.168 
Records of the Geological Survey of India. 
[voi.. XI, 
Not a single bed below the Khirthar limestone (No. Ij can be recognized as 
identical with any of the formations in the Laki range, although the distance 
between the two localities is only about 90 miles. In the upjier Gaj section, 
there are no fossiliferous brown limestones, no trap, no olive shales with Gardita 
heaumonti, no dark ferruginous sandstones nor hippuritic limestone. The sand¬ 
stones Nos. 6 and 7 may represent the lower Raiukot beds, but the resemblance 
is not great, and there is no palaeontological connexion between the two. 
The examination of the section was hurried, and it is far from improbable 
that some fossiliferous bands may have been overlooked, but no distinct break in 
the sequence was detected; perhaps for want of palmontological evidence. The 
division between upper and lower Khirthar, and between the latter and the 
supposed cretaceous beds, is arbitrary; the limestones No. 8 contain the same 
species of NwmmuUtes as Nos. 2, 3, and 4, and no fossils were found below No. 9. 
The sole reason for distinguishing the 6,000 feet of beds, fi-om No. 5 to No. 10 
inclusive, as lower Khirthars, is that, as the nummulitic limestone No. 1 is 
the same bed at the Gaj as in the Laki range, some of these lower beds must 
represent the Ranikot group. At first it was supposed that all the lower beds 
on the upper Gaj section were tertiary, and the lower Khirthar beds were esti¬ 
mated to have a thickness of 10,000 feet, but on subsequently reading more 
carefully Dr. Cook’s account of the geology of Kelat,i and Dr. Carter’s notes 
on Dr. Cook’s discoveries,^ it appeared to me that the peculiar fine-grained 
banded limestones No. 11 must be the same as some red and -white limestones 
extensively developed at no great distance to the north-west. These red and 
white limestones pass down into some argillaceous beds (perhaps the same as 
No. 12 of the above section), in which Dr. Cook found Ammonites, and he con¬ 
sequently classed both rocks as mesozoic. 
It is probable that the beds below the Khirthar limestone occupy a large 
tract in Baluchistan to the west of the Khirthar range, for similar beds are seen 
to the westward from the crest of the hills as far north as Darhy4ro. Again, 
west of the Habb river, forming the western boundary of lower Sind, the whole 
Khirthar formation appears composed of shales, maids, and sandstones, closely 
resembling the lower Khirthar beds of the upper Gaj section, and an enormous 
mass of similar beds is found to the westward in Makran.* A peculiar banded 
red and white limestone, so closely resembling that on the upper Gaj that these 
two are probably identical, forms a small hill at Gadani on the sea-coast, about 
25 miles north-west of Karachi. 
Khirthar group .—The nummulitic limestone of the Khirthar and other 
ranges in Sind varies much in thickness, and the original estimate of 3,000 feet 
may have been excessive, though it is doubtful whether it is too high in the 
northern part of the Khirthar range, where the limestone must be very thick. 
At the Gaj, as we have seen, this bed does not exceed 1,000 or 1,200 feet in thick- 
• Bom. Med. & Phys. Soo. Trans. Norember 1860. I am indebted to Br. Cook for a copy 
of this interesting paper. 
2 Jour. Bom. Br. Boy. As. Soc., VI, p. 184. 
^ Eastern Persia, II, pp. 460, 473, 
