iS JONES : SOUTHERN COAL-FIELDS OF sATPURA GONDWANA BASIN. 



south. There is no evidence to show that the Talchirs ever extended 

 far to the south of their present limit, and no traces of them have been 

 found at any distance in that direction, though, taking into considera- 

 tion the fact, that there has been a considerable rise to the south of 

 the line of faulting inside the field, there is a possibility that they did 

 so extend and have been subsequently denuded away. 



The Talchirs consist of boulder beds to a very large extent, the 



shales almost invariably containing at least a 

 Petrology. 



few boulders and being often crowded with 



them, and the sandstones also frequently to a high point contain some 

 boulders. The boulders are generally of gneiss and schist which 

 might have been derived from the metamorphics in the vicinity, but 

 in many cases there are also boulders of a much more variable charac- 

 ter than anything exposed near, and there are occasionally, as 

 near Pandra and Chordongri (E. Lon. 78 7'), boulders of sand- 

 stone resembling some of the Vindhyan sandstones, which must have 

 come from a distance ; and as there is nothing particularly distinctive 

 about the metamorphic rocks, the whole may have travelled from a 

 distance. 



The sandstones and shales have the greenish tinge peculiar to the 

 Talchirs, and, except for the greater frequency of boulders, they 

 resemble the same rocks as described in other fields. 



The dip is as a rule northerly to north-westerly at low angles, not 

 unusually exceeding io°, though in places it is as much as 30 , and 

 towards the south or east. 



Mr. H. B. Medlicott has estimated 1 the possible thickness of the 



Thickness of the Tal- Talchirs in a portion of the Shahpur field as 



chirs# over 2,000 feet of accumulated time-thickness. 2 



This appears to be the portion of the whole area where they attain 



their greatest thickness. 



To the west they continue to have a considerable thickness almost 



1 Rec, Geol. Surv. India, VIII, 80. 



3 Mem., Geol. Surv. India, X, p. 140, note. 



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