294 Records of the Geological Survey of India. [voL. xi. 
In tlie Madras region appear tertiary sandstones of uncertain age (Cuddalore 
and Rajamundiy sandstones) which I have ignored in the little map. 
To complete the picture of the Indian succession of formations, there re¬ 
main hut a few words to say on the bathrological position of the Deccan trap, 
which occupies the entire western half of the Indian peninsula proper. There 
can be no doubt that the volcanic eruptions to Avhich the Deccan trap owes its 
origin began already with the commencement of the Jurassic epoch, as is clearly 
shown by the alternation of trap flows with plant-bearing sandstones in the Raj- 
mahal hills. The principal period of eruption lay within the cretaceous era, and 
chiefly about the end of it, as the Bagh beds (Upper Greensand) are covered 
directly by flows of genuine Deccan trap.^ In Kachh the basalts rest on 
aptian beds, and arc covered by nummulitics.^ In Sindh also they form the 
lowest exposed rock.® On the lower Godavari, on the contrary, Hislop'* * deter¬ 
mined certain fossiliferous beds, which are intercalated between the basalts, as 
lower eocene : finally, the fresh-water shells which have been described from the 
intertrappean beds of the neighbourhood of Nagpur^ have in their general “habi¬ 
tus” a yet far younger stamp. It would appear from all this, that the outbursts 
of ei’ujrtive rock lasted through very long periods, beginning perhaps with the 
close of the trias period and extending to beyond the eocene period. It is in¬ 
teresting to observe that this period agi'ees pretty closely with the jjcriod of ele¬ 
vation of the southern part of the Himalaya, while its marine deposits, of the 
period of the later mesozoic foi-mations, disai^peared southward of the first crys¬ 
talline zone, and to the south of the Indian peninsula the outlines of the conti¬ 
nent were subjected to constantly progressive changes through extensive irrup¬ 
tions. 
I have now sketched in bold outlines the succession of beds composing the 
Indian continent, with the exception of the glacial formation and alluvium. 
These two I can pass over with a clear conscience, as they appear of no imjiort- 
anee for the prirposo of this essay. On the little map I have shown only the 
aUuria of the Ganges and Brahmaputra; it stands to reason that the other great 
rivers are accompanied by alluvial formations; many also of the superficial 
deposits in Rajputana may have to be considered as alluvia, but with regard to 
the small scale of the map these features could bo conveniently left unnoticed. 
If we look back, the following points may be deduced as chief results of the facts 
already stated:— 
I. In the palffiozoic formations the slaty facies with marine fossils occurs only 
in the north and north-west, in the Himalaya, the Salt Range, the Hindu Kush, and 
the Suliman Range. Everything else belongs to the sandstone facies and contains 
no fossils. 
* Blanford: Mem. Geol. Surv. of India, VI. 
- Wynne: Mom. Geol. Surv. of India, IX. 
® W. T. Blanford: Records Geol. Surv. of India, IX, p. 9. 
* Hislop : Quart. Journ. Geol. Soc., Loudon, XVI. 
® Hislop: Quart. Journ. Geol. Soc., London, XI and XVL 
