94 Geological Features [no. J, new series, 
in syenitic granite, or greenstone, is prevalent, while to the south 
of it mica, combined with quartz and felspar forming the common 
or porphyritic granite, is equally prevalent. 
We have now arrived in our notices of the country at the eastern 
part of the Trichinopoly District, which is traversed by that re- 
markable bed of fossil-shells already referred to, sometimes called 
the Ootatoor marble. In the tour mentioned above, this region 
was visited, and I proceed now to state a few particulars in regard 
to it. 
In the vicinity of Ootatoor, the syenitic granite containing gar- 
nets is very abundant, it crops out and lies on the surface in flat 
masses and huge blocks ; and rises into h'llls and mountains im- 
bedding in some places the blue or oolitic quartz, fine specimens of 
jade, crocidolite, and a black curiously crystalline carbonate of lime 
and small pieces of iron. 
About half a mile east of the Travellers' bungalow, the granite 
disappears from the surface, or remains only in small quantities 
and scattered in disintegrating fragments. The prospect from this 
place to the north, east and south is that of a great plain extend- 
ing in vast wave like undulations as far as the eye can reach. 
The soil is a dark loam containing magnesia and lime evidently 
formed from the disintegration of the rock on or beneath its sur- 
face. Small pieces of red irony crystalline limestone as also pieces 
of the marble full of small white shells of the multilocular class 
called the turrilite are found here. 
In the rolling surface of this plain, there is a fair opportunity, 
considering the loose and earthy nature of the soil, for the denud- 
ing effects of the water, hence we see many of those ridges worn 
into banks and mound-like and deep ravines by the torrents. One 
of these, about a mile east of the bungalow is well marked. The 
ravine is about 58 feet deep and lays bare the surrounding strata 
to a considerable extent. The upper stratum on the western side 
is a marl or earthy limestone and occupies a large portion of the 
surface ; the next stratum below appeared to be an iron sandstone, 
slightly resembling laterite yet regularly stratified, and of a red- 
dish brown color, evidently containing a considerable quantity of 
