IS 
Records of the Geological Survey of India. 
[VOL. X. 
from three to four feet in diameter, whilst remains of much larger blocks, which had fallen to 
pieces, but which could not have measured less originally than twelve to fifteen feet in 
diameter, were seen about Lowo. These boulders appear to have been brought from a distance, 
and there is some reason for supposing that they may have been transported by ice, as the 
underlying surface of the Malani porphyries near Pokran was in one instance found to be 
grooved and striated. 
These beds also can be identified with no known Indian formation. The shales were 
found around Lowo and Pokran, and some quartzites, limestones, &c., of ancient appearance, 
but which are very ill seen in places west of Pokran, may belong to the same series. Some 
shales which were observed in a tank at Dechu, 60 miles west-north-west of Jodhpur, and 
about 30 east-south-east, of Pokran, may be the same. Some softer shales which occur at 
Jodhpur should more probably be referred to the next group. 
3. Jodhpur sandstones ■■—The sandstones which cover a considerable tract of country 
in the neighbourhood of Jodhpur are usually coarse in texture and almost always dull red 
in colour, though occasionally white or brown. As a rule, they are purely quartzose, but 
they sometimes contain felspar, and in places they are highly micaceous, the mica being 
arranged in layers, so as to produce a shaley structure. Small pebbles occasionally occur 
and arc chiefly composed of quartz, but the rock is not usually conglomeratic ; it is, however, 
often obliquely laminated, and the surfaces of slabs are frequently ripple-marked. The beds 
are quite unaltered and often nearly horizontal, rolling about at low angles. 
Except for their being rather softer, there is little, if anything, to distinguish these 
sandstones from some of those belonging to the Yindhyau series. No rocks of this series 
have hitherto been detected west of the Arvali bills, the great Yindbyan area commencing 
several miles to the eastward of that range. The reference of the Jodhpur sandstones to 
the Yindhyans is little more than a suggestion ; they resemble the beds of that series more 
than any other known Indian formation, but it is quite possible that, they may belong to a 
different horizon. 
The Jodhpur sandstones were not noticed south-west of Jodhpur. They are found for 
some distance west of the town and for many miles to the northward, their extent in this 
direction being quite unknown. They are found stretching from Jodhpur to Pokran, a 
distance of 90 miles, but much of the intervening country is so completely concealed by sand, 
that it is impossible to say whether any breaks occur. 
4. Balmir sandstones .—The next three groups belong in all probability to the Jurassic 
series ; marine Jurassic fossils being found abundantly in the two upper. At Balmir and 
in some bills to the eastward a considerable thickness of sandstones, grits and conglomerates 
is exposed, the characteristic beds being whitish or grej- sandstone, very fine and compact, so 
compact indeed as to break with a sharp concboidal fractnre, and to have a sub-vitreous lustre 
on the fractured surface. With these beds coarser and finer sandstones are associated, the 
finer passing into a compact hard shale, whitish in colour, but sometimes veined and 
blotched with purple, and at times entirely purple. There are also bands of coarse con¬ 
glomerate towards the base, containing, atPilmir, pebbles of the underlying Malani beds. 
A few fragmentary remains of plants were found in these beds, but none sufficiently well 
preserved to be determined with certainty. 
Similar rocks, rather less hard, occur near Naosir, Sanplia and Sarun, 30 miles east of 
Balmir, the intervening ground being concealed by sand-hills. 
East and south-east of Jesalmfr, beneath the marine Jurassic beds of the next group, a 
considerable thickness is exposed of grey, white, and brown sandstones, interstratified with 
numerous bands of hard black and brown ferruginous sandstone and grit. The base of these 
