Chap. IV. 1.] metamorphic rocks. 51 



traceable only for a mile or so in a continuous line. An apparent conti- 

 nuation of this bed was observed further to the east-north-east in a very 

 dense scrub-jungle, but owing to the absence of any marked points, the 

 true position of the locality could not be determined. 



The limestone at Polliam is interbedded with a compact homblendic 

 gneiss, the foliation of which varies in direction between east-north-east 

 and west-south-west (E. 25° N.), and north-east by east to south-west by 

 west (E. 38° W.), while the dip is 70° to the southward. Near to 

 Kurrinculputty, 3 miles east-north-east from Polliam, there is a boss 

 of this gneiss, where (as will be seen on a reference to the map) the re- 

 markable straightness of the beds of limestone is broken, a necessary 

 widening out of these having taken place in order to fill up the vacancies 

 caused by the crumpling of the beds of gneiss forming this boss. At the 

 same time, the alternating beds of gneiss and limestone to the south of 

 this do not show such a fold, but preserve the direct strike. Intrusions of 

 granite have occurred to a limited extent to the north. 



Variations in the colour and texture of the limestone in this locality 

 are pretty frequent. Nearly pure white marble, both fine and coarse- 

 grained, lies immediately round the south-west base of this boss of gneiss, 

 while on the opposite side is a largely crystallized variety, in which 

 separate crystals of carbonate of lime (Calcite) are easily distinguishable : 

 generally of a pink colour. A beautiful pink variety, admirably adapted 

 for marble slabs on account of its close texture and absence of folia of 

 foreign minerals, is of frequent occurrence in several bands. East of 

 Keeranore, there is a bluish-coloured band, and a wide spread of pale grey 

 limestone forms a foundation for the village of Veerarlyputty, 2 miles 

 north-east of the gneiss-boss mentioned above. 



Other minerals, such as Chlorite and Mica, enter more or less into 



the composition of most of the limestone of this 

 Included minerals. 



part of the country, but in some beds these are 



very rare, and sometimes totally absent. When occurring to any extent, 



(273) 



