Records of the Geological Survey of India. 
[vol. T. 
02 
Many of the agates in the gravel have, a peculiar dark semitransparent look, resembling 
flint. Such do not elsewhere prevail amongst the varieties occurring in the traps. 
Large numbers of the agates in the gravels are fractured. 
In the drift wood, twigs, grass and rubbish deposited at the edge of the river, I found 
the following land and fresh-water shells. The list may be useful, if the sub-recent and 
ploiocone deposits bo hereafter searched for comparison. 
Helix Tranqueharica, Fabr. (the Deccan variety, which is near the shell figured by Reeve 
in the Cone. Icon, as it. vUellim, Ptfr.). 
„ utomus, Fairbank, M. S. (a very minute species of the Macrochlamys type resembling 
If. vitrinoides or one of the European Zoniles in form). 
,, c.rassicostata, Benson. H. fallaciosa, For. 
Sulimus pitlliis,* Gray, 2 or 3 varieties. ]}. camopictus ,* Hutton. 13. Abyssinicus, 
Rupp. (a finely costulated var. B. moussonianus /). 
Pupa (or Can/chiurn ?), sp. 
Achalina Vadalica, Benson. A. brevis, Pffr. A. baTanus,* Bens. 
Planorbis compressus, Bens. : P. sp,,* small: P.coromandelianus, Fabr. 
Melania iuberculata ,* Lam. 
Bythhiia pulehclla? Bens. II. sp. (minute). 
Pahidina melanostoma. 
Unio cwruleus ? Lea, rare : U.favidens *? Bens. 
Covbicula arafa *? Bens.: Pisidium sp. 
Those marked thus* are most abundant. 
The road from Moonghce to Jalna traverses for some distance the gently undulating 
plain, which does not end to the north abruptly -in general, though at Chandalla and 
Bambeora a little escarpment is seen, formed by a hard bed of trap. It is apparently 
perfectly horizontal. The same horizontality is seen in the range of hills near Umbud and 
on the traps around Jalna. If there be any dip it must be a very low one indeed, to south 
or south-east .f 
From Jalna to Loonar the traps appear horizontal. No change whatever takes 
place in them near Loonar. The beds on the edge of the singular crater!form hollow are 
the usual basalts and ainygdaloids abounding in kernels of agate, carbonate of lime, zeolites, 
&c., coated with green earth as usual. No 'dykes whatever were observed. Ash certainly is 
met with, but it is the ordinary vesicular ash of the traps, full of zeolite, and such as may ho 
found everywhere in the Deccan. The hollow is as nearly as possible circular, rather more than 
a mile in diameter. The sides nearly precipitous. A stream from a small spring which supplies 
Loonar with water has cut a shallow ravine down to the lake which occupies the depression. 
There is no outlet. The sides of the crater to the north and north-east are absolutely level 
with the surrounding country, while to the west, south-west, south and south-east, there is a 
raised rim never exceeding 100 feet in height, and frequently only 40 or 50 feet. In this low 
raised rim there is no trace of distinct ash-beds or lava Hows; it is unquestionably composed 
pf huge blocks of trap, precisely similar to those of the beds below irregularly piled together. 
The types of the ordinary Deccan traps are so peculiar that their identification is easy. 
The mass of materials forming the rim resembles those thrown out of an artificial hole in 
everything except the size of some of the fragments. 
The trap beds dip away from the edge of the hollow generally, but irregularly, and 
appear to owe their dip entirely to disturbance. 
There is thus a total absence of everything which in general characterizes a volcano. 
And yet without volcanic action it is inconceivable that such a hollow should have been 
formed. No process of aqueous denudation can explain it. The rim, too, appears formed 
from the fragments ejected from the crater. True, this rim cannot contain one thousandth 
part of the material removed, hut the majority was probably reduced to fine powder by 
repeated ejections, scattered over the country, and removed by subsequent denudation. 
t In Sheet So of the Indian Atlas, so far as it was traversed, the mapping appeared good, hut the shading of the 
hills is greatly exaggerated, No one would imagine by looking at it that the great scarp represented as stretching 
away to the south of east from Loonar is only in reality about 100 feet high in general, and never, so far as I saw, 
much over 150 feet, if it is anywhere so much. Moreover, it rises gently and not abruptly. The country in general 
is comparatively level, low flat topped vises, and broad undulating plains, less cultivated than is the case to the 
westward. No hills of any height occur. 
