946 Notes, principally Geological, from [No. 130. 



the beds of laterite being once probably continuous over its surface. 

 The trap is seen in the vallies and nullahs at their base, on which the 

 lateritic rock rests in tabular, horizontal masses. A siliceous porphyri- 

 tic rock, having cavities lined with minute brown crystals, is associated 

 with this rock, and is found in loose blocks on the surface. The imbed- 

 ding paste is a light coloured highly indurated jaspideous clay. Before 

 the blowpipe per se, the crystals lose their colouring matter, but fuse 

 with carbonate of soda into a white enamel. 



Went about two and a half miles to the east of Bagwari, to see the 



quarries whence the compact blackish trap is dug, 

 Quarries of Bagwari. 



used in building the walls of that town ; found the 



quarry to be nothing more than a large assemblage of basalt en boules, 

 lying partly on, and partly imbedded in, the soil covering a long swell, 

 probably a basaltic dyke, through the surrounding trap. I searched in 

 vain for an excavation affording a section of the intrusion of the former. 

 The basalt is different in mineral structure from that seen passing 

 through the granite, gneiss, and slate of the Ceded Districts, the 

 Nizam's dominions, Mysore, Malabar, and Canara. It is now amygda- 

 loidal and vesicular, and contains small globules of calcareous spar, 

 zeolites, and calcedony. The vesicles, however, are more usually empty : 

 some of them contain a brownish yellow earth into which I have ob- 

 served the zeolite to decay, and also calcareous spar, coloured with 

 the peroxidation of iron, which exists plentifully as the black pro- 

 toxide and carbonate. The fracture is conchoidal, fragments faintly 

 translucent at the edges ; streak, greyish white ; melts before the blow- 

 pipe into an intense green glass. It contains little amphibole, and 

 appears to be composed almost entirely of augite and felspar. 



The lateritic rock in the vicinity of Hori Math appears, generally, 

 Lateritic rock of Hori to co^ain more iron than the rock of Malabar 

 Matt - and Canara, and is consequently of greater speci- 



fic gravity. The specimens I obtained did not contain lithomargic earth, 

 nor so much quartz as the latter ; the tubular sinuosities are frequently 

 lined, like those of the Malabar variety, with an ochreous earth arising 

 from the decomposition of quartz and felspar, and tinged of various 

 shades of brown and yellow by the oxide of iron ; this earth forms 

 a compact paste, cementing more firmly the component parts of the rock 

 together : it exactly resembles in this respect, portions of the Malabar 



