The valley of Nepal Proper, which contains Kathmandu, or, as many call it, Kathmaro, Lalita Patan, and Bhatgang, is the largest in the dominions of Gorkha, and in this plain there is not naturally a single stone of any considerable size. The whole, so far as man has penetrated, consists of what is called alluvial matter, covered by soil. In some places the alluvial matter consists of thick beds of fine gravel and sand, much of
which is micaceous. Among these beds are found concretions of the same materials, united into balls, about the size and shape of a turkey’s egg. At one end these are generally perforated with a small hole, and some, but not all of them, are hollow. The Newars call them Dungoda; but can give no account of their formation, nor did I observe any thing that could lead to an explanation.
A large proportion of the alluvial matter consists of a blackish substance resembling clay. It seems to approach nearer to the nature of turf than any thing with which I am acquainted, and I have no doubt is of vegetable origin. It is called Koncha by the Newars, who dig out large quantities, and apply it to their fields as a manure. The beds, in which it is disposed, are often very thick and extensive; and it is always much intermixed with leaves, bits of stick, fruits, and other vegetable exuviæ, the produce of plants, similar to those now growing on the neighbouring hills.
The various rivers that pass through the above-mentioned Koncha, have washed from its strata another harder and blacker substance, but still having so strong a resemblance, that it is called Ha Koncha. This is most commonly found in the channels of the rivers, and by the natives is supposed to be decayed charcoal; but the great size of some of the masses seems to me incompatible with the truth of this opinion.
A kind of blue martial earth, the earthy blue iron ore of mineralogists, by the Newars called Ong Shigulay, is also found commonly intermixed with the Koncha. It is never in large masses, and, in my opinion, has derived its origin from some vegetable substance that has been gradually impregnated with iron. Cones of the pine may be traced in all stages, from those retaining a half of their vegetable nature, to those
entirely converted into martial earth, and only distinguishable by their shape as having once been vegetable productions. The half-formed specimen that I procured is a cone of the Pinus strobus; but the more common ones are exuviæ of the Pinus longifolia.
In the alluvial matter of the plain of Nepal are also found large strata of clay, fit for the potter and brickmaker.
The greater part of the mountains which enclose the valley of Nepal consists of grey granite, of which the surface is very much decayed wherever it has been exposed to the air. On the south side of Chandangiri, about four miles west from Pharphing, is a very large stratum of fine white sand, which the Parbatiyas call Seta mati, or white earth. It seems to me to be nothing more than decayed granite; and I think it probable, that the sandstone found on Sambhu, and the neighbouring hill towards Hilchuck, is composed of this granitic sand reunited into rock. This sandstone is used in a few buildings, but I have seen no large blocks, and the difficulty, or impracticability, of procuring such, has probably occasioned this stone to be in general neglected.
The stone usually employed in Nepal for building is a rock containing much lime, which is so impregnated with other matters, that, though it effervesces strongly with acids, and falls to pieces in a sufficient quantity of these liquids, yet, by calcination, it cannot be reduced to quicklime fit for use. It is disposed in vertical strata, is very fine grained, has a silky lustre, cuts well, can be procured in large masses, and powerfully resists the action of the weather, so that it is an excellent material for building.
Limestone is so scarce, that clay is the only mortar used by the natives. We, however, visited a quarry on the mountain called Nag Arjun, where the people obtain lime for