Chap. XL. ] 
VIZAGAPATAM : CHIN I ELAVALSA. 
ni:} 
some untwinned felspar, calcite, and sphene ; whilst at yet aiiotlier spot 
it was composed of sphene, pyroxene, labradorite, and sea polite, all 
present in abundance, with a little iron-ore (? ilmenite). 
The overlying rock is also somewhat variable in composition. At 
one place it is composed of biotite, rhombic 
oiie-gneVssas ' pyroxene, labradorite and apatite, with a little 
quartz, whilst at another it consists of pink 
garnet, hypersthene, augite, black iron-ore, labradoiite, and apatite. 
In each case the rock is fairly fine-grained and shows gneissosa .structures. 
They are rather difficult to name but may be described as noritic 
gneisses, or as biotite-pyroxene-gneiss and garnet-pyrox ne gneiss, 
respectively. 
Reference to Fig. 2 of Plate 55 shows that the noritic gneisses, manga- 
nese-pyroxenites, and calcareous gneisses, occupy a position at the junction 
of the khondalite and gneissose granite suggesting that they may be either 
the basal beds of the khondalite series or contact products resulting from 
the interaction of the gneissose granite and the khr ndalite. The latter 
hypothesis is extremely improbable, considering the probable chemical 
composition of the various rocks ; the former hypothesis may be true 
as regards the calcareous greisses. but not for the other rocks. If the 
manganese-pyroxenites have any connection with the kodurite series 
of this district, then they must be regarded as in all probability intrusive. 
Both here and at Chintelavalsa, however, they difTer from the manga- 
nese-pyroxenites seen elsewhere in that they frequently contain 
graphite. This constituent, may, however, not be an original one ; 
but may have been obtained from the khondalite series, a formation 
which is characterized by abundance of graphite. 
This occurrence possesses no economic value ; for the rocks are 
mostly very fresh and altered only at the outcrops. 
22. Chintelavalsa. 
Ab with Taduiu, my attention was firsu drawn to the occuirence 
of manganese-ores near this village by Mr. Middlemiss, who found 
pebbles and boulders of rhodonite and other manganese siUcates exter 
nally altered to manganese oxides, scattered at intervals along the 
road from Burjavalsa to Chintelavalsa. He did not. however, have time 
