Page:Madras Journal of Literature and Science, series 1, volume 6 (1837).djvu/375

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1837.]
Geology of the Deccan.
349

Those of a fissure-like character might have resulted from the upheaving of the beds of trap from below the sea, and the consequent probable fracture of the surface; but the same explanation will not apply to those valleys associated with the preceding, broad, flat, and margined by scarped mountains, which valleys are as wide at their origin at the crest of the ghats, and at the sources of the rivers which run through them, as in any part of their length.


Terraces.—As the rise from the Konkun to the Dukhun is by terraces, so the declination of the country eastward from the ghats is by terraces; but these occur at much longer intervals, are much lower, particularly in the eastern parts, and escape the eye of the casual observer. In the neighbourhood of Munchur, on the Goreh river, there are five terraces rising above each other from the east to the west, so distinctly marked, that the parallelism of their planes, to each other and to the horizon, gives them the appearance of being artificial. An artificial character also pervades the form of many insulated hills: some of which viewed laterally, appear to have an extensive table-land on the summit, but seen endways look like truncated cones. Conoidal frustra in the Gawelghur range have been already noticed. Other insulated hills are triangular in their superficial planes, as the forts of Teekoneh (three-cornered) and Loghur.


Escarpments.—Stupendous escarpments are occasionally met with in the ghats. In these instances the numerous strata, instead of being arranged in steps, form a continuous wall. At the Ahopeh pass, at the source of the Goreh river, the wall or scarp is fully one thousand and five hundred feet high;[1] indeed, on the north-west face of the hill fort of Hurreechundurghur, the escarpment can scarcely be less than double that height. On the other hand, the steps are sometimes effaced, and a hill has a rapid slope. This originates in a succession of beds of the softer amygdaloids, without any basaltic interstratification; their superior angles disintegrate, and a slope results. But most usually three or four beds of amygdaloid are found between two strata of compact basalt; the former disintegrates, leaving a slope, which is not unfrequently covered with forest trees, forming a picturesque belt: the basaltic scarp remains entire, or it may be partially buried by the debris

  1. Plate 9, fig 1.