Chap. 10.] w. blanford, western tndia. .57 



occurs, although the beds are generally hardened, probably through infiltra- 

 tion, so that the mode of occurrence of silica in the Lameta and Bagh 

 beds appears characteristic. It might even be suggested that the lime 

 is also due to infiltration, but the latter is very improbable, carbonate of 

 lime being a rare mineral in the traps, and the subtrappean beds being 

 sometimes almost pure limestone totally devoid of crystallization. Had 

 the carbonate of lime been derived from the overlying traps, it would 

 certainly have been deposited in a crystalline form, and probably in 

 veins and nests not uniformly throughout the mass of the rock. 



Chapter 10. — Deccan and Malwa traps. 

 The great volcanic series in general has been already described and 

 its main features and geological relations pointed 



X^TIUC 113^1 f*. it fl.T*fl <?f^PT*g 



and relations previously out in a previous paper in these Memoirs.* The 

 described. . •■.i i- 



relations oi the series to the subjacent cretaceous 



rocks and to the overlying tertiary beds are treated in the last and the 



following chapters relating to those formations. It will therefore only 



be necessary in this chapter to describe briefly the area occupied by the 



volcanic series upon the map now published, and to note such geological 



characters as especially distinguish it within the area under consideration. 



The traps occupy more than three-fourths of the accompanying map. 



All the higher ground except in the north-western 



corner is entirely composed of them, as are also very 



large tracts in the valley of the Nerbudda, and nearly the whole of the 



Taptee drainage, though in the latter, over a large area, the absolute 



surface is composed, of alluvial soil. 



Over a considerable portion of this ctnmtry the- trap» rest in almost 

 perfect horizontality. This is the ease throughout 

 the Malwa scarp, and apparently over a consider- 

 able proportion of the valley to the south of it. The same is seen, so 



» Vol. VI, Art, 3. 

 H (.219 ) 



^ 



