72 MIPDLKMISS: THE GEOLOGI OF IPAR STATE. 



bably a rare occurrence anywhere, as distinguished from 

 igneous pyroxenite masses which usually are of higher specific 

 gravity, contain more iron, and are darker coloured. The regular 

 and banded appearance of this white pyroxene, its association 

 with beds of crystalline limestone and with quartzose varieties — 

 the whole series being sandwiched between thick beds of sericite- 

 biotite schists -is certainly suggestive of a metamorphio origin 

 for it. Its pale colour, low specific gravity, and other characters 

 dependent on its small percentage of iron, are also in favour 

 of the same view. Also it shows no passage into any gabbro-like or 

 other igneous rock such as commonly happens with pyroxenite 

 masses — felspar being entirely absent from all its occurrences. The 

 above considerations seem to be very strongly in favour of a thermo- 

 dynamical origin for these beds, by the metamorphisni of impure 

 limestone or dolomitic limestone, an explanation which, apart from 

 the massiveness and purity of the diopside layers, is natural enough, 

 since diopside crystals are frequently and typically found in a 

 similar association. 



Before, however, closing the description of the white pyroxene 



fc _ . ,. ± rocks of Bamanvada, it is necessary to men- 



Massive white pyro- . . J 



xone-rock S.E. of tion a somewhat similar occurrence of what 

 ^ hetah - appears to be a massive and quite imbedded, 



coarse- to medium-grained rock with exactly similar white 

 pyroxene in its composition, together with other minerals as 

 detailed below. It is found in a few very isolated lumps, 

 about 20 yards across, protruding above the alluvium (and with 

 crystalline limestone a little further on) 1} miles S.S.E. of Bhetali 

 (specimen No. 3 2 6 \— 3 \\— 12390, 12391, PI. 12, fig. 3). It is thus out 

 of all actual connection with the ordinary bedded white pyroxene 

 rocks near Bamanvada although in the same neighbourhood and 

 line of strike. Besides much white pyroxene and a little tremolite 

 in this rock, there is also a small amount of quartz and a little microc- 

 line ophitically surrounded by the pyroxene, and a considerable 

 amount of manganese ore, probably pyrolusite, between and sur- 

 rounding the white pyroxene and as coatings round the edges of 

 the pyroxene crystals and along veins and cleavage cracks. There 

 is also some iron ore and sphene. The manganese ore is in sufficient 

 quantity to give the rock a mottled or grey appearance. The 

 massive habit of this rock and the presence of microcline, quartz- 

 iron ores and sphene certainly differentiates it from the ordinary 



