38 TALCHEER COAL FIELD. 



which here appears in situ, though possibly only a variety of the largely 

 crystallized schorl granite. Its source is at present undetermined, but may 

 probably be looked for to the West, in the granitic hills described by 

 Messrs. Hislop and Hunter as extending over the country East of Nagpur. 

 It appears probable that the granitic veins 



The granite veins, &o. ■• i m j j. -ii ,i 



probably cotemporaneous ^bove described are cotemporaneous with the 



Tfthe^'^eTsf '""'^''''''^ metamorphism of the gneiss, for the following 



reasons : — 



First, — Their very largely crystallized character, and the almost cora- 



i='<>s«,-rrom their cha- pleto Separation of the minerals composing them, 



racter Lnd composition. ^^^^ ^j^^^^ ^^^^ ^^^^j. ^.^^^ ^,f cOoUug must have 



been very slow, which, considering their small size, rarely, if ever 

 exceeding 2 feet, can only be accounted for by supposing that the 

 surrounding mass was in an intensely heated state at the period of their 

 toonc?,-Fromthechange ^trusion ; and Second,— The change which has 

 produced in the gneiss. ^^^^^ ^^^^^ j^ ^^le structure of the gneiss, as well 



as in its mineral composition, frequently to the distance of some feet 

 from the wa,lls of the veins, exhibits an amount of what may be called 

 secondary metamorphism, which a granite vein of 2 or even 3 feet 

 in thickness could scarcely be expected to produce in a perfectly or 

 even nearly cooled rock. 



Dykes of a hard green rock, apparently consisting principally 

 of quartz and hornblende, (amphibolite ?) are seen passing through 

 the gneiss in a N. E. and S. W. direction at various points near the 

 S. E. boundary of the Talcheer field, especially at Sakuasinga and near 

 the small village of Ramidi. The N. E. Fault, between Benagaria 

 and Jorasinga, which for a distance of 4 miles forms the boundary 

 of the coal measures, runs during part of its course along the line of one 

 of these dykes, as do also the N. E. Faults between Kaliakota and Ramidi. 



The rock itself is of greater age than the coal measures, since, although 

 it can frequently be traced through the gneiss up to the boundary, it 



