42 
Records of the Geological Survey of India. 
[vol. v. 
that the whole Biluchistan and Persian Coast from near Cape Monze to Bushehr, a dis¬ 
tance of over 1,100 miles, and the islands lying off it, consists of the same group of rocks. 
This group, which is of tertiary age and newer than the nummulitic series, may con¬ 
veniently he named .the Makran group. 
The salt formation in Hormuz and other places in the neighbourhood is far more 
ancient. Singularly enough, no nummulitic rocks are known to come down to the coast 
throughout the area described, although Cape Monze near Karachi consists entirely of them, 
and I learn from Major St. John that they form the second range of hills inland of Bushehr, 
between that port and Shiraz, and thence extend far to the southward, perhaps nearly or 
quite reaching the shores of the gulf near Eas Mutaf. The only other formation observed 
on the coast is the sub-recent shelly limestone or calcareous grit, identical with that 
found on the western coasts of India and known at Bombay as “littoral concrete” or 
“ shell concrete.” There are thus, in descending order, so far as I have seen, three distinct 
systems of rocks exposed on the Makran and Persian coasts; these are, in descending order: 
1, littoral concrete (sub-recent); 2, Makran group (post-nummulitic); 3, Hormuz salt for¬ 
mation (of unknown age). I shall describe each briefly, premising that the Makran group 
is the prevailing formation throughout the coast, the other groups being merely local. 
Hormuz salt formation .—The island of Hormuz, once the centre of the trade between 
India and Europe, is one of the most singular places on the surface of the earth. Except 
at a few spots on the sea shore, it is destitute of vegetation, and consists of a mass of 
craggy hills of singularly confused forms, but of small elevation, with very few peaks rising 
above the general level, and of brilliant colours, scarlet and purple predominating. One 
peak, a little above the rest, is of pure white, as if covered by snow, and some valleys on the 
westward side of the island are equally filled with a white mass, suggestive of glaciers. 
Other peaks aro black. 
In the portion of the island south of the old Portuguese Port, which I examined, the 
mass of the hills consist of rock salt, more or less pure, frequently mixed with a reddish 
earth. Beds of volcanic origin, dolerites and trachytes, some of them much decomposed, are 
associated with the salt, and some shales and sandy beds aro also interstratified. All 
apparently belong to the same series, but the rocks aro much disturbed, beds of salt and 
volcanic bands alike dipping at high angles. At the spot examined by me the average dip 
is about 50° to the north-east. On the opposite side of the island, the strike appeared to 
be nearly the same, but the dip is reversed. 
Micaceous iron in abundance is associated with the salt, and I found crystalline masses 
of anhydrite, and peculiar isolated crystals of carbonate of lime. I had not time to visit 
the white peak, but I have been assured that it consists of salt. 
In the Island of Hanjam, salt-rocks crop out, every here and there, from beneath the 
Makran group. They may always be recognised by the surface having fallen in through 
the washing away of tho salt, and the consequent formation of peculiar largo crateriform 
hollows. Upon the beds of the salt series the tertiary rocks of the Makrdn group, or at 
least beds which I believe to belong to that group, are seen resting quite unconformably. 
The same unconformity is seen in the large island of Kishin or Jezirak at Tawilah, in 
which are several outcrops of the salt series, easily recognised, even at a distance, by their 
red colour and irregular craggy surface, the latter due to their being so largely composed of 
soluble rock salt. Towards the northern end of the island, at a spot which I visited, there 
are some largo salt caves dug in a bed of very pure rock salt, from which considerable 
quantities of the mineral arc removed for export. 
