Chap. IX.] arrialoor group — verdachellum area. 14;j 



Cretaceous rocks have been exposed by subsequent denudation, is at once 



apparent on glancing at the map,* and it is probably, in consequence of 



their lower level, that, as in Trichinopoly, the Cretaceous rocks are in great 



part covered with regur, which conceals the greater part of their out-crop. 



They now occupy a strip of country from 2 to 3 miles across, extending 



„ , , ^ ^ from the bank of the Mani Mukta to that of tlie 



Much concealed by 



i'^S^- Guddalura, but they are only exposed at one or two 



places, the principal of which is Messrs. Kaye and CuolifFe's original fossil 



locality in the neighbourhood of Pulliyur or Paroor. Thanks, however, to 



the reduction of the land rental within the last few years, many wells 



have been sunk in different parts of the area, for the irrigation of the 



hitherto waste lands, and these have disclosed the presence of Cretaceous 



rocks over a large area, where it would otherwise have been difficult fo 



establish the fact of their occurrence. They present themselves for the 



most part as a soft sand, or a sandy clay, with casts 

 Lithological characters. 



of small fossils, and there appears to be a passage 

 from coarser to finer materials, as we proceed from South to I^orth. The 

 bottom bed is generally calcareous, and sometimes forms a tough arena- 

 ceous limestone, at other times it occurs in the form of thin calcareous 

 shales. It is also sometimes conglomeratic, but the pebbles are few and 

 small, and nowhere is there anything like a coarse conglomerate such as 

 occurs at base of the Arrialoor group in the South of Trichinopoly. The 

 beds appear to have been deposited in a tranquil sea, free from shifting 

 currents, and they have undergone little, if any, subsequent disturbance. 

 The beds of arenaceous limestone which, as I have above stated, occur 

 Fossiliferous beds of ^^ ^^^ ^^^^ of the group, are well seen in a nullah 

 ^^' about a mile to the South of Pulliyur (Paroor), a 



village 5 miles North-west from Verdachellum. About 12 or 15 feet of a 



* That is the corrected map. Owing to some strange blunder a space of about 20 square 

 miles to the North-west of Verdachellum is, in the Atlas Map, only correct in the names of 

 some of the villages being enumerated. They are all transposed from 3 to 5 miles from their 

 correct position, and the large stream takes an impossible com'se over some of the highest ground 

 in the neighbourhood : even the road to Oolunderpet is fully a mile to the West of its proper place, 



T 



