120 CRETACEOUS ROCKS OF S. IXDlA. [PaRT II. § 1. 



beyond the occasional out-crop of a band of limestone, which' is either unfossiKferous or 

 contains a few Cheninitzias and fragments of fossil wood, the former characterising the bed 

 as of Trichinopoly age, and distinguishing it from the similar and parallel bands of limestone 

 which here occur in the apper part of the Ootatoor group. On the brow of the ridge 

 between Kolokaunuttom and Shutanure, fossils re-appear in greater abundance, in the 

 limestone, a conspicuous band of which marks the base of the group ( Fig. 15) as 



TJnconformity of groups. ^^r as the broken ground represented in the figure. Here ita 



llpagoody. face is fully exposed ; and it is seen to twist round almost at a 



right angle, and rest on the denuded edges of the Ootatoor beds {see Fig 15). The 

 local denudation of the latter beds at this spot, previous to the deposition of the 

 Trichinopoly gtoup, is noticeable, when contrasted with their general conformity in strike, 

 and frequently in dip also, elsewhere on the line of junction. As may be seen in the 

 figure, the Ootatoor beds have been so denuded as to leave a steep bank upon which 

 the Trichinopoly beds rest, at an angle of from 20° to 30° ; a dip, however, which does not 

 obtain except in the lowest beds. A few yards off the beds are nearly horizontal. The 

 phenomena of this unconformity bear so much resemblance to those of a fault, that were 

 it not for the thorough exposure of the beds in the broken ground, and the absence of 

 any signs of disturbance in the Ootatoor beds, I should have been inclined to attribute 

 them to this cause, but as it is, there can be no doubt whatever of the real state of things. 

 It seems as if a breach had been made in the bank of the Ootatoor deposits at this point, 

 and that in the gap so formed, and which is about 1 mile in width, Trichinopoly beda 

 had been subsequently quietly deposited. These beds are sands and sandy shales of 



Ehynciionella and Terebra- the usual character, and contain many of the characteristic 

 tula bed. fossils of the group. At one spot South-east of Shutanure Mr. C. 



Oldham found almost the entire mass of the rock made up of Rhynchonellas and a small 

 species of Terebratula. He met with a similar rock also, some miles further North, in the 

 neighbourhood of Andoor. 



To the North of Pelamasey the Trichinopoly beds are veiy uniform in character, and such 

 points as are of interest may be recounted in a few words. Near 



Bottom beds-Pelamasey. ^^^ ^^^^ ^^ ^^^ ^^^^ ^^^^^ ^^ ^^^^ limestone, closely resembling 



that of Garoodamungalum in mineral character and fossil contents, and bands of large calcareous 



concretions, alternate with sandy shales, and form a coEspicuous ridge between Audanoret 



and Coonum. The out-crop of one of these latter bands is seen close to the village of Audanore, 



About 100 feet of shale and sand occur below, and these contain few or no fossils. 



One of the best sections of these bottom beds is seen in the upper part of the nullah between 



Permalpolliam and Moonglepaudy. At a point about North by East of Permalpolliam the bottom 



of the Trichinopolv Group is intersected by the nullah. There is 



Junction of groups— Per- ^ •' ^ i ^ x-l - ^ i •. 



malpoUiam. no great unconformity between the two groups, but the bottom bed 



of the Trichinopolies, an irregular band of sandstone, rest on the eroded surface of the Oota- 

 toors, with the intervention of a thin ferruginous deposit. The lowest bsds are, lithologically, 

 almost undistinguishable from the Ootatoor beds, being in part ochreous shales with gypsum, 

 and some calcareous bands, which dip about 8° to the E. S. E. Higher up the nuUah, where the 

 Umestone bands cross it, the dip rapidly increases to 15° ; but this is quite local, and both to 

 the North and South of the nullah, at the distance of a quarter of a mile, the dip of the lime- 

 stone does not exceed 4°. To the North of the nullah some of the beds are highly conglomeratic, 



