250 GEOLOGICAL SURVEY OF INDIA. 



Haidarabad in the Deccan to the western coast between Ratnagiri 

 and Goa. Of the several rock series found there the gneissic is the 

 mostly widely developed, and occurs chiefly in the eastern, southern, 

 and south-western parts of the area, while the Deccan trap covers 

 very nearly as large an extent of ground in the western and northern 

 parts. The iron clay or lateritic beds cover a much smaller area, 

 but claim notice on account of their remarkable features. They 

 cap all the highest ridges and peaks in the Kolhapur and Belgaum 

 mountains, rendering them perfectly table-topped, and in consequence 

 favourite sites for old Maratha strongholds and forts. 



In continuation of Mr. Ball's survey of the Aurunga and Hutar coal 

 fields (see " Memoirs," XV., Parts I. and II.), Mr. Griesbach, during 

 1879, mapped and described some 900 square miles of G-ondwana 

 rocks in Ramkola between Takapani and the Rer river. The ground 

 is the easternmost prolongation of the great central area of South 

 Rewa or the Son, extending westwards to near Katni on the 

 Jabalpur railway and south-eastwards into the Mahanadi basin to 

 near Sambalpur. In Kathiawar, on the southern confines of the 

 Arvali metamorphic region, Mr. Fedden completed the survey of 

 some 1,900 square miles in continuation to the south of his previous 

 season's work, besides making some preliminary traverses of 

 adjoining ground. Nearly the whole area is occupied by the great 

 eruptive formation. It is mostly stratified, having a slight inclina- 

 tion to the south, but huge dykes traverse it in various directions,- 

 forming prominent ridges across the low undulating country. The 

 isolated central hill forming the sacred peak of Girnar is a mass of 

 thoroughly crystalline rock, which seems to be the core of a volcanic 

 focus. Owing to the scattered position of the outcrops in a wide- 

 spread waste of sand. Mr. Hacket was enabled to add a very large 

 area (more than 10.000 square miles) to his previous study of the 

 Arvali region, extending to the south-west as far as Erinpura, The 

 Vindhyan strata were found to cover a large area to the north and 

 east of Jodhpur; they everywhere rest flatly iqaon the old rocks, 

 the gneiss, schists, felsites. or Alwar quartzites. 



AVith the aid of the new maps of Kumaun, Mr. Theobald explored 

 the belt of tertiary rocks at the base of the mountains between the 

 Ganges and the Kali, in continuation of the work done several years 

 previously to the west of the Ganges. 



Mr. Wynne, besides making a reconnaissance of the ground far to 

 the north between Kohat and Thai on the Kuram, accomplished the 



