dark limestones, separated from the overlying Darjeeling gneiss of the Mahabharat Lekh by a thrust, and having no influence on the scenery. The important feature at Udaipur is the Mahabharat Lekh. In the Darjeeling area the rocks equivalent to the Krol series are the Gondwanas which crop out at Tindharia and which again have no influence on the scenery. It is possible that the Mahabharat Lekh is the continuation of the Nag Tibba range. Burrard, however, has drawn in Fig. 1, Chart xvi, a lesser Himalayan range striking due west from Dhaulagiri and continuing towards the Peninsula as far as the Siwaliks.³ If this be a true range, it would be impossible to correlate Nag Tibba with the Mahabharat Lekh, since these lie one on each side of and are separated by this lesser Himalayan range of Burrard. There are other difficulties as well. Nag Tibba lies at the south-west end of the great ridge which descends from Bandarpunch peak (map 53J/nw.) and cuts across Tehri Garhwal. It belongs therefore to the fourth unit enumerated above. On the other hand, the Mahabharat Lekh in 72N is distinct from the great ridge which runs NNE.-SSW. between the Arun and Tamur rivers (72M).

 

The problem is too difficult to discuss in a short note. It raises questions as to the extent to which geological structure influences geographical features. It also necessitates an attempt to define the term 'range'.

In conclusion, I should like to thank His Highness the Maharaja and Prime Minister of Nepal for the facilities so liberally granted me in making these traverses.

 

LITERATURE

Hooker: Himalayan Journals, 2 vols., 1854.

Medlicott: Records Geol. Surv. Ind., vol. viii, 1875. Geological traverse in region of Katmandu.

Landon: Nepal, 2 vols. London, 1928.

Burrard and Hayden: A Sketch of the Geography and Geology of the Himalaya Mountains and Tibet (2nd ed., 1934, revised by Burrard and Heron). For a preliminary account of the Bihar-Nepal Earthquake of the 15th January 1934, with photographs and isoseismal maps, see Records Geol. Surv. Ind., vol. lxviii, pt. 2, 1934.

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