590 Notes on Geology and Mineralogy of Affghanistan. 









Although in some valleys it comes to the surface and forms 

 undulating plains scattered with loose fragments, yet in other 

 places it lies deep, and is covered over by several strata of 

 unconsolidated sands and clays ; such, for instance, is the 

 case between Kishk-i-nakhood and Kak-i-chowpan, and the 

 Karaez, or line of wells, by which at the latter place the 

 patch of cultivation is watered, is sunk through those sands 

 to some depth without exposing the conglomerate. The 

 surface here slopes down as usual from the distant hills to- 

 wards the river Argandab, which pursues a westerly course 

 across the valley, and skirts the edge of the red southern 

 desert. The ground is scattered over with fragments of 

 volcanic rocks, granites, quartz and limestones, and beneath 

 these is first a stratum of loose greyish sand of considerable 

 depth overlying a second stratum of a yellowish-coloured 

 sand, and beneath this again is a stiff marly clay ; the water 

 appears to be held in the clay, and is brought by a succes- 

 sion of wells connected by a subterranean channel, from the 

 foot of the hills down to the cultivable lands extending along 

 the right bank of the Argandab, at a height which is inac- 

 cessible to the water of the river, and which, but for this 

 artificial irrigation, would necessarily remain for ever waste 

 land. The conglomerate, although not perceptible at Kak-i- 

 chowpan, comes to the surface shortly after leaving it, and 

 with the occasional occurrence of a patch of alluvial soil, 

 continues to form a broken and undulating plain up to the 

 banks of the Helmund, from whence it stretches away again 

 beyond Greeshk for many miles, both to the west and south, 

 for it is met with as forming the solid substratum thirty 

 miles below the fort at the junction of the Helmund and 

 Argandab, where stand the ruins of the ancient town and 

 fortress of Killa Beest. 



Captain E. Conolly, in speaking of the Helmund, remarks 

 that — " As soon as it has left the hills, its bed is generally 

 four or five miles in breadth, the water more easily pene- 



