122 CRETACEOUS ROCKS OF S. IXIJIA. [PaRT II. § 1, 



about a mile to the South-east of Vapoor. I coiald not ascertain at what point the Trichinopoly 

 beds finally disappear, but in a little section to the East of Olapaudy, described at 

 page 95, (Fig. 10, ante,) the Arrialoor beds characterised by several peculiar fossils are 

 seen resting on those of the Ootatoor group, the Trichinopoly beds having been over- 

 lapped in the interval. 



Deductions from the foregoing. 



We have seen in a foregoing chapter that at the close of the Ootatoor 

 period a disturbance, chiefly affecting the Granitic band of Thutchun- 



Disturbance and eleva- coorchv, elevated that regfion "with its overlyinsr 



tion of Thutchuncooi-chy •' ^ "^ ° 



Granitic ridge. deposit, and thus, during the succeeding Trichino- 



poly period, the coast line, which, in Ootatoor times, conformed approxi- 

 mately to the outline of the hilly region, was diverted to the Eastward, 

 enclosing a bay-shaped depression, in which were subsequently deposited 

 the beds of the Trichinopoly group. 



It is probable that in addition to the Thutchuncoorchy ridge, a large 

 part of the Ootatoor beds to the North, or on the downthrow side of the 



line of disturbance, were, prior to the formation of 



Elevation of Ootatoor ,,„,.,. , , i^jx i. 



group wOT«sse, and subse- the irichinopoJy group, also elevated to sucn 

 ^^^^ ' an extent as exposed them to considerable denu- 



dation. That such was the case is indicated both by the striking uncon- 

 formity of the two groups at Ilpagoody (page 119) and Seraganoor, and 

 also by the strong presumptive evidence, that the Trichinopoly group was 

 at one time continuous over the present surface of the Ootatoor beds 

 between Tripatoor or Seraganoor and Garoodamungalum. Now I have 

 endeavored to show that the present dip of the Ootatoor group 

 to the Eastward is mainly, if not wholly, due to its mode of depo- 

 sition on the edge of a sub-marine bank. The surface of the Ootatoors 

 as now existing, is formed as we have seen of the out-crop of these 

 inclined beds, and is therefore a surface of denudation, and the position 

 of the outliers of the Trichinopoly group is such, that we can scarcely 

 conceive that that part of the Ootatoor group lying between those 

 outliers and the main formation, can have undergone any great amount 



