TALCHEER COAL FIELD, 41 



The gneiss occasionally assumes so closely the appearance of granite, 

 that were it not for the evident identity in origin of these portions ■with 

 that of the more typical gneiss surrounding them, they might almost be 

 mistaken for a true granite. This is well seen, among other places, near 

 the village of Kokodong, on the borders of the Talcheer field, where large 

 bosses of apparently highly porphyritic gneiss, containing disseminated 

 garnets and imperfect crystals of adularia felspar, rise above the 

 general surface of the ground, and distinctly show the effects of exfolia- 

 tion. Also, in the bed of the Brahmini below Santapara, the same gneiss 

 appears, weathering into the form of rounded bosses, which scale off at 

 the sm-face in the same manner as many granites. Occasionally, the 

 whole weathers into rounded masses imbedded in soft decomposed gneiss, 

 presenting much the appearance of a sedimentary boulder bed, 

 for which indeed it might readily be mistaken, when occurring, as it 

 frequently does, just at the junction of the gneiss with the coal 

 measures. 



The accompanying Sketches will give some idea of the appearances 

 presented. 



fh 





Wit^""' 





Fig. 2 shows a mass of this rock traversed by a small fault near 

 Karakprasad, and illustrates the mode of its origin and the different 

 stages of decomposition. Another good instance of the same action is 



G 



