TIECORDS 
OF THE 
GEOLOGICAL SURVEY OF INDIA. 
Part 3.] 1879. [August. 
On the geological featukbs op the nobtheen part op Madera District, the 
P oDEKOTAi State, and the southern parts op the Tanjore and Trichinopolt 
Districts included within the limits op Sheet 80 of the Indian Atlas, 
hj R. Bruce Foote, F.G.S., Geological Survey of India. 
I.—INTRODUCTORY. 
The 'country to be noticed in the following pages belongs partly to the Madura, 
Tanjore and Trichinopoly districts, partly to the native state of Pudu- 
kotai (Poodoocottah) or Tondiman. Topogi'aphically this region may be 
described as a gently undulating inclined plane rising very slowly westward 
from the delta of the Cauvery, or the sea board. It is only in the western 
pai-t that the surface is broken by a few low but steep hills rising in the gneissie 
area, and by the lines of scarj) corresponding generally with the western boun¬ 
dary of the lateritic formations, which occupy by far the greater part of the 
country now under consideration. 
The hydrology of this area is of very simple character, all the drainage 
H di'olog falling in a general south-easterly direction into the 
section of the Bay of Bengal known as Palk’s Bay, by 
eight principal streams. These streams are, with one exception, quite of small 
size, the exception being the Vaigai (Vygah) which drains the central part 
of Madura district. Of the others the two most northerly are really branches of 
the Cauvery proper; they are the Kori-ar (Ooray-aur) and Pamani-ar (Pau- 
maney-aur), the former running parallel with, but a little distance from, the 
western boundary of the southern part of the delta, the latter flowing partly 
just within the delta, and partly within the lateritic area, this latter part of its 
course being apparently of artificial origin. 
The Ikani-dr (Icauney-aur) which falls into the bay to the south-west of 
Adrampatam rises in the Trichinopoly district, close to Illipui, has a course of 
only about fifty miles, and is rather torreht.like in its behaviour in wet seasons. 
