SOUTH-WESTERN PORTION OF KARACHI COLLECTORATE. 185 



developed on the Baluchistan coast farther to the westward, and very 

 probably the marine equivalents of the Manchhar and Siwalik formations. 

 In the Manchhar beds, south-east of this, also, and at a rather higher 

 horizon, a marine bed was found. Light-grey, thick, soft sandstones, 

 obliquely laminated, rest with slight unconformity on a yellow limestone 

 containing fossils in abundance. A.mongst the latter were two species of 

 Pecten (one of them P. subcorneus), Spondylus , Carclita, Cerithmm, a small 

 Clypeaster , and corals. The bed is only a few feet thick, and rests uncon- 

 formably on laminated dun-coloured clays, succeeded in descending order 

 by soft sandstones, silty shales, &c. 



Of course, these beds may all belong to the Makran group, and not 

 Neighbourhood of Ka- to tne Manchhar ; but as the relationship to Gaj 

 r & clli - beds is the same as in the case of the latter group, 



this view is in favour of considering the two identical. The unconformity 

 noticed is probably only local. The beds seen near Karachi are of small 

 interest or importance, and the exposures, as a rule, are poor. There 

 are some masses of conglomerate, apparently of subrecent age, in the 

 plain to the west of the town, and oyster shells are occasionally found 

 associated with them. Manchhar beds appear north-east of Karachi, 

 about 2^ miles from the town, at a place called Guru Goraknath. Just 

 south of the Makran telegraph line, horizontal post-tertiary conglomerates 



are seen resting unconformably on Manchhar beds ; 

 Eelations of Manchhar . 



to Gaj beds north-west the latter dip at a considerable angle and rest upon 



the Gaj group. The Manchhar beds consist of the 



usual grey sandstones and conglomerates with clay nodules. North of 



the telegraph line a conglomerate, apparently identical with that forming 



everywhere, where it is seen, the uppermost bed of the Manchhar group, 



and chiefly composed of oblately spheroidal nummulitic limestone pebbles, 



overlaps the lower beds and rests upon the Gaj group. All the Manchhar 



beds seen at this spot, a considerable thickness, are overlapped in the space 



of less than a quarter of a mile. Here, therefore, the Manchhar beds must 



be unconformable to the Gaj group. A little farther to the north-east, 



the Manchhar sandstones re-appear and are associated with marine beds. 



( 185 ) 



