S86 
Records of the Geological Survey of India. 
[voL. XI. 
Hux., Oonioghjptus longirostris, Hux., Pachygonia incurvata, Hux., Anhistrodon, 
sp., &c.,) and Estheria. Lower down follows the Damnda group, which is divi¬ 
sible into three divisions according to Blanford; upper’most lie the Raniganj 
carboniferous beds, aboirt 5,000 feet thick, consisting of coarse and fine-grained 
sandstones and shales, with intercalated coal seams, which may bo followed over 
great distances; fossils are common, but consist only of plant remains. In the 
middle Ue the ironstone shales, about 1,400 feet thick, and consisting of black 
carbonaceous shales with numerous beds of clay ironstone. At the base lie the 
lower Damuda or Barakar beds, coarse conglomerates and white sandstones 
with numerous coal seams, which arc, however, rather irregular, and thin out 
frequently within short distances; they contain plant-remains, and are about 
2,000 feet thick. The lowest group recognized by Blanfoi’d is the Talcliir 
gToup, which is composed of coarse white or bluish-green sandstones at top, 
below them of fine greenish-grey clay, which is in part sandy, then of sandy 
shales and fine-grained sandstones; finally comes as basement the so-called 
‘boulder bod,’ consisting of large I’ounded blocks of older rocks which bear traces 
of carriage by ice, and are embedded in a fine clayey .sandy matrix. Fossil plants 
occur in the upper beds of the gi’oup, but 'are very rare; the thickness of the 
group is about 800 feet. 
This completes the type of the deposits for the whole of Western 
Bengal, with exceqjtion of the Rajmahal hills. On these no detailed accounts 
are yet available'; but it is generally known that Talohir and Barakar beds are 
well develojjed there. Over them lie coarse sandstones (Oldham’s Doobraj- 
pur group), which may perhaps correspond with the Panchet group, but which 
may also have to be reckoned to the lower series. Above these follow, with 
universal unconformity, the Rajmahal bed.s, alternations of basalt (?) with 
sandstones and shales which contain the well-known Rajmahal plants. 
If we turn to H. Blanford’s second province we see a good development 
of the lower beds. The Talchirs and Barakars occur in great force; the Rani- 
ganj and Panchet beds appear to be absent, but the Rajmahal and Jabalpur 
groups, on the contrary, appear sporadically at several places. Of the greater 
part of this region detailed descriptions are still wanting, but the Talchir coal¬ 
field may be taken generally as the type.’’ The Talchir group is there found , 
resting on primary rocks ; it begins with the highly characteristic ‘boulder bed,’ 
above which follow fine-grained sandstones and blue shales with calcai-eous con¬ 
cretions. The total thickness of the group is from 500 to COO feet. A few 
plant-remains are found in the upper beds. These are succeeded upward first 
by coarse sandstones, then by shales, which attain together a thickness of about 
100 feet. These are covered by about 150 feet of carboniferous shales, above 
which come finally coarse, highly felspathic sandstones, and dark micaceous shales 
' Volume XI11 of the Memoirs of the Geological Survey of India is not as yet accessible to 
me. 
" Mem. Geol. .Surv. of India, 1, and W. T. Blanford ; Kecords Geol. Surv, of India, V, p. 63. 
