128 Notes, principally Geological, on Southern India. [Jan. 



felspar, and a litlle mica. The general outline of these fortified heights 

 resembles that of the rocks near Bellar}^ : vast blocks, both rounded and 

 angular, resting on a large convex plateau, and near the base forming 

 caverns. The height of the most elevated has been calcuhited at 800 

 feet above the plain. The general direction of the range is N. by E. 



Herrioor. — The bed of the Hogri here is of clay slate, into the compo- 

 sition of which, chlorite and a little mica, in minute darkish scales, enters ; 

 giving the rock a speckled appearance. Some varieties are compact, 

 hard, and of a fibrous structure; others secdle, earthy, and dull. Thin 

 fragments of the latter, held in a platinum forceps before the blow-pipe, 

 fuse partially, but with difficulty, on the edges into a greenish grey 

 enamel. The surface of the plain is undulating, and covered with frag- 

 ments of the subjacent schists 



Sera. — The country between Herrioor and Sera, is a succession of 

 plains, the principal rock of which is gneiss, crossed to the E. by dykes 

 of greenstone; beds of a hard mica slate occur, traversed by veins of 

 ferruginous quartz, and quartzy iron ore. 



Curbah. — From Sera, through Columbella and Chuloor, to the vicini- 

 ty of Curbah, the surface of the country is an undulating table land, gra- 

 dually rising towards Seringapatam — the formation much the same as 

 between Herrioor and Sera. 



Near Curbah, however, the principal rock appears to be of a white 

 quartz, with talc disseminated. The whole has a schistose structure, 

 common to many of the rocks in the vicinity of Seringapatam. A 

 brown variety, with mica in spangles, resembles avani urine. Com- 

 pact kanker and nodules of heematitic iron ore, are found here in beds, 

 near the surface. 



Belloor. — Approaching from Myasamudrum, the Mysore plain, or 

 table land, is diversified by two low broken ranges of hills, of a fine 

 grained grey granite, with small crystals of shining felspar. A coarse 

 sort of gneiss is found in the beds of nullahs in the plain, with largish 

 scales of silvery mica, and crossed by beds of talc slate with chlorite. 



Near Belloor, these hills subside into a rocky swell, on which rests 

 both masses of granite and gneiss. At Belloor, the lowest stratified 

 rock I observed (18 feet below the surface), was gneiss abounding with 

 small scales of glittering black mica. The strata were slightly inclin- 

 ed — dip west. Potstone, talc, and chlorite slate, associated with the 

 gneiss, are found in the neighbourhood. Direction of the hills nearly 

 due north. 



Nagamwigalum. — Plain — formation gneiss, with both white and pale | 

 red quartz. Dip of strata 41° to the westward. Direction north. 



