300 Notes on the South Mahratta Country, fyc. [No. 160. 



weathered nodules of the rocks from which it was derived. I have also 

 seen laterite resting on limestone without a traceable particle of lime in 

 its composition. This could not have been limestone weathered in situ. 



The fact of one hill being capped with laterite, and its neighbour 

 being left bare, is a circumstance also militating against another theory 

 adopted by some Indian geologists, viz. that of its alluvial origin from 

 causes now existing. It is impossible to see the laterite capping in 

 tabular strata, as at Beder, hills of trappean or hypogene rocks separat- 

 ed by vallies, wide plains or elevations, in which nothing but the latter 

 rocks are seen, without coming to the conclusion that the beds of 

 laterite were once continuous over these spaces, and stripped off by 

 waters of which nothing but the trace of denudation now remains. 

 Natural sections often remind one forcibly of that striking instance of 

 denudation of the red sandstone, on the N. W. coast of Ross-shire 

 given by McCulloch in his Western Isles, Vol. II. p. 93, pi. 31, fig. 4. 



The annexed diagram is a section taken on the W. coast, between 

 Honawer and Sedashegur. 



The rarely fossiliferous character of this iron clay or ferruginous clay, 

 as it has been called, which has puzzled some geologists,and inclined 

 others to the theory of its volcanic origin, may be in some measure at- 

 tributed to its highly ferriferous nature, often approaching that of an 

 ore of iron. It is a fact, and, as Lyell observes, (Geol. Vol. II. p. 102,) 

 one not yet accounted for, that scarcely any fossil remains are preserved 

 in stratified rocks in which this oxide of iron (derived from the disin- 

 tegration of hornblende or mica) abounds ; and when we find fossils in 

 the new or old red sandstone in England, it is in the grey and usually 

 calcareous beds that they occur. 



I have often observed, particularly in the W. Ghauts, and on the Ma- 

 labar and Concan coasts, where the rains fall heaviest, that the granitic, 

 hypogene and trappean rocks containing most iron, weather into fer- 

 ruginous and coloured clays that sometimes, lithologically speaking, 

 resemble laterite, and these when that rock is near, cause the appearance 

 of their passing into it. I have also observed beds of considerable mag- 

 nitude of an impure oxide of iron in gneiss and hornblende, sometimes 

 cellular and pisiform (and from which much of the iron in laterite has 

 doubtless been derived) ; but when we look up from the microscopic view 

 afforded by these slowly weathering blocks of rock and beds of ore in situ, 



