Anniversary Address. 25 



The Indian surveyors show that the Mahadeva sandstone (or 

 Bangnapilly rock) surmounts the Damoodah beds, believed to be 

 Permian, and that the Talcheer group, which underlies them 

 rests on gneiss, hornblendic gneiss, schist, and quartz schist ; and 

 in the Mahanuddi River to the southward of the Talcheer 

 coal-field, which runs through the basic formations, a small 

 amount of diamonds has been found. "Where the Talcheer beds 

 meet the hornblendic rocks by a fault on the Takiria River, and in 

 the Ouli which flows to it from the Mahadeva rocks, gold is 

 occasionally found. 



North of this region the great Vindhyan rocks stretch across 

 the country north-north-easterly, being the upper of three 

 groups resting on gneiss and granite. These are described in 

 the second volume of the " Memoirs of the Survey," by Professor 

 H. B. Medlicott ; and both he and Dr. Oldham give good reasons 

 for placing the Vindhyan series in connection with the Damoodah, 

 or Coal measures of the Talcheer field, and therefore they are 

 far removed from the Bangnapilly beds, belonging to the Mahadeva 

 group to the southward. 



Mr. Medlicott shows that the diamond beds are not all of one 

 age, and instances the mines at Punnah, 600 or 700 miles north 

 of Cuddapah, which he places close to the junction of the lower 

 and middle groups of the Vindhyan series, at the northern edge 

 of the Eewah tableland, in the shales, to which latter group they 

 belong. This at once places them far below any possible Jurassic 

 or even Triassic strata. 



The Punnah diamond diggings occupy not more than twenty 

 acres. The diamonds are found in a conglomerate belonging to 

 relics of old spurs and outliers of the tableland. Pine grits 

 among red and green shales, and a few beds of sandstone, 

 constitute the strata. 



At Kumerea (another field), the diamond bed is in an incoherent 

 ferruginous sandy earth, of variable thickness and undecided 

 position. To the east it is modified, and near Bridjepurit consists 

 of two feet of conglomeratic sandstone, resting on strong beds 

 of sandstone, and is worked at the surface. The " kukra," or 

 diamond bed, is sometimes an incoherent ferruginous and sandy 

 earth, variable in thickness and position as as are the beds with 



