GEOLOGICAL FORMATIONS. 6S 



interstratified, but they usually form but a small portion of the mass, 

 although their greater hardness renders them conspicuous. This marl 

 formation extends for many hundreds of miles along the coast, and is 

 well seen at Ras Malan, Ormara, Pasni, Gwadar, near Jashk, at the 

 entrance of the Persian Gulf, and on the Persian shores of the gulf itself. 

 The headlands of Ras Malan, Ormara, and Gwadar consist of great hori- 

 zontal plateaus, surrounded by cliffs of whitish marl or clay, and capped 

 by dark-coloured calcareous grit, Ras Malan especially being a table-land 

 rising abruptly to a height of 2,000 feet from the sea. These remarka- 

 ble rocks have been called the Makran group 1 from the name usually 

 applied to the littoral tracts of Baluchistan. 



The Makran group is of marine origin, and abounds in mollusca, 

 echinoderms, &c, most of the species apparently being the same as those 

 found in the neighbouring seas at present. The collections made at 

 Gwadar, Jashk, and other places, have not been sufficiently compared 

 to ascertain whether any are common to the Gaj beds of Sind, but by 

 far the greater portion are distinct; none of the characteristic Gaj 

 fossils, such as Ostrea multicostata, Breynia carinata, Echinolampas jac- 

 quemonti, 8fc, } have been noticed in the Makran group, and the latter 

 appears to be of later age than the miocene Gaj beds. Although there 

 is no resemblance between the typical Manchhar beds and the cha- 

 racteristic rocks of the Makran group, nor, from the widely different con- 

 ditions under which the two formations must have been deposited, would 

 any similarity in mineral character be probable, some of the soft argil- 

 laceous shaly sands in the Manchhar beds near Karachi closely resemble 

 some similar beds in the Makran group near Gwadar. As the coast of 

 Baluchistan has never been examined geologically, all that is known 

 of its structure having been ascertained by brief visits to a few points 

 separated from each other by intervals of from 50 to 100 miles, it is 

 uncertain to what extent the rocks of Sind extend to the westward, and 

 whether any representatives of the Gaj group, especially, exist in that 

 .direction ; but there appears a considerable amount of probability that 



1 Rec. Geol. Surv. India, v, p. 43; Eastern Persia, ii, p. 462. 



( 63 ) 



