64 



On tlie Fossils of the Easte7-7i Portion 



[J ULY 



rock, as is seen on both sides of the Tripatty Valley. This passage is 

 also observed in other places, as near the Cuddapah diamond mines, 

 where the plentiful occurrence of basaltic pebbles shows the neighbour- 

 hood of the trap, Besides the diamond conglomerate, consisting of a 

 great variety of minerals, seams of rock crystal occur, and a fine white 

 quartz containing argentiferous galen;!, wl'ich in former times furnished 

 the country with lead. Specular and micaceous magnetic iron ores, but 

 containing much peroxide, and common iron })yrites, occur with the 

 galena. As far as I have obser%'ed, the sandstone always rests con- 

 formably on the schists, although from its jointed siructure it occasion- 

 ally, when elevated, appears to meet the subjacent rock at a more or less 

 obtuse angle. 



The schists on which the sandstone rests, vary very remarkably in 

 colour, being in diiferent places blue, red, green, or pure white, in which 

 they seem to bear some relation to the incumbent sandstone. They are 

 also occasionally flinty or jaspideous. Sometimes they are wanting, the 

 sandstone resting directly on tiie limestone, of which the schists are 

 evidently merely the upper beds, and into which they pass insensibly, 

 although it seldom happens that considerable effervescence does not 

 occur on examination by tests. It is in many places impossible to 

 say to which portion of the series any particular specimen belongs. 



Voysev has classed the schists with the sandstone under the name 

 of" (the clay slate formation ;)" I have, however, preferred to designate 

 the deposit " argillaceous limestone," a term used by him in one of his 

 sections as applicable to the limestone, and which well expresses not 

 only the general character of the rock, but that also of the upper schis- 

 tose beds. 



Tlie limestone is a compact rock, but the strata are usually thin, and 

 are often intersected by vertical partings, a circumstance which fre- 

 quentlv limits its use in ornamental architecture. Its most common 

 colour is a light blue, passing into black ; but it occasionally occurs 

 of a nearly pure white, and affords an admirable material for. basso- 

 relievos. On this stone the finest sculptures of the ruined city of 

 Amrawuty are executed, and for delicacy of workmanship they have 

 perhaps never been surpassed. Were it not for the occurrence of small 

 crystals of quartz, the same quarries would furnish an excellent litho- 

 graphic stone. Near Cuddapah the dark variety is the common building 

 stone, and many fine columns, caryatides, and cisterns are composed of 

 it. The stone is applied to the same objects in the southern Mahratta 

 country, and along the course of the Godavery towards Nagpoor. 



To the south and east of Cuddapah, a narrow valley, nearly 150 miles 



