TRANSACTIONS OIT, SECTION C. 639 



the western half, whilst not a trnce has heen found around the eastern half, except 

 far to the eastward. In later Tertiary times the sea that ocfcupied the Indus 

 valley appears to have greatly decreased, and still further diminution of the 

 marine area took place during the Pliocene epoch. As several species of land 

 mammalia in the Pliocene Siwaliks are also found in' Guzerat, it is manifest that 

 land commimication must have existed between the two areas. 



All that is known of the Post-pliocene and recent deposits in the Indo-Gangetic 

 plain leads to the same conclusion ; no marine bed has yet been detected in them. 

 Only a few borings have been made : but in one to a depth of 701 feet, at Ura- 

 bala ; in another 431 feet deep, at Bhiwani in Hissar (Punjab), and in a third 574 

 feet deep, at Sabzallsot in the Derajat, west of the Indus, no marine remains were 

 discovered, and the beds traversed appeared to be all river-deposits. Still more ex- 

 traordinary is the circumstance that the boring made at FortWilliam in Calcutta, 

 to a depth of 481 feet below the surface, or 400 below the sea-level, passed through 

 not a single undoubted marine deposit, whilst peat, freshwater shells, and mamma- 

 lian bones were found, some of them at almost the greatest depths reached. 



The whole of the negative evidence, and some direct evidence, is, therefore, 

 opposed to the idea of the Gangetic plain having ever been occupied by the sea. 

 The tract is evidently an area of depression filled up to above the sea-level, in all 

 probability, throughout a long geological range of time, by the detritus from the 

 surrounding mountains, and to a smaller extent from the hill tracts to the south- 

 ward. 



10. Tlie Gold Fields, and the Quartz-outcrops of Soutliern India. By 

 William King, Deputy Superintendent (for Madras), Oeological Survey 

 of India. 



This paper was a resume of the knowledge ascertained through the author's 

 original survey of the Wainad gold field in 1874, and by the later surveys and 

 examinations of others : also in his examination of the Travancore and other areas 

 in the beginning of this year. 



The geographical distribution of the gold areas is briefly treated of as being 

 at Mangapet, on the Godavari river, near Dumhal, in the South Mahratta country, 

 near Kolar, in Mysore, at Salem, in part of the Travancore State, and in the Nil- 

 giri and Malabar country; and these are then reduced to the more important 

 fields of Malabar (including Wainad and the Nilgiris) and Mysore. 



Next follows a description of the rocks (Gneissic Series) of these two areas ; 

 and the extent, mode of occurrence, and constitution of the quartz-reefs traversino- 

 them. These gneisses are striking, in Mysore, northwards and southwards, and in 

 Malabar north-east and south-west; while the reefs in both cases are runnino- 

 north-north-west to south-south-east, or thereabout, and are considered by the 

 author to occupy the widened-out fissures of meridional jointing". 



The reefs of Wainad are developed to a remarkable extent over a very large 

 area of country ; but their auriferousness is only displayed over a portion of this 

 (mainly in south-east Wainad and in the adjacent low-country of Malabar), in a 

 generally east-and-west belt, the reefs outside of this being fewer and only very 

 locally auriferous. The leaders or offshoots of the reefs in this belt are strongly 

 and numerously developed ; and they and the 'casing' are rich in gold. It is 

 these adjuncts of the reefs, and not the reefs themselves, which have been so ex- 

 tensively worked by the ancient miners. On the other hand, the reefs, as far as is 

 known, do not as yet show any continued steadiness in their auriferousness, but 

 may be said to be capriciously permeated with the precious metal. The gold of 

 the reefs is pale-coloured and of about the ' touch' of standard gold; that of the 

 'leaders' and 'casing' is yellow gold and of superior quality. 



The apparent distribution of the gold in a generally east-and-west belt over a 

 country whose rocks are striking north-east and' south-west, and the quartz-reefs of 

 which are running north-north-west to south-south-east, and far beyond the limits 

 of this belt, leads the author to speculate on a possible deposition of the gold 

 subsequent to the formation of the reefs. 



