r|'2b . ON THE GEOLOGY 



stratification at angles of from 40° to 60°, and through the exuberant pre^ 

 sence of unessential minerals, both venous and imbedded, it exhibits modi- 

 fications of rich variety. The rock is sometimes simply constituted of 

 argillaceous matter with mica and quartz sand : in other portions it is 

 traversed in all directions by filamentous veins of pearl and calcareous 

 spars, and through these often affects the minute contortions proper to 

 gneiss, while veins of spathose iron, and of quartz rock, frequently occur, 

 disposed indiflerently to the lines of stratification. To the southward, 

 at Cattail Mangalagherry, it embraces, at least from one quarter, an elevat_ 

 ed and indistinctly stratified mass of serpentine, which sole example of 

 this rock observed in India, I regret to say, remains unexplored ; and 

 assuming to the eastward a more uniform and finely schistose character, 

 it sinks gradually to the ocean level, upon the whole affording the 

 annexed constitutional and Mineral Synopsis. 



1. Argillaceous Schist, schistose from the disposition of Mica and 



Garnets. 



2. Argillaceous Schist, laminated by Pearl Spar and Staurolite. 



3. Argillaceous Schist laminar, with pink Garnets, Staurolite, and 



Mica. 



4. Argillaceous Schist with Staurolite, Tremolite, and Mica. 



5. With Staurolite and Kyanite. 



6. Mass of Tremolite with Kyanite Garnets and Prismatic Mica. 



7. Quartz vein with Calcareous spar and pink Garnets. 



8. Quartz vein with Garnets in ranges, and perhaps Epidote. 



9. Vein of Tremolite with BroM'n spar. 



10. Mass of Tremolite, Staurolite, and Pearl spar. 



11. White Pearl spar including Bitter spar. 



12. Flesh-red Pearl spar. 



13. Vein of striated Spathose Iron, with Crystals of Pearl spar. 



14. Vein of purplish Quartz with Garnets. 



