MYSORE PROVINCE, SOUTHERN INDIA. 643 



cent., and the outer layer of the same stone, which was highly 

 weathered, was found to contain only 2"37 per cent, of lime *. 



Quartz-outcrops as well as detached pieces of all sizes arc plentiful 

 at the east end of the Section ; but a critical examination of most of 

 the outcrops led to disappointment, as the majority of them were 

 found not continuous when examined below the surface. About 

 one outcrop in ten proved, after exploration, to represent a true 

 quartz-vein of strength and permanence. Many of the outcrops arc 

 large at the surface, but when intersected 15 to 20 feet below, they 

 are found to diminish in thickness and in some cases disappear 

 altogether (fig. 8). 



Fig. 8. —Section showing dowmuard attenuation of Quartz-vein. 



a. Quartz. <!'. Schistose rook. 



Upon an examination of the rocks where the Lokapavani River 

 cuts through the hill, no quartz-veins were visible at the river-level 

 except small stringers ; although on the hills above large exposures 

 of quartz, from 4 to 15 feet in width, are observed, which, if con- 

 tinuous, would be intersected by the river. The same feature was 

 observed where precipitous ravines intersected the hill-range. 



The schists are bent, contorted, and squeezed to a great extent, 

 and the quartz-veins generally lie between their strata and have the 

 same strike, about north 15° to north 20° east. One quartz- vein of 

 some 4 feet in thickness, lying in hornblende-schist, showed peculiar 

 faulting, having been thrown twice in a height of 30 feet (fig. 9). 



Extensive gold-washing (or streaming) has been carried on during 

 ancient times in the ravines and on the hill-sides of these schist- 

 rocks ; and from the large heaps of waste stones, consisting chiefly of 

 broken quartz, the workings must at one time have been productive 

 and most likely remunerative. 



After washing the alluvium and detritus found in the ravines and 

 nullahs in a miner's cradle (or rocking-machine), also in a Bate'a, 

 small grains and nuggets of gold were found in most instances, and 

 they were mixed with particles of magnetite t, hsematite, fragments 

 of garnet, quartz, &c. 



Thegrainsof gold examined under the microscope were found to have 

 a flattened or a somewhat imperfect crystalline form, and when very 

 irregular in shape were found on their surfaces to retain in crevices 

 and hollow places small crystals of magnetite, which appeared to be 

 attached to the gold by a siliceous coating of ferruginous matter. 

 Most of the gold-grains were partially covered with the above 



* See Geo. Attwood, "A Contribution to South -American Geology," Quart. 

 Journ. Geol. Soc. vol. xxxv. p. 586 (Nov. 1879). 

 t Commonly called " black saud " by the miners. 



