UPPER GONDWANA SERIES. 49 



which the greater part of the surface is bare quartzite, of brown and 

 drab colours, with a quaquaversal dip. The apex of the dome lies consider- 

 ably westward of the true centre. Though cut into by a deep ravine 

 on the north side, the arch of the dome is not cut through, and the under- 

 lying gneiss is not seen. No point of actual contact with the gneissic 

 rocks is seen, but to the north of the dome is a large dyke of dioritic trap 

 of the gneissic series of dyke which is older than the Kadapa system. 

 North of this dyke is another outlier, also a domoid anticlinal, but of 

 much smaller size, being only about | mile long by | wide, but consist- 

 ing of bluish-drab and grey quartzites, unlike any of the beds seen in 

 the greater dome. These two faulted anticlinal outliers complete the 

 list of outliers of Kadapa age south of the Kistna. 



CHAPTER IV— THE UPPER GONDWANA SERIES. 

 The formations belonging to this very interesting and important 

 division of the mesozoic rocks occur in numerous patches, mostly of small 

 size, lying, with a few exceptions, along the eastern boundary of the 

 gneissic area and dipping under the younger lateritic and alluvial 

 formations. The exceptions are a few inliers situated within the area 

 of the younger formations. These, with the exception of two inliers on 

 the western border of the Kistna delta near Guntur. are of triflino- 

 importance. Counting large and small patches, they number twenty-four, 

 of which two possibly may be considered rather doubtful, being referred 

 to this series solely because of their position. These will be referred to 

 again further on. Besides the patches which were of sufficient size 

 to be mapped, there are many other small exposures of these Gondwana 

 rocks in wells and water-courses, showing that they are really much 

 more extensively developed than they appear to be on the map. If 

 the alluvium could be removed, the Gondwana beds would show a surface 

 several hundred square miles greater in extent than that which they now 

 d ( 49 ) 



