296 Notes on the South Mahratta Country, fyc. [No. 160. 



by argillaceous matter. Werner, in the confined space that fell under 

 his observation, found both the primitive and transition schists highly 

 inclined, while the newer aqueous or secondary beds were horizontal ; 

 hence his too hasty generalizations. It is now ascertained that seconda- 

 ry strata and green tertiary beds are often found in nearly vertical po- 

 sition, and that some granites are newer than the lias and chalk ; on 

 the other hand, gneiss is often seen in horizontal beds, and Mr. Murchison 

 has lately discovered in Russia the older stratified rocks extending in 

 horizontal unbroken masses for the distance of nearly one thousand 

 miles. The value of mineral character unsupported by others, is of 

 small value as a test of the relative ages of stratified rocks ; we see la- 

 custrine strata of the Eocene period identical in all their mineral cha- 

 racters with the secondary new-red sandstone and its associated marls, 

 and certain arenaceous beds in the cretaceous formations of the Alps, 

 and even in some tertiary deposits, which can hardly be petrologically 

 distinguished from the rocks of the grauwacke group. 



Although it is quite possible that future .discoveries may prove the 

 sandstone to be equivalent to the old red, and many of the rocks, 

 classed as transition, really to belong to that period ? yet I consider it 

 preferable, for the present, to arrange the rocks of the S. Mahratta 

 country agreeably to the acknowledged geological evidence they 

 themselves exhibit, in addition to that of a mineral character, viz : super- 

 position, imbedded fragments of older rocks, intrusion with or without 

 alteration, conformable or non-conformable stratification, and this with 

 little reference to European formations. The classification will there- 

 fore, for the most part, be that of relative age. Not a single organic 

 remain, I may observe, has hitherto been discovered in the most 

 recent deposit in the S. Mahratta country to assist us to any conclu 

 sion, except recent terrestrial and fresh-water shells in the newer 

 kunker. 



The stratified rocks will be classed in the ascending order, commen- 

 cing with the hypogene, or lowest series. The plutonic and trappean 

 rocks will succeed. 



Age of Hypogene Rocks. The hypogene schists are evidently the 

 lowest in the group of normal rocks, and have suffered the greatest 

 disturbance as already observed. The lowest member in this series 

 is usually gneiss, and the highest either marble or clay slate : but 

 there are many exceptions to this remark. 



