582 Notes on Geology and Mineralogy of Affghanistan. 



I 







somewhat resembling a Lithodendron ; the rock is most pro- 

 bably the mountain limestone : but as I had no opportunity 

 of seeing it in situ, I am unable to decide. 



From this range of hills to beyond the river Helmund at 

 Greeshk, the whole country may be strictly termed a vol- 

 canic district, abounding in almost every rock and mineral 

 of the trap formation. In many places are seen trap dykes 

 running up vertically through the limestones, while in other 

 parts vast black basaltic rocks appear to have carried up 

 the secondary strata which now cap them in a nearly hori- 

 zontal position. The surface of the country slopes very 

 perceptibly from the hills on the north of the district, to- 

 wards the great southern desert which bounds Affghanistan 

 on the south, and which is composed of a red-coloured sand, 

 in some places loose and shifting, in others producing the 

 Jowassah or camel thorn, and a few other desert plants. 

 Here and there are seen huge black basaltic rocks jutting 

 up as it were from beneath the sands, which often lie high 

 against the sides of these conical and isolated masses. This 

 desert tract is divided from the cultivable soils nearer the 

 mountains by a well defined line formed by the course of 

 the river Lora, which finds its way down from the Shawl dis- 

 trict through Pisheen, and is eventually lost in the desert 

 sands before it can effect a junction with the more western 

 streams. To the south of the river all is a bare arid waste 

 of loose red sands, with isolated cones of volcanic rocks 

 scattered over it ; while to the right or north, the country 

 gradually slopes up towards the mountains, which descend 

 in nearly parallel ranges from the north-east. Between these 

 ranges are interposed valleys of several miles in breadth, 

 composed of sandy soils intermixed with clays, calcareous 

 earth, and the decomposed particles of trap, which in the 

 vicinity of water yields rich crops of grain and artificial 

 grasses : more usually however these valleys present a broken 

 surface of waste lands, thickly strewed over with rolled 



