138 Notes, principally Geological c?) SouthenL India. [Jam. 



quartz. A niRgnetic iron sanrl is found in some spots on the road in 

 the vicinity of the trap dykes, which has prob:ibly resulted from tlieir 

 decomposition. Most of the basaltic greenstone found here slightly 

 affects the magnet, 



Palsamudrum. — From the Mysore frontier to Palsamudrum, the for- 

 mation is thick bedded, or granitoidal gneiss, in highly inclined strata. 

 Masses of granite occur detached, precipitated apparently from the 

 peaks in the vicinity. The gneiss is intersected by basaltic greenstone 

 dykes, running generally in an easterly direction, from the Polla range 

 on the right, across the plain, towards some outliers of the Nundidroog 

 chain on the left or Avest. A few of these dykes take a north and 

 south direction, but nppear to be ramifications of the former. Veins 

 of actynoUte slate, generally flanked by pegmatitic beds of a red fel- 

 spar, Mith a transparent quartz, traverse the gneiss in the neighbour- 

 hood of the greenstone dykes, Vtith whose direction they in a great 

 measure conform. Ranker is seen in compact nodules, both of a grey 

 and reddish colour, on the banks of the nullah; and, though rarely, 

 forming small mammillary mounds, apparently around the mouths of 

 the extinct or dried up springs by which they probably have been de- 

 posited. A few miles south of Palsamudrum, flanking the greenstone, 

 I observed some angular blo;ks of sienitic granite, consisting of an 

 opaque feUpar imbedding crystals of schorl, with a little grey quartz. 



The basaltic greenstone in every way resembles that of Baugoopilly. 

 The augite crystals on the surface decay into a reddish white earth, 

 which, falling out, leaves the cavities observable on the surface. Crys- 

 tals of felspar imbedded in it are subject to similar decay, leaving larger 

 cavities. Magnetic iron ore, in crystals, is found in most of the rocks 

 of this place. 



Terimany.—'Fi'ova Palsamudrum towards Jaulipet*, the road lies prin- 

 cipally through a valley betv»'een two short ranges, apparently of gneiss 

 and granite, which run in a north and south direction. The valleys or 

 breaks form acute angles with the line of direction. The hills are rocky 

 masses, covered with their own exfoliated fragments, and destitute of 

 vegetation, save a few bashes principally of cacti, euphorbia, and mi- 

 mosa. Emerging from the valley alittle south of Jaulipett, the indented 

 outline of a long range to the west, pursuing a parallel course to those 

 on the east, appears on our left, at a considerable distftnce. Spurs from 

 both ranges are thrown across the plain, and form partial barriers. 

 North of Jaulipett, the eastern range terminates in the rock of Pen- 

 naconda, about a koss and a half from Goghirry^ A few detached out- 

 liers continue nearly to Terimany. The v/estern range still bounds 

 the horizon to the left, preserving a deeply indented outhne. The gaps 

 in both the ranges seem to have a parallel direction. Indications of 



