100 INTRODUCTORY NOTE. 



Id drawing up the following report on this district at large, he has, of 

 course, had free access to the labours of his colleagues, Mr. William 

 Theobald, Junior, his brother, and myself, and has combined the results 

 of all ; but to his own exertions are due by far the larger portion of the 

 valuable facts detailed below. 



It is satisfactory to find that the more recent, and more extended 

 examination of the district by Mr. Medlicott, has resulted in fully 

 confirming the general outline given in 1856 of the principal facts in its 

 Geological structure. In some respects the rough sketch I then hastily 

 gave, has been corrected, and many important features have been filled in ; 

 but on the whole, these changes have been far more in the nature of 

 additions, than of alteration. The great groups of the Mahadeva and 

 Damuda on the one hand, then first announced and established by myself, 

 and of the Vindhyan on the other, which the brothers Medlicott had 

 separated during the previous year, remain now, as then, the key to the 

 structure of the country : this being the earliest attempt made to reduce 

 to order the confused mass of sandstones, shales, &c, which had previ- 

 ously been all jumbled into one great heap of anomalies. 



The sectional diagrams given in illustration are chiefly from Mr. 

 Medlicott's note book ; the sketches showing the general features, irom 

 my own. 



T. OLDHAM, 

 Supdt. of Geological Survey of India. 



