iS MIDDI.I.MISS : Till: (il.olJK.V OF 1DA1! STATK. 



narrow straight bands, running parallel to the foliation, and of a 

 darker smoky grey colour (seen to the right of the railway cutting. PI. 1 , 

 fig. 2). Here all the stages are seen in the progress of mylonitisation of 

 the calcitc ground-mass, from one with simply bent cleavage flakes 

 as in (12137), PI. 8, fig. 4 to one in which the calcite has become 

 converted into a microcrystalline medium in which larger grains 

 of quartz, felspar, diopsidc, sphene and zoisite appear to he left as 

 'eye?,' or like, corroded phenocrysts in a granite porphyry (12145). 

 This mylonitised ground-mass of minute calcite grains is of a dull, 

 dark grey colour, and shows a rude flow structure round the larger 

 grains, especially well marked where the graphite has been drawn 

 out into long smudges. 



The zoisite in these examples is full of inclusions, or is in ragged 

 interrupted plates as if crowded with, or intergrown with, the 

 ground-mass of quartz-felspar mosaic, and shows abnormally 

 brilliant interference colours of a very beautiful shade of deep violet - 

 grey or sapphire-blue, in place of the ordinary steel-grey as ex- 

 hibited by most minerals a little below the yellow of the first order. 

 In slightly thicker sections the yellow of the first order in this 

 mineral appears of a slightly greenish, or primrose, yellow, instead 

 of the usual yellow ochre. In slide No. L2144 of this rock the zoisite 

 apparently passes over by gradation into cpidote. Slide 12146 

 shows much diopside, and is typically equidimensional as to grain. 



The calc-gneiss from 2 miles north by east of Khed Brahma 

 (..-.''.,, 12147), at the locality of the allanite granite, has much calcitc, 

 a fair amount of quartz-felspar mosaic (orthoclase and a very little 

 microcline), diopside and zoisite, all in grains. There is a con- 

 siderable amount of distinctly pleochroic sphene and green horn- 

 blende in hypidiomorphic and very attenuated sections, graphite 

 in ragged tufts, and no mica. 



From 1 mile north of Vadali, among the varieties of the banded 

 calc-gneiss, comes a compact, fine-grained, mylonitised specimen 

 in which there is hardly any calcite, some quartz-felspar mosaic, 

 ragged (0 diopside plates, garnet in large irregular aggregates of 

 minute grains. Zoisite and also sphene can be detected ( 3 2 $), 121-18). 



A specimen ( 3 ~ 7 ' 6 , 12149) from the northern edge of Asai hill, 

 is remarkable for the bright emerald-green pyroxene, besides wollas- 

 tonite, sphene and other ordinary calc-gneiss minerals. There is 

 also a replacement of sundry minerals by dark, dusty, amorphous 

 silica ( ? ) ; specimens 3-./0 and 3 2 . 2 - 7 (12150), from the S.E. extremity 



