DETAILED DESCRIPTIONS OK THE RESPECTIVE COALFIELDS. 37 
are known to have been deposited ; it has given rise to much 
speculation as to tlic probable existence of concealed coalfic^lds 
beneath the alluvia of the Ganges and the Brahmaputra. The 
unknown, but great thickness of the alluvium and tlie difliculty 
which it would present to boring operations, together with the lack 
of indications for fixing upon the best sites for the holes, have, 
however, up to the present, deterred speculators from making search 
for such fields. 
Tertiary lignites of no value have been examined in the sub- 
llimalayan rocks of the Tista valley by Dr. Oldham,^ whilst Mr. 
Mallet^ mentions two lenticular seams of soft flaky coal, one of 
which was as much as 6 feet thick in places but only extended for 
a few yards laterally. The quality of the fuel was inferior. 
Baxa Duars. — Lignite has long been known to occur in the 
Baxa Duars, near Santrabari and Jaintia on the borders of Bhutan. 
Th.e locality was visited in 1865 by Godwin- Austen ^ and later 
in 1897 by Hayden.* The lignite occurs as isolated logs in high- 
dipping Tertiary sandstones. 
According to an analysis by Dr. Saise, it is of excellent quality 
having only a small percentage of ash. It, however, is found in 
too small quantity to be of any commercial value. 
Chittacjong} — From time to time samples of brown coal or 
lignite from the Chittagong Hill Tracts have been received at the 
Geological Survey Office for examination and report. In no case 
have they been of a character to encourage a hope that coal 
occurs in sufficient abundance to be profitablv worked. All the 
specimens received are believed to be of Tertiary age and probably 
come from the nummulitic rocks, which are known to form a 
portion of the hills, where, however, Cretaceous rocks also occur. 
(viii). Bihar and Orii)3a. 
Talcliir,'^ etc. — The Talchir coalfield is situated in the valley 
of the Brahmini, which may be regarded as a tributary of the 
1 Jour. As. Soc. Bengal, XXXIII, 201 (1854). 
2 Mem., Geol. Surv. hid., XI, p. 46 (1874). 
^ Jour. Soc. Beng., XXXIV, iit. 2, p. 10<1 (1855). 
* Rec, a. S. I., Vol. XXX, p. 249. 
3 Manual Geol. India, Vol. Ill, p. 111. 
6 Blanford and Theobald; Mem., G. S. I., Vol.1, pp. 33, 38 (1856); Bali: Eec. G. 
8. 1., Vol. X, pp. 170, 17.'5 (1877). 
