478 Notes, chief y Geological, from Gooty to Ilydrabad. [May, 



are occasionally seen ; but I did not observe a fragment of the ordinary 

 mass of granite or gneiss. 



In shooting and other excursions among these hills across the N. 

 and S. strike of the strata, I observed to the eastward the ordinary 

 blue lime-stone of Cuddapah resting conformably on this sand-stone, 

 and beds of a more recent sand-stone and conglomerate capping the 

 lime-stone. This is the celebrated diamond conglomerate of Banagan- 

 pilly. That it is of more recent origin than the lime-stone and subja- 

 cent sand- stone, is proved by superposition, and by its imbedding frag- 

 ments of chert derived from veins in the lime-stone. 



These chert pebbles are recognized, not only by mineral identity, 

 but by their imbedding the oolitic looking globules which are seen in 

 myriads in the lime-stone cherts and jaspers. 



I am not aware that the difference in the age of these two sand-stone 

 beds has been before noticed, or that the existence of an older sand- 

 stone formation underlying the Cuddapah lime-stone and the diamond 

 conglomerate, has hitherto been pointed out either by Malcolmson, 

 Voysey, or other writers on the geology of South India. I found sul- 

 phate of barytes in fine crystals in the lime-stone ; and beds of a fine 

 steatite, (occasionally passing into French chalk,) which are quarried 

 and the steatite exported to Madras, and other places. It is cut into 

 pencils and extensively used by the natives for writing accounts, &c. in 

 their black books of prepared cloth, and also for smoothing chunam. 



Along the base of the hills half a mile N. E. of Dhone, the ground 

 for half a mile is covered with old diamond excavations in a bed of 

 sand-stone gravel, now covered with rubbish and bushes. North of 

 this 10 or 12 miles are the diamond mines of Ramulacota before 

 described.* 



The diamond pits of Bhone have not been worked within the memo- 

 ry of the oldest man of the village ; but he says his forefathers 

 dug there : with what success is uncertain. Their being neglected 

 may be perhaps received as a negative proof of their unproductiveness, 

 or of having been exhausted. 



Slightly thermal and perennial springs, and dykes of basaltic green- 

 stone posterior to the sand-stones and limestone formation, which they 

 penetrate and alter, are of frequent occurrence throughout the diamond 

 * Journal Royal Asiatic Society, 1843, p. 231. 



