124 CRETACEOUS ROCKS OF S. INDIA. [PaRT II. § 1. 



the whole Southern part of the formation. The banks of shingle near 

 Thapaye and Jewalapoor indicate the existence of 



Shingle deposits. 



beaches at these points, during the early part of the 

 Trichinopoly epoch, which were subsequently buried beneath sands and 

 gravels, as submergence progressed. That to the North of Cullygoody is 

 probably of later date, and may have belonged either to the close of the 

 Trichinopoly period, or the commencement of that of the Arrialoor group. 



The Trichinopoly group is, as we have seen, restricted in extent. 

 There is no reason to believe that subsidence ever progressed to such a 



Land area of Ti' hin - P^ii^t as to submerge the Thutchuncoorchy ridge 

 poly period. during its formation, for while there is no evi- 



dence of any denudation of the Trichinopoly beds previous to the com- 

 mencement of the Arrialoor period, the de]30sits of the latter overlap the 

 former at the extremity of this ridge, and contain pebbles of the gneiss 

 and granite of which it is formed. At their Northern extremity the 

 Trichinopoly beds are obscured by superficial deposits, so that we cannot 

 ascertain the features of the Arrialoor overlap in that du-ection, but from 

 the strike of the bedding, it is very clear that the Trichinopoly deposits 

 diminish rapidly from South to North, and it is very probable that the 

 bank of sediment never extended in any great thickness much beyond 

 the actual Northern extremity of the Trichinopoly out-crop. 



The inclination of the bedding in the Northern and more regularly 

 deposited part of the group is lower than that of the Ootatoor group, 

 averaging 6°, and nowhere exceeding 15°, except when the lowest beds 

 rest on denuded slopes of the Ootatoor beds, as near Shutanure. In 

 some of the local unconformities of the irregular deposits to the South I 

 have observed dips as high as 25°. 



With respect to the distribution of the fossils, it is noticeable that but 



very few occur in the irregularly deposited part of 

 Distribution of fossUs. 



the group, large areas bemg totally unfossiliferous. 



Not a single specimen of Ammonite has been met witli in this part of 



