THE GNEISSIC SERIES, 27 



To the north of the Penner, the succession of the foliated gneisses 

 style of the gneiss ty m §" ^° the eastward of the more eminently schist- 

 north of the Penner. oge |, and ig in tolerable accord with that just 

 described for the middle area, but here the series has widened out con- 

 siderably until it occupies almost the whole northern edge of the field, 

 the strike of the foliation or bedding being, however, more regular and 

 northerly. This great increase in width is in part accounted for by the 

 more frequent intercalation and greater thickness of the subordinate 

 quartz-rock or quartz -schist beds which here become quite a marked 

 feature in the district, and give rise to many and distinct hilly ridges. 

 The remarkable and unique feature in the schistose crystallines as 

 The subordinate quartz- a sei *i es > is ^ ie presence of these subordinate beds 

 sclllsts - of quartz-rock or quartz-schist, and these attain 

 an additional interest from the fact that they, in the middle area 

 that is, between the Penne'r and the Swarnamukhi, are to all appear, 

 ance a perfect graduating set of beds, from manifest coarse quartz-rock 

 to fine compact quartzites, very similar to those in the Cuddapah or 

 Transition Series. To the north of the Penner also, the beds as they 

 are crossed westward become finer and finer-grained until they are 

 compact waxy quartzites on the western edge of the foliated gneisses • 

 but there do not appear to be any fair cases of conglomerates or pebbly 

 beds, or even of ripplings, though the resemblance to the Cuddapah 

 quartzites is otherwise most remarkable. 1 



1 Captain Newbold also noted the character of these quartz-schists, writing of the 

 neighbourhood of Sangam on the Penned, and the rocky ridge there running down into 

 the river : " It is composed * * of a massive quartz rock in indistinct stratification, cleft 

 occasionally, like the laterite, by intersecting partings and vertical fissures which divide 

 the rock into parallelograms. * * This quartz rock passes from opaque and granular 

 to compact, translucent chert of various shades of red, brown, green, and white. It contains 

 disseminated scales of mica of a golden colour, which glitter like those in avanturine and 

 nests of brown iron ore. 



" If the marly ( ? nearly) horizontal partings are really the planes of stratification, it 

 may be inferred from its conformability that this quartz rock does not belong to the 

 hypogene series which is seen in highly inclined beds near its base, penetrated by veins of 

 granite (as seen at Pollium, a village between Doroor and Sangam), but that it is an 

 altered outlier of the sandstone mural crests which are seen from this on the western 

 horizon capping the granite and hypogene schists of the Eastern Ghauts."— Jour. As. 

 Soc, Bengal, Vol. XIV, 1845. p. 398 et seq. 



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