Chap. XII.] soils and superficial deposits. 199 



soils or superficial deposits (including laterite*) rich in iron, richer as 

 a rule than thick sedimentary formations originally derived from the 

 same source, viz., the metamorphic rocks. 



The foregoing remarks on the origin of the regur and sandy soils 

 of Trichinopoly are probably applicable to those of a large part of the 

 Peninsula, but I, for the present, confine myself to the considerations 

 of those which I have personally observed ; the elevation of the Indian 

 Peninsula, evidenced by their extensive occurrence at considerable 

 elevations is a phenomenon of great importance which should be con- 

 sidered in connection with some other facts, the treatment of which is 

 beyond the scope of the present paper. 



* I do not here mean to assert that all laterite is thus formed. Any deposit rich in iron 

 may form a laterite when exposed to the action of the atmosphere, and in Southern Ceylon 

 gneiss decomposed in situ assumes a lateritic structure . 



