20 
[VOL. X. 
Records of the Geological Surrey of India. 
Many of tliese are characteristic Jurassic forms, and are found in the Oolitic rocks of 
Cutch ; the two Cephalopoda, Ammonitesfissus and Nautilus Kumagunensis, being met 
with in the Chari group. 
Above the limestones of Jesalmir, sandstones of various colours, frequently calcareous, 
are seen, hut they are not so well exposed as the beds below the limestones, and it is difficult 
to say whether these upper strata should be assigned to this group or the next. 
No unconformity could be detected between the Jesalmir beds and the underlying sand¬ 
stones which are supposed to represent the Balmir rocks. The lowest beds of the former 
are seen in a scarp a few miles south-east of Jesalmir. At the same time the examination 
made was necessarily cursory, and the existence of a break is rendered probable by the 
occurrence of pebbles, apparently derived from the lower group, in the conglomerates of the 
upper. 
C. Ammonite bed of Kuchri. —At Kuchri, two short marches, or about 25 miles 
west-north-west of Jesalmir, a belt of rocks appears, consisting of dark calcareous sandstones 
resting on soft white sandstone, and capped by a thin bed of buff and brownish limestone, 
weathering red where exposed, and abounding in Ammonites of a yellow colour, belonging to 
three or four species, an Area, oysters and other bivalves. None of the Ammonites appear 
to be Cutch species, though one form is near A. opts, Sow. Above the limestone is 
some grey sandstone with hard ferruginous bands of the usual Jurassic character, and upon 
these beds rests nummulitic limestone. 
The relations of the Ivuchri beds to those of Jesalmir is not quite clear, but apparently 
the former are higher in the series. Still, as no rocks are seen over a considerable propor¬ 
tion of the intervening country, there may be a concealed roll of the strata, or a fault, 
but it is more probable that the beds are nearly horizontal, with a gradual ascending sequence 
to the north-west, and unfaulted, because any kind of disturbance would tend to harden the 
beds and enable them, by resisting denudation, to stand up above the surface. 
7. Nmhnulitic limestone. —This was only seen west of Kuchri. It appears to repre¬ 
sent the lowest beds of the Kliirthar group at Rohri, and it rests directly on the Jurassic 
rocks, no representatives of the lower Eocene (iufra-nummulitic or Eanikot group), Deccan 
traps, or Cretaceous beds of Sind and Cutch being met with.* 
8. Alluvial deposits. —Exclusive of the Indus alluvium, a large portion of the desert 
appears to be covered with deep alluvial deposits. This is especially the case in the Luni 
valley, and the country south-west of Jodhpdr, but large tracts between Godra and Balmir, 
others east ot Balmir, and between Jesalmir* and Pokran, are thickly covered with a sandy 
deposit, which is doubtless at the surface a comparatively recent formation. Many of these 
tracts are covered with blown sand, and the wash from the sand-hills is spread over the surface 
and cannot he distinguished from older sandy deposits. Much of the alluvium, however, 
appears to be of older date than the blown sand, and to have covered the surface before 
the sand-hills were formed. 
9. Blown sand. —An immense area of country is entirely covered with sand-hills, and 
tracts of blown sand are to be found in numerous places from the banks of the 
Indus to the Arvali range. Besides the more isolated hills scattered over the country, 
there ai'e two tracts in especial, in the area traversed between Sind and Jodhpur, in which the 
surface is entirely covered with blown sand. One of these, which is known as the Thar, is 
in eastern Sind, along the edge of the Indus alluvium, and it extends the whole length of 
* I have since seen fragments of the same limestone said to have been brought from south of Jesalmir, the 
locality being probably near Vinjorai. 
