Chap. XL.] 
VizAGAPATAM : KODTTR. 
106^ 
lenticular masses of ore were extracted in excavating this pit, and that 
they seemed to run together below and form a mass having the 
general shape of the pit. 
The ore-body at the western end is not really a continuous band 
of ore, but consists of lenticular and boulder-like masses of manganese- 
ore in wad and lithoniarge ; there are also often small pebble-like 
masses of ore in the patches of wad. usually towards their centre. 
A careful examination of this and similar occurrences of wad at other 
parts of the deposit makes it evident that these boulder-hke masses of 
ore are the result of the replacement of the lithomarge by oxides of 
manganese, wad being the first product, passing on the accession of more 
manganese oxide into manganese-ore. Plate 48 illustrates a section 
seen at this end of the quarry, the black patches (0) being manganese- 
ore, the white lithomarge, and the half tones wad. 
The pit H, separated from the main quarry, was not deep, and 
exposed an ore-band striking N.15 "W., not more than 3-5 feet wide, 
and, as far as could be seen, also composed of isolated masses. This 
strike brings it to the west end of the main pit at a point some 30 yards 
east of the ore-band noticed in the previous paragraph, so that it is 
probably another ore-band. 
The ore-band at the east end of the quarry is best studied in the 
N. E. corner B A (Fig. 82) of the quarry. This is the portion illus- 
trated in Plate 50, Fig. I, where coolies are seen actively engaged in 
quarrying the ore. On the way down the zig-zag path the soft rocks are 
seen to be composed of the various decomposed rocks originally composed 
of apatite, manganese-pyroxene, spandite, and felspar, and already 
noticed on pages 1062 to 1064, 
The rock of immediate interest is the mass of spandite-rock seen 
in the wall A B (see page 1063). In places the spandite-rock is altered 
to pyrolusite and psilomelane, and at the S. E. end of the cuttmg this 
alteration is more frequent. Here there is an apparent dip at 45° 
to S. E. and some bands of spandite-rock have been changed to 
shiny psilomelane at the centre. 
There is also another band of brecciation due to the filling in of a 
fissure by spandite, clay, ore, and kaolinized felspar-rock. In the comer 
