AilAVALLI SYSTEM. 53 



by Adams and Barlow is, however, of so striking a nature that 

 it may be allowable to apply the explanations offered by the above 

 authors as being at least probable in this case. 



They consider (loc. cit., p. 157) that the amphibolites of the 

 llaliburton and Bancroft districts " include rocks of very diverse 

 origin, but which, under the intense action of the metamorphic 

 processes to which they have been subjected, have acquired a certain 

 and often striking community of character and composition." 



That some of them are intrusive in their nature is considered 

 proved by their cutting across the edges of the beds of crystalline 

 limestone. On the other hand the authors say, p. 10G : — 



'"It is, for instance, quite possible that the amphibolite may be derived in 



pari from therccrystallisation of volcanic aShes thrown out from volcanic vents. . . ." 



The sedimentary origin of the ' feather ' amphibolite is said 

 (p. 1G9) to be most clearly shown by passages into areas of much 

 less altered limestones which in many cases arc blue in colour. 



On the whole I should imagine that Adams and Barlow would 

 have interpreted such rocks as these at Kherod as having had a 

 metamorphic origin. Consider the following remarks, p. 158 : — 



" The several bands are sharp and well-defined, but differ in colour, owing to 

 the darker constituents being relatively more abundant in certain of them. In 

 certain cases there is also a difference in size of the grains of the severab bands. 

 This parallelism gives to the minerals in the rock the appearance of a bedded deposit 

 which it probably is in many cases, especially when it is interbedded with thin 

 layers of limestone " 



(6) Mundeti Series. 



Between the group of more or less connected members of the 



Aravalli system so far described (namely the 



Anu-aiiis 1 ' fn " n "^ oak-gneiss, biotite-gneiss and amphibolite- 



limestone, together with the aplite veins 

 intrusive in the two former) and the Mundeti series whose descrip- 

 tion will now follow^, there exists a. gap. S or 9 miles wide, where 

 only alluvium with no solid rock is met with. Hence the Mundeti 

 series is not linked up by actual exposures with any member of the 

 previously described Aravallis. 



Furthermore, this series is, at least superficially, different in 



Comparisons with the character, — sufficiently different in fact to 



Cftlo-gneisa and Kherod bear the new and local name of the Mundeti 



series ; and, as in the case of the Kherod 



