THE GNEISSIC SERIES. 2$ 



by mica. There are coarser and finer beds, but no approach to a 

 dense fine-grained quartzite, and in the less coarse beds lamination 

 is recognisable ; though, on the whole, the sedimentary origin is only 

 manifest in the distinctly and "for long distances bedded character of 

 the rock among the other gneisses. The debris of these beds scattered 

 over the flats below the ridges is quite as peculiar as the rock itself, 

 being a sort of sharp gravel of glassy quartz. This Narasimhakonda 

 quartz-rock is easily recognisable all over the district. To the west 

 of these ridges are further beds of this rough quartz -rock, which show 

 better to the north-west at Tarndipali as they drop down to the Penner 

 alluvium. The beds here are still of the same character as those of 

 Narasimhakonda, very coarse, crystalline, glassy, and laminated. Still 

 going west, a strong band of frequent out-crops and ridges of quartz- 

 rock runs from Suripalem on the right bank of the Penne'r, south and 

 south-east through Nandiwai, Lingumpilly, and Davanavamur to the 

 Kandleru valley, which still possess generally the character of the Nara- 

 simhakonda rock, but have frequent intercalations of finer and more 

 compact strata. This band is the eastern arm of a fan-like or divergent 

 strike of the foliated gneisses which commences at and spreads north- 

 ward from Ingoort, and it will be seen further on how the rocks vary 

 in the western arm. 



In this the Ingoort neighbourhood, the first ridge west of Lin- 

 Finer and compacter gumpillyi is of various styles of quartz-rock, from 

 varieties about Ingoort. the yeiy coargely crystalline ^ ^ mQre ^^ 



granular, among which are lenticular seams of schistose hornblendic beds. 

 There are compact grey and yellowish quartzites, looking like strino-s of 

 vein quartz, running in the bedding, and, again, coarsely crystalline 

 granular rock like that of Narasimhakonda. About a mile further west 

 the main or highest ridge forming the western side of the Ingoort 

 nucleus is almost entirely made up of thick beds of pale grey and 

 greenish quartz-rock or quartzite, a quartzite which more and more 



1 Among the ridges west of Lingumpilly there is a poor outcrop of beds of grey 

 crystalline limestone striking north-north-west with a vertical dip. 



( 137 ) 



