CHAPTER II. 



DISTRIBUTION OF ROCKS. 



Section IV. — Metamorphic Series. 



Metamorphic rocks occur nowhere within the field, but they form the 

 contact series along the eastern boundary, from Pohi to Moharli, and 

 from Mahadwari onward to the south. The third barrier in the Godavari 

 navigation scheme, which commences at Khirmiri on the Wardha, is due 

 to their exposure in the river bed. 



The valuable deposits of iron ore, which exist in the Chanda district, 

 occur in these rocks. 



Section V. — Vindhyan Series. 



Next in ascending order, and resting unconformably upon the 

 metamorphics, are the Vindhyans. They consist of sandstones and semi- 

 quartzites, shales and limestones, and occur in this order, the shales 

 being also intercalated with the limstones. 



They came but slightly under my observation, and I am not able to 

 speak authoritatively as to the exact geological horizon they ought to 

 occupy; but they are supposed to represent the lower division of the 

 series which has been traced through Raipur and the upper courses of the 

 Mahanadi into close proximity with them. 



It is not quite clear whether all the sandstones of this area which are 

 included under the head of Vindyans ought to be classed with the lime- 

 stones and shales as constituting a connected series, or whether they ought 

 not to be elevated to the dignity of a separate and, perhaps, younger for- 

 mation ; and until they are more closely examined, the doubt cannot be 

 set at rest. A noticeable feature is the peculiarity of their distribution, 

 the limestones and shales being confined almost entirely to the west or 

 right side of the Wardha, and being seldom seen in contact with the 



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