44 CRETACEOUS ROCKS OF S. I^DIA. [PaRT II. § 1. 



Hillanum, Astarte Planissiyna, and Turritella Soiuerbii, an asso- 

 ciation Avliicli leaves Utile doubt of tlieir Trichinopoly age, whether 

 tliey be part of a little outlier, or liave been brought to the spot 

 by the natives. 



A little to the north of Kauray the plant-beds are again overlapped 



by the Ootatoor Group, and do not re-appear 

 Plcant-beds at Varaga- 

 paudy. till just beyond the village of Varagapaudy. 



A thick mass of soft brown sandy shale here occurs at the base 



of the group, and is well seen in the bed of the little stream to 



the North of the village. The shale is thoroughly reticulated with 



infiltrated kunkur, which, in the bed of the stream, stands out on 



the surface in masses like a tangled growth of Madrepore. This 



only occurs close to the bottom of the beds, 



Kunkur. 



and is evidently of ulterior formation ; it was 



probably deposited by waters infiltered from the overlying calcare- 

 ous strata of the Ootatoor Group, which, being checked in their doAvn- 

 ward course by the less pervious gneiss, have thus saturated the 

 lower beds of the plant shales, and deposited the calcareous matter 

 in solution in the micaceous substance of the shales. A similar 

 phenomenon is seen in another little nullah about a mile further 

 to the north, where a bed of grey micaceous shale is seen resting 

 on the gneiss, and in this latter case the deposit has taken place in 

 the joint-like fissures, (probably due to shrinking) by which the mass 

 is divided. They present a curious appearance, where, in the bed 

 of the nullah, the soft shale has been eroded, leaving a system of 

 intersecting partitions standing out like boxes on the surface. Many 

 acres of the surface of the ground to the west of Coodicaud is 

 thickly covered with kunkur, probably from denuded beds of the 

 plant-bearing group ; judging from the sections seen in the banks of 

 the nullahs, the deposit must average not less than four or five 

 feet in thickness. 



