CiiAi'. XXX.] 
NORTH KVNARA inSTRICT. 
649 
All the above rocks, both inanganiferous and non-manganiferous, 
are banded and usually fine-grained with granulitic structures. 
The granite-veins or apophyses that pierce the gneissic rocks are very 
interesting ; for they often contain various mangaui- 
ferous minerals, which were no doubt formed by the 
absorption of materials from the gneisses when the granite was intrud'id. 
One vein, consisting of felspar (intergrowths of microcline and oligoclase) 
with a little interstitial quartz, contains an abundance of accessory mmer- 
als. One of these is a pyroxene showing the blanfordite type of pleochro- 
ism, and a second is a prismatic hair-brown mineral that microscopic- 
ally shows all the characters of sphene, but has the rather mi- 
usual type of pleochroism peculiar to the manganiferous variety of sphene 
— greenovite. As it reacts for titanium and very slightly for manganese 
it probably is greenovite. 
North Kanara District. 
In I'JOi the late Mr. A. M. Gow Smith reported the find of several 
deposits of manganese-ore in the area just north of Supa. They mav be 
divided into i blocks :— 
1. — In Virkhol, Konada (15° 16—74° 34') and Kalavahal. 
2. — In Aveda, Badgund, and Konada (15° 18'— 7-L° 37'). 
3. — In Puseli. 
4. — In Shingargaon. 
According to Mr. P. N. Bose, who prospected this area in March and 
April 1906 on behalf of Mr. P. Gow, administrator of the late Mr. Gow 
Smith's estate, there is in this area to the north and north-east of Supa a 
large expanse of the Dharwar Series. Banded hematitic quartzites form 
well-defined ridges running in a N. — S. direction, roughly parallel to 
the strike of the rocks, whilst in the low ground between the ridges phyl- 
lites and other softer rocks are met with. These rocks are probably a 
continuation of the Castle Rock Band of Dharwars seen at Talevadi and 
Bhimgad. Highly granitoid gneisses are foimd to the north of the 
Dharwars in the neighbourhood of Shingargaon and Kodalgaon. 
The manganese-ores consist of pyrolusite and psilomelane and are of 
lateritic (lateritoid) origin, resting on the outcrops of the Dharwar rocks ; 
