During the post-monsoon season of 1970, the British Karst Research Expedition to the Himalaya pursued a programme of exploration and research in some contrasting areas of Himalayan karst. Though the Himalayan ranges consist dominantly of metapelites, there are important blocks of limestone, some forming the highest mountains in the world, but there is a rather disappointing lack of spectacular cave development. Now that most of the karst regions have been visited at least briefly by cavers, it is perhaps appropriate to review the situation.
At the extreme western limit of the Himalaya, the impure limestones around the Band-i-Amir Valley in Afghanistan appear to be essentially non-cavernous. Further south, in Pakistan, the Sulaiman ranges consist of topographically impressive limestones which have not yet been searched for caves.
The far north of Pakistan includes two interesting cave areas. The village of Chitral is surrounded by high limestone plateaux, and there are various unproven reports of caves in the region. Further east, Nanga Parbat claims fame for the highest known cave in the world. Only short, about 240 ft. long, the isolated Rakhiot Cave lies at an altitude of 21,800 ft.
Just over the border into India, the Vale of Kashmir is surrounded by limestones, unfortunately mostly dolomitic. At the eastern end of the Vale, near the town of Anantnag, are five major karst springs rising from the foot of the limestone hills. Some hydrological tests carried out by our expedition suggested the existence of large-scale stream caves, indicated by the very fast flow-through times, but access could not be gained. The only known cave in the area is the Bhamajo Bat Cave, just north of Bawan; this consists of 500 ft. of dry fossil cave passage.
A few miles north of the Vale are further outcrops of the same limestone at much higher altitudes, and these, too, were examined by our expedition. No significant caves exist, and the largest, the holy cave at Amarnath, is only a 50 ft. diameter chamber with no associated cave passages.
The caves and potholes around Simla and Chakrata were first investigated many years ago by migrant English cavers, and the results have been reviewed by Craven (1969). The regions near Simla were further investigated in 1970 by a second British party—the British Speleological Expedition to the Himalaya. However, only a few caves were found (pers. comm.); the longest contained about 300 ft. of passage, but some of them were very well decorated with stalactites.
KARST LOCATIONS IN THE HIMALAYA
The entrance of AmArnath cave in Kashmir
A line of gours down the main passage of Gupteswary cave, Nepal, with the Conglomerate Wallrock Clearly visible
Photo: Roger Browser
The South face of Daulagiri I, as seen from white peak
Photo: Roger Browser
The grand Barrier viewed looking up the Mristi khola
Not surprisingly, Nepal contains the world's highest limestone, and consequently became the main objective of our expedition. The Kali Gandaki valley at Tukche is crossed by the outcrops of the Niigiri Limestone, which rises over 16,000 ft. nearly to the summit of Dhaulagiri, and forms a massive slab to the very crest of Annapurna. But the limestone there is very impure, and, though some karst underground drainage does exist, it is essentially non-cavernous. There is, however, one cave near Tukche— the Kursangmo Cave on the lower flanks of Dhaulagiri which consists of a short, active and very beautiful streamway formed m a ihick layer of tufa, overlying the boulder clay.
In complete contrast, the Pokhara valley is floored by a series of young soft limestones. Only just south of the city, our expedition explored and mapped (see expedition report) the 4,800 ft. of passage in the Harpan River Cave. The river flows down an impressive shaft 150 ft. deep and into a large river passage, to reappear at the foot of a gorge half a mile away. The gorge itself is a huge collapsed cavern, formed where the thin conglomerate roof has broken down into a series of passages eroded in the underlying limestone. At present the cave system consists of a succession of abandoned river passages, now containing varieties of sediments, pools of standing water and a few stalactites. Our expedition discovered a total of six entrances leading into the Harpan River Cave, the easiest being in a large collapse doline surrounded by rice paddies only a hundred yards from the main road. Another distinctive feature of the cave is the enormous number of bats, large and small, which live in two large chambers at the entrances opening into the collapse gorge. The bat chambers are probably the only parts of the cave which do not fill to the roof with torrents of rushing water in the monsoon seasons.
Undoubtedly many further miles of cave await exploration beneath the Pokhara valley. Most will contain, or be associated wilh. large rivers and all will be subject to violent flooding. However none of the caves here will be deep, as these Pleistocene Inn .tones are only exposed over a relief of about 200 feet.
Some miles west of Pokhara, the village of Kusma lies on a high terrace overlooking the lower reaches of the Kali Gandaki viiIK v Opening in the side of the terrace and almost below the village is the cave of Gupteswary. A tall narrow passage, with a stream flowing out of it, may be followed some 600 ft. back into a series of chambers. The whole of the cave is beautifully decorated by profusions of active stalactites, flowstone banks and calcite gourpools ; in the largest of the chambers is a 20 ft. high stalagmite regarded as holy by the Hindus who visit the cave on pilgrimage. However, the most remarkable thing about the cave is that it is formed entirely in conglomerate, with a very low calcite content considering that the cave passages were at least initiated by solutional erosion.
The famous Yellow Band on Mount Everest is the highest limestone in the world, but its geological characteristics suggest that it could not support karst features. Indeed the known geology of all Nepal's very high limestone outcrops provide little promise of potential cave development.
South of Mount Everest, in the Sun Kosi valley is the Halesi Cave. Again a religious centre, this consists of a number of large dry chambers almost in the crest of a low ridge, but details of this fossil system are lacking.
It is difficult to delimit the eastern end of the Himalaya, particularly in the context of cave development. This is because the geological structures do continue into the spectacular karst regions of Burma, though the Brahmaputra River provides a major topographic break. Perhaps this brief survey should end with the caves of Assam ; large stream caves have been known for many years near Siju and Shillong (Craven, 1969) and these areas appear to have considerable potential for further discoveries of large but shallow caves.
At present the longest explored cave in the Himalaya is the Harpan River Cave in Nepal, but with modern improvements in travel, it is unlikely that this record will hold for long. Only the Chitral area of Pakistan appears to offer scope for deep caves, though it seems that the scale of caves in the Himalaya will never reach a grandeur appropriate to that of the mountains.
[The next article is reprinted from the above publication.]