BARAKARS — NIZAM^ DOMrNIONS. 65 



coal. This circumstance can only be due either to the fact that the seam 

 was not deposited where the borings were made ; or, that having been 

 deposited, it was denuded before the rocks of the Kamthi series were 

 formed. If there were a section freely exposed, this question could be 

 settled at once ; as it is, we can only approach it through the considera- 

 tion of what might be expected to appear under these two suppositions, 

 and the agreement therewith of such facts as we know. It might be 

 thought that the discussion is practically an idle one ; that it mattered 

 little whether the coal had never been deposited, or whether it had been 

 removed. But it is not so ; the hopes regarding what is there now 

 depend a good deal upon those same conditions — removal or original 

 limitation. 



On the supposition of its being the remains of a once more extended 

 spread of coal, one might expect it to exhibit and maintain the uniformity 

 of thickness and quality that usually attends deposition on a wide 

 scale ; whereas, if these frequent blanks are due to original limitation, 

 we must expect the coal to exhibit the irregularity that befalls every sort 

 of formation near a margin of deposition. 



The supposed pre-Kamthi denudation may have been of two sorts : 

 a greater, involving a lateral disturbance (undulation) of the coal. mea- 

 sures, and the wearing down of the irregularities so produced, resulting 

 in very decided unconformity (intersecting planes of stratification) with 

 the next succeeding deposits ; or a lesser, due merely to change of level 

 and consequent erosion of the latest deposits ; resulting also in a marked 

 kind of unconformity — general parallelism, with occasional abruptly abut- 

 ting stratification, such as may everywhere be seen between old and new 

 alluvial deposits. Every case of denudation must in some degree pro- 

 duce one or other of these forms of unconformity. 



This term is also sometimes applied in the mere sense of discontinuity ; 

 when deposits are not co-extensive : where upper deposits overlap, or 

 spread beyond, lower ones, without any contrasting contact of the strata. 



( 65 ) 



