182 Reviews — Vrede)iburg's Summary of the Geology of India. 



Lower Carboniferous and Devonian. 



Silurian, Cambrian, and Pre-Cambrian. 



Oldest Sediments. 



Eundamental Gneiss or Arcbsean. 

 In consequence of splitting the Miocene and Carboniferous formations 

 under the above arrangement a word of explanation is necessary. For 

 instance, he observes that there may be no difficulty in deciding whether 

 a particular bed is newer or older than the Middle Miocene, or than 

 the Middle Carboniferous, yet great uncertainty remains, in the lirst 

 instance, as to whether certain strata in the Siwaliks are to be referred 

 to the Upper Miocene or the Pliocene, and in the second case whether 

 portions of the Lower Gondwana should be referred to the Upper 

 Carboniferous or the Permian. Hence the use of local terms to include 

 a geological group is held to be justified. 



The several systems enumerated in the above list are then dealt 

 with in reversed order, commencing with the Archaean so largely 

 developed in peninsular India. He considers the Central Gneiss of 

 the Himalaya to be in part at least of Archaean age. Much has been 

 done of late years in the petrology of this group of rocks. Amongst 

 other matters the author refers to certain enstatite-bearing rocks in 

 the south-east of the peninsula, the types of which most nearly 

 resemble a granite in composition, as having been called 'charaockites' 

 by Holland because the tombstone of Job Charnock, the alleged 

 founder of Calcutta, consists of a slab of that rock. 



We could scarcely venture on the present occasion to follow 

 Mr. Vredenburg in his brief but lucid descriptions of the several 

 sedimentary series, whether fossiliforous or the contrary. There is 

 a great amount of useful information conveyed within the scope of 

 a very few pages. A glance at the geological history of India during 

 the period usually known as Permo-Carboniferous (i.e. Upper 

 Carboniferous) must suffice, for this deals with a subject to which 

 special importance is attached. 



The author commences bj' referring to the extensive orogenic 

 upheaval in many parts of the globe at a period which he places 

 towards the end of the Middle Carboniferous. Thus the junction 

 with the Upper Carboniferous is usually indicated by an unconformity- 

 conglomerate, which often exhibits peculiar characters that have been 

 regarded as glacial. After indulging in a certain amount of speculation 

 in connection with this well-marked phenomenon in the history of our 

 planet, he proceeds to deal with (r/) the Gondwana facies, and (h) the 

 Marine facies. We need not in this case follow the author into 

 details of the Gondwana system, but it is interesting to note that in 

 the Himalayan region typical Gondwanas are said to be found in the 

 neighbourhood of Darjeeling and in Bhotan. 



There is, however, on p. 40 a statement in connection with the 

 peninsular Gondwanas to which some exception might be taken. " It 

 will be seen," says the author, "that the age of the Coal-measures of 

 India differs considerably from that of the Coal-measures of (xreat 

 Britain and the Franco-BeJyian basin, all of which are Lower or Middle 

 Carhoniferous in aye'''' (the italics are ours). We wonder whence he 

 derives his authority for this statement, since almost any textbook 



