HISLOP AND HUNTER — NAGPUR. 367 



duced into this land before the inhabitants shall be convinced of the 

 falsehood of the alleged miracle, and shall be able to understand 

 that the seeming organisms are simple zeolitic concretions that have 

 issued from the soft subjacent rock. Nodules of the same shape are 

 found in the same formation at Sonegaum, near Kalmeshwar, fifteen 

 miles N.W. of Nagpur, but, being purely calcareous, their interior 

 consists of a confused mass of rhombic crystals. 



The Age of the Trap. — Beginning with the more recent, as v^e 

 have done in regard to the stratified rocks, we find that the amyg- 

 daloid or underlying trap has not only invaded the tertiary forma- 

 tion, but broken it up, and along with it the nodular basalt, by which 

 it is capped. The amygdaloid eruption, then, is incontestably sub- 

 sequent to the basaltic. But what age is to be assigned to the latter ? 

 It is evidently posterior to the freshwater beds on which it rests. 

 We have thus an overlying effusion of nodular basalt, which has 

 taken place after the tertiary strata, and an underlying intrusion of 

 amygdaloidal trap, which has occurred after the basaltic effusion. 

 Besides these two formations of trap, I know of no others in Central 

 India, either more modern or more ancient. Capt. now Col. Grant, 

 in his paper on the Geology of Cutch*, and Dr. Carter, in his 

 memoir on the Geology of Bombay before quoted, have adduced 

 ample proofs to show that in the districts which they have examined, 

 there have been eruptions of volcanic matter subsequent to the 

 amygdaloid ; but in all the district through which my colleague and 

 myself have been called to travel, no trap formation so modern has 

 fallen under our observation. Nor has any more ancient than the 

 overlying trap been discovered. It might be thought from the 

 occurrence of isolated pieces of trap in the lower part of our fresh- 

 water strata, that while these were being deposited, there were sheets 

 of volcanic rock already on the surface of Central India. But it 

 appears to me that there are no such fragments whose existence may 

 not be accounted for on the principle explained by Lyell in his 

 * Manual,' 4th edition, p. 446, and stated in a preceding page of this 

 paper. Besides at Bokara, and some parts of Takli plain, where the 

 amygdaloid has not been intercalated under our tertiary formation at 

 all, but where the latter, with its characteristic fossils, rests imme- 

 diately and conformably on the sandstone, there is not a trace of 

 volcanic matter to be seen. I am inclined therefore to doubt the 

 occurrence of any trap in Central India older than our lacustrine 

 deposit. In the southern portion of the Rajmahal Hills, M'Clellandf 

 informs us that amygdaloid is found underlying the coal-strata of 

 that district. The coal there is manifestly the usual so-called oolitic 

 coal of India, and therefore we have amygdaloid disturbing the Juras- 

 sic formation. But, if a stranger to the locality may be allowed to 

 express an opinion, I would respectfully submit that the position of 

 the amygdaloid is not conclusive against its comparatively modern 

 origin. It is obvious that the most recent age attributable to an 

 intruded rock, such as it is, cannot be exactly determined by ob- 



* Trans. Geol. Soc. 2nd Ser. vol. v. 



t Report Geol. Survey of India, Season 1848-9. C.ilcutta 1850. 



