1832.] On the Gj/psum of the Himalaya. 295 



in such magnificence at the caves of Sansardhdrd, but actually give a 

 coating to the bed of the streams, and are the cause, I conclude, of the 

 enormous excess of local conglomerate that appears throughout the whole 

 of the ranges, of which MasuriTiba and Bhadrdj form such promi- 

 nent features ; the latter mountain terminating the range towards the 

 Jumna, whilst the eastern or opposite extremity, under the name ofSkanda 

 Dehi, is washed by the Ganges. The yellow color of some varie- 

 ties of the gypsum may depend on the contact with sulphur*, the 

 abundance of which mineral may be concluded from the sulphuret- 

 ted waters above alluded to : — that it was so in former times, is suffici- 

 ently shewn by the existence of the gypsum itself. Whether it is not daily 

 forming may be a matter of doubt, at least in the above localities: we 

 find independent masses of tufa apart from the proximity of springs and 

 water, the course of the latter having changed or dried up ; at least 

 the argument would stand thus on the discovery of a mass of calca- 

 reous tufa similarly situated to the gypsum deposit of SalkoVh 9 

 or that of other countries, not forgetting the primary deposit of Dau- 

 buisson at Cogne ! 



If therefore where carbonate of lime, sulphur, and water are 

 abundant, the chemical change above mentioned, is allowed, or is 

 supposed from analogy to be a probable consequence, gypsum can no 

 longer be entitled to a place in either primary transition or secondary 

 classes ; but must be considered as an adventitious formation common 

 to all ages, and produced by causes analogous to the present rapid 

 formation of calcareous tufa. Amongst our primary and transition 

 rocks, none can be assimilated to the stalactitic carbonate of lime ; 

 amongst our secondary or latest class of general rocks, there is 

 none like the gypsum, that is to say, we know of none actually 

 forming at this day. Causes that led to the formations of such 

 abundance of gypsum formerly, may from unassignable reasons, no 

 longer exist; and those which produce the tufaceous carbonates, 

 then at rest, may now be in full vigor. 



The above reasoning is not affected by any account of a gypsum 

 deposit that I have met with, and although the regular strati- 

 fication or alternation of gypsum with clay slate, as above alluded 

 to, may at first be a startling objection to the proposed theory, it 

 will on examination be easily accounted for. The above discovered 

 deposit of gypsum was assumed actually to consist of strata, but this 

 is somewhat doubtful. 



* Is not the yellow color due to the presence of oxide of iron ?— Ed. 



P 



