STRATIGRAPHICAL ELEMENTS: CRYSTALLINES, ETC. 71 



quartz, and a pale greenish mica. The felspars appear dull white in 

 the hand-specimen, and dusty grey in the section. Pseudo-microcline 

 structure is noticeable in some of them. They are much broken at the 

 edges, forming a quartz-felspar mosaic. Alteration product of one 

 of them in tassels with development of secondary mica. The quartz 

 is much the same as in the last specimen, but there is also secondary 

 quartz running in bands through the felspar. The mica is torn into 

 shreds, broken up, and bent. Accessories are apatite included in 

 the felspar, and a very little magnetite. 



No. ¥ fg, north-east of 2198 ft. hill, Sirun river, near Turbela. 

 In the hand this specimen appears to be almost of the tabular-foliated 

 type. Under the microscope it is seen to be a completely rolled out 

 and powdered up rock composed chiefly of layers of quartz and felspar. 

 The latter, when the irregular grains can be distinguished in the 

 much-disfigured mosaic, is seen to contain a large number of inclu- 

 sions of the same sort as was noticed in the felspar of No. -gf-j- (see 

 page 58). Between the layers of quartz felspar mosaic, dark mica 

 chiefly, but also pale mica, lie in parallel wavy lines, running round 

 the occasional eyes of felspar and producing with the magnetite, 

 which also follows this course, a genuine foliation of the rock. 



No. -fl-g, sixty yards south of main gneissose-granite boundary, 1 

 mile west of Bela N. on the road to Mansehruh. Aplite vein, very 

 coarsely banded, 2- feet thick, among quartz-schists. Composed 

 chiefly of felspar and quartz, the former ophitic in large crystals 

 round the latter, which meanders in veins and strings through it. 

 There is a peculiar striping of the felspars, giving between crossed 

 nicols in certain aspects the appearance of a microperthitic inter- 

 growth. It is probably a pressure effect. Mica, dark and pale, is 

 present in very small quantity. 



No. g-g-Q-, Bela N. Fine-grained aplite vein in coarser gneiss- 

 ose-granite. Has a fine-grained almost euritic texture, and is com- 

 posed of an intimately mixed quartz-felspar mosaic. White mica is 

 present, and also schorl. The coarser rock in which the vein occurs 



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