A. B. Wynne—Paleozoice Rocks of the N. Punjab. 318 
tion of laterite in any region would, if this view be correct, 
depend; (1) on the solubility of the basal rock; (2) on the 
proportion of contained iron; (8) on the fertility of the soil formed 
by its disintegration; and (4)—very largely—on the climate of 
the region. 
In view of the unrivalled opportunities of the Indian geologists 
for testing not only the value of this suggestion, but the validity of 
that recognized principle in the genesis of iron ores on which it is 
based, it will be needless to discuss the applicability of the 
hypothesis at length. Suffice it to remind extra-Indian geologists 
that. at least those of the above-named conditions were decidedly 
favourable to the formation of the laterite. 1. The dolerites and 
other rocks do not seem to be unusually soluble, though sufficiently 
so for the requirements of the hypothesis. 2. The proportion of 
iron in the whole series of Indian rocks is very large—astonishingly 
so, to an American geologist. The general association of carbon- 
aceous and ferruginous deposits throughout the series is quite 
remarkable, and, of course, makes for the hypothesis. 38. The 
disintegrated rocks, notably the traps, form a soil of marked fertility ; 
and abundant plant-remains attest equal fertility during Mesozoic 
and Tertiary ages. The comparative poverty of the existing flora 
is largely due to annual burnings, and to the porosity of the lateritic 
soil; but even in recent times pisolitic nodules of iron have accu- 
mulated abundantly in the alluvium of Bengal and Behar beneath 
the jungles of the Ganges and the Hoogly. 4. The climate to-day 
fosters luxuriant vegetal development, and it must have been still 
more auspicious during the mild seasons of the early Tertiary. 
There is evidence in the recent accumulation of reh, as well as in 
the distribution of existing organisms, that in late geological times 
India enjoyed a moister climate than that of to-day—precisely such 
a climate, in fact, as would follow the clothing of plateau and 
valley with such a mantle of vegetation as to-day exists in the 
Madupur jungle. The roots and perhaps sometimes the trunks of 
the forest trees of that epoch seem to have left their impress in the 
ferruginous soil, just as their homologues in the Mississippi valley 
are preserved in the lower till. 
VI.—On tHe Distrispution AND IDENTIFICATION OF THE PALMOZOIC 
Rocks oF THE NorTHERN PuNJAB. 
By A. B. Wynne, F.G.S., etc. 
PECULATION having been rather freely applied to the iden- 
tification of these rocks, I beg to offer a few notes upon the 
subject, the facts regarding which I have described in a paper already 
published. 
It will be as well at first to indicate briefly where the rocks 
referred to are situated. 
On the map accompanying the Indian Geological Survey Manual, 
the Carboniferous and Silurian formations are shown to be largely 
developed in the Himalayas, the former prominently in the interior 
1 Records Geol. Surv. Ind. vol. xii. part 2, and Map. 
