572 Notes on Geology and Mineralogy of Affyhanistan. 



and Gryphaea. The plain is composed of a hard arenaceous 

 clayey soil containing calcareous matter, and at the time 

 when I crossed it in April 1839, was clothed with worm- 

 wood, and decorated with various beautiful flowers, such as 

 the Iris, red and yellow Tulips, pale Hyacinth, &c. It is 

 bounded on one side by mountains of fossilliferous limestone; 

 but towards the South the ranges are not continuous, being 

 formed of detached masses between which the eye wanders 

 down over an arid and desert plain, in all probability blend- 

 ing with the desert sands of Beloochistan. From this plain 

 onwards to Sir-i-ab and Quettah, the formation seems to be 

 the same ; and at the latter place I again procured pebbles 

 of nummulite limestone, and a fragment of a red coloured 

 limestone (probably nummulite also) bearing the impression 

 of an Ammonite, Many of the ravines leading down from 

 the neighbouring heights, are strewed both with nummulite 

 pebbles and fragments of dark-coloured flints, both of which 

 appear to indicate the occurrence of the same rocks as those 

 which were met with at the lower end of the defile and at 

 Sukkur. 



It may now perhaps be useful to revert to the physical 

 appearances presented by the Pass, in order, if possible, to 

 arrive at some just conclusion as to the formations met with, 

 and the causes which have been instrumental to the more 

 recent deposits there observable. When I marched through 

 the defile in 1839, the thick beds of rounded water- worn 

 stones which every where covered the ground, viewed in 

 conjunction with numerous holes in the limestone rocks, 

 which in some parts form the sides of the Pass, led me to 

 think that several deep lakes must at some distant period 

 have occupied the basin-like portions of the defile at Keir- 

 tah, Ab-i-goom, and other places, and that the escape of 

 those waters had strewn the ground with the rounded peb- 

 bles. Subsequent wandering however in other parts of the 

 country, served to convince me of my error in this respect, 





