t8S8.] Change of level in Indian Coal beds* 75 



Observed, that as no fossils have been found in it, the chances are that 

 it belongs to an earlier date*. Numerous limestones are found so much 

 alike in appearance, that it would be quite impossible to draw a line 

 of distinction between them except by means either of their fossil con- 

 tents, or their relative position to other rocks whose nature may be 

 better understood ; but where, as in the present case, such information 

 is also deficient, we must still hesitate to adopt any decided views regard- 

 ing them. 



It may here be desirable to offer a few observations on the changes of 

 levels which have taken place in our various coal fields. Why one 

 should now occupy the summit of a mountain at an elevation of 4300 

 feetf, and another remain scarcely emerged above the sea J, is a question 

 that almost suggests itself in this place ; and as the nature of coal has 

 led to the conclusion that it must at least have been formed beneath 

 estuaries, if not at greater depths from the surface§, the causes that have 

 produced its present diversified position cannot fail to excite the deepest 

 interest in our minds. In the course of the inquiry we shall find that 

 there is perhaps no portion of the earth to which the doctrine of existing 

 causes can be applied with more effect in accounting for the physical 

 changes that have taken place, than India. 



An inspection of the annexed map PL VI. will show the probability of 

 the disturbing forces having been directed in certain lines, one of which 

 extending from A, to B, may be named the secondary volcanic band, 

 from its principal energies appearing to have been exerted during the 

 secondary period. Voysey, after a careful examination of several dis- 

 tricts in Central India, embraced by this belt observes, " I have had too 

 many proofs of the intrusion of trap rocks in this district" (table- 

 lands west of Nagpore) " amongst the gneiss to allow me to doubt of 

 their volcanic origin||." Dr. Hardy, Captains Franklin, Jenkins* 

 and Coulthard in their several communications to the Asiatic Society, 

 have in certain instances expressed similar views regarding several phe- 

 nomena presented to their notice in the course of their inquiries in 

 Central India. The appearance of lines here observed in the distribu- 

 tion of trap rocks, was formerly supposed to be irreconcilable to the pro- 



* Gleanings of Science, vol. III. page 207. 



*f* At Chirr a Punji. + At Arracan. 



§ Dr. Thomson considers coal to have been formed by the slow combustion 

 of vegetable matters under great pressure and consequently at considerable 

 depth beneath the surface — vide outlines Mineralogy and Geology 1836 : others 

 refer its origin merely to the accumulation of vegetable matters in estuaries. 



I! As. Res. 1829. p. 194. 



L 2 



