NERBUDDA DISTRICT. 219 



arrangement, so well known as a peculiarity of these rocks every 

 where. 



The ground rises from the lowest levels in terraces, which correspond 

 in height on the different hills, themselves all flat-topped save only the 

 highest, where frequently a little boss of the last trap flow has been 

 left by the denuding agents. 



Far to the east again the trap becomes the prevailing rock of the 

 country (see map) and the same features are developed. The new road 



Chaneli and Richera frora Chindwarra station to Nursingpur, passes 

 country. oyer ^is tra p coun t rVj and its course lies near 



the foot of Chaneli hill, one of the highest of the country. From its sum- 

 mit a commanding view is obtained; Deodungri hill, 20 miles to the west, 

 Korekera hill, a greater distance still to the north-west, and Richera hill 

 to the north, with many minor eminences, irregular ridges, and branching 

 spurs, form a very striking landscape, in every portion of which the 

 terraced outline of the trap rocks is distinctly marked. 



When examined in detail, this structure is seen to be due to distinct 



flows. Descending from Chaneli, or any other of 

 The flows. 



the principal hills, a section across several of these 



flows is obtained, and each one may generally be distinguished from that 



above, and that below it, by some well defined mineral characters ; but 



these characters are seldom found constant in any one bed or flow for 



any considerable horizontal distance if we follow them in that direction. 



The most common varieties, lithologically and mineralogically con- 



Lithology of the trap, sidered are as follows : — 



(a) Granular sub-crystalline diorite often porphyritic, with crystals 

 of felspar. 



(b) A hard heavy very ferruginous basaltic trap. 



(c) A pale green crumbling earthy rock. 



This last (c) is specially characterized by an exfoliating (or onion- 

 like) structure, also frequently seen in (b) but never in («). (b) and (c) 



