34 MALLET^ VINDHYAN SERIES. 



middle is pure, laut the upper part again is largely mixed with, silica ; in- 

 deed the boundary between this rock and the silicious ones above is not 

 well marked, the passage between the two being very gradual. The thick- 

 ness of limestone south-east of Khone Khas is perhaps 300 feet, but this 

 is considerably increased between the Kunhm- and Rehund. At Kujrahut 

 the thickness of highly inclined strata is so great as to render it hkely 

 that they are repeated by doubling up. 



West of the Rehund this limestone no longer forms a constant 

 member of the series. Frequently it is entirely absent, while in some 

 sections great, but very local, accumulations are found. Such are well 

 seen on the pass south of Berouli, and better still forming bare rugged 

 little hills south of Bergurah. It is along here, however, that the most 

 conflicting cases occur of confusion with the limestone of the slate series. 

 In several excellent river sections there is found close to the north limit 

 of the slates a limestone unmistakably interstratified with the older 

 rocks, and the question is, whether all the limestone seen here may not be 

 this rock, the two being often undistinguishable in ordinary ground sec- 

 tions. The older rocks, however, universally exhibit a state of extreme 

 compression and flexm'e, whereas the limestone of the hillocks near 

 Bergurah only shows a moderate and steady disturbance ; there is, more- 

 over, a far greater thickness of it than has ever been observed in a clear 

 section of the older limestone. Whatever series this limestone belongs 

 to, its sudden appearance and disappearance is most difficult to account 

 for ; in fact it seems impossible on any other supposition than that of 

 original limitation, unless indeed by the most arbitrary and imsupported 

 use of faulting. Within half a mile east of the extensive spread of 

 limestone this rock vanishes from the section. We find thin sandstones, 

 with fine-grained and sub-porcellanic shales well to the soui/i of {i. e., 

 inside) the run of the massive limestone ; they exhibit considerable 

 contortion, and the lowest rock seen is of an unusual type, a bright 



( 34 ) 



