288 NOTE ON THE LA.TEUITE OF OEISSA. 



of country, so impregnate the rocks, that they contain at times no less 

 than 24 per cent of iron,* or nearly 35 per cent of the peroxide ? But 

 even assuming this to be the fact, the only source of the iron must be 

 ferruginous watersf covering the country, and in that case, in places 

 where the detrital deposit was thin or wanting, the clay beneath would 

 only be more strongly impregnated with iron. But so far is this from 

 being the case, tnat, where Laterite is thin or only slightly ferruginous, 

 the clay appears to be nearly or entirely destitute of iron beneath, and 

 wherever the latter appears without the former, there is evidence of a 

 denuding action having removed the Lateiite. 



The following section, from a well which was being sunk at Gerin- 

 gapatna, a village not far south of Chandkar on the Cuttack and Gan jam 

 road, illustrates the poverty of the ferruginous clay, where Laterite is 

 only slightly developed. 



Surface soil, 



Ferruginous gravel, (Laterite of the sandy form and poor in 

 iron,) • • 



Ferruginous clay (Lithomarge), ... 



Variegated clay, bluish grey with red spots, containing pieces 

 of decomposed gneiss, and evidently the result of the alteration 

 of that rock, 12 



In the neighbourhood, where the Laterite was of the ordinary thick- 

 ness and coherence, the clay beneath was highly ferruginous to deptlis 

 of 15 feet or more. 



* Laterite from Daltola, Cuttack, gave 24'5 per cent, of iron. 



Ditto from Kattiwar, W. India, gave 22'8 ditto ditto. 



Ditto from Tanjore, S. India, gave 23'4 ditto ditto. 



t If from any other source, such as' mineral .■-priiigs, it is incredible that the deposit 

 should be similar over any considerable area. 



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