282 



GEOLOGICAL SURVEY 



of the vast country, by far the greater part of which was 

 geologically a terra incognita. 



The survey of the Madras Presidency was taken up early 

 in 1857, when Mr. H. F. Blanford was deputed with Messrs. 

 CM. Oldham, W. King, and H. Geoghegan 3 to examine 

 imprimis the cretaceous rocks known to exist in Trichinopoly 

 and South Arcot, in order to obtain, if possible, a fixed geolo- 

 gical and palseontological horizon, a datum level as it were, to 

 which to refer the various sedimentary rocks that might be 

 met with as the survey progressed. When the Madras party 

 of the Geological Survey entered upon its work, the amount of 

 geological information they found ready to hand concerning 

 Southern India was considerable, but much of it was of little 

 or no value. A number of writers had, it is true, given their 

 views to the public, but most of them related only to very 

 circumscribed tracts, or if like the geological summaries of 

 Calder, Newbold, and Carter 4 they treated of the general geo- 

 logical structure of the peninsula, they were necessarily mere 

 outlines of the subject, many large tracts of country being 

 quite unknown to geologists and others known only by rapid 

 traverses. No tract of any size had been mapped or examined 

 closely and systematically. Greenough's Geological Map 

 of India, the only one which had then appeared, though 

 worthy of much praise as a most laborious compilation, was of 

 little practical use, as it abounded in serious errors both 

 geological and geographical. The most important and 

 extensive series of geological facts then known was that con- 

 tained in Captain Newbold's 5 Summary — a very able work 



3 Mr. Geoghegan died of sunstroke in 1858, and his place was taken by the 

 author. 



* Published respectively in 1833 Asiatic Researches, vol. xviii, 1844-50; 

 Journal, Royal Asiatic Society, vols, viii, ix, and xii, and 1854; Journals 

 Bombay Royal Asiatic Society, vol. v, and reprinted in Geological Paper, 

 on Western India in 1857. 



6 Captain Newbold was attached to the Quartermaster -General's Depart- 

 ment of the Madras Army. 



