KAMTHI. 



overlapping them extensively ; but it is nevertheless a member of the 

 Gondwana series, and represents in time the upper division of the Damuda 

 series, and possibly also a portion of the Panchet formation of Bengal. 

 It is the most extensively-developed series in the field, covering a large 

 unbroken area of several hundred square miles on the left side of the 

 Wardha. It is devoid of coal, but connected with its occurrence is the 

 important inference that coal may be found at a moderate depth beneath 

 its lowest strata. 



The name Kamthi was provisionally given to this series by Mr. 

 Blanford, when examining it in the neighbourhood of the military sta- 

 tion of Kamthi, near Nagpur. There was at first no intention of retain- 

 ing the name, it being thought that evidence might be accumulated to 

 identify the rocks so designated, as members of the groups already es- 

 tablished in Bengal. But though the fossil plants in the Kamthi beds 

 connect them with the Damudas, the mineral character of the Kamthis 

 is at variance with that of both the Ironstone shales, and the Raniganj 

 groups. There is a similarity in the aspect of some of the clays in' the 

 Kamthis, to those of the Panchet series in the Raniganj field, but there 

 the likeness ends. The name therefore has been continued, and it indi- 

 cates rocks possessing a distinctive mineral character. 



The rocks are sandstones, clays, and conglomerates, of which 

 the sandstones and shales form the bulk of the 



Descriptive summary 

 • of rocks. 



series. 



The sandstones exhibit almost every shade of color, and almost every 

 degree of texture. Many of them are highly ferruginous, others calca- 

 reous, and a few have manganese distributed through them. At the 

 base of the series, the sandstones are usually coarse-grained, porous and 

 friable, and slightly yellow, reddish-brown, or grey 

 in color. The porosity which may be an aboriginal 

 character is an important distinctive feature, as it is not seen in the 

 sandstones of the Barakar group. Amongst the indications that influence 



( 67 ) 



