GEOLOGY. 23 



tertiary group. 1 Among the sandy and clayey deposits I was not a little surprised to find 

 true Loess, as typical as it can anywhere he seen in the valleys of the Rhine or of the Danube- 

 I might even speak of "Berg" and "Thai-Loss," but I shall not enter into details on this 

 occasion, for I may have a much better opportunity of studying this remarkable deposit. 

 At present I will only notice that commonly we meet with extensive deposits of Loess only in 

 the valleys. Its thickness varies in places from 10 to 80 and more feet a fine yellowish 

 VMstratified clay, occasionally with calcareous concretions and plant fragments. In Europe 

 the origin of this extensive deposit was, and is up to the present date, a disputed question. 

 Naturally, if a geologist is not so fortunate as to travel beyond the " Rhein- " or " Donau - thai," 

 and is accustomed to be surrounded with the verdant beauty of these valleys, he might 

 propose half a dozen theories ; and, as he advances in his experience, disprove the probability of 

 one after the other, until his troubled mind is wearied of prosecuting the object further. 

 Here in the desert countries, where clouds of fertile dust replace those of beneficial vapour, 

 where the atmosphere is hardly ever clear and free from sand, nay occasionally saturated with 

 it, the explanation that the Loess is a subaerial deposit is almost involuntarily pressed upon 

 one's mind. I do not think that by this I am advancing a new idea ; for, unless I am very 

 much mistaken, it was my friend Baron Richthofen who came to a similar conclusion 

 during his recent sojoiirn in Southern China. 



Yarkand lies about 5 miles from the river, far away from the hills, in the midst of a 

 well cultivated land, intersected by numerous canals of irrigation ; a land full of interest 

 for the agriculturist, but where the geological mind soon involuntarily falls into repose. And 

 what shall I say of our road from Yarkand to Kashghar ? Little of geological interest, I am 

 afraid. 



Leaving Yarkand, we passed for the first few miles through cultivated land, which, how- 

 ever, soon gave way to the usual aspect of the desert, or something very little better. A 

 few miles south-west of Kokrabat a low ridge runs from south-east to north-west. If we 

 are allowed to judge from the numerous boulders of red sandstone and Gryphcea marl, 

 some of considerable size and scarcely river-worn, we might consider the ridge as being 

 composed of cretaceous rocks. But one hardly feels consoled with the idea that in wading 

 through the sand he is only crossing a former cretaceous basin, and that the whole of this 

 country has remained free from the encroachment of any of the csenozoic seas. It is very 

 dangerous to jump to conclusions regarding the nature of ground untouched by the geological 

 hammer. The answer to any doubt must for the present remain a desideratum. 



On the fourth day of our march, approaching Yangihissar, we also crossed a few very 

 low ridges ; but these consisted entirely of gravel and marly clay beds, most of them dipping 

 with a very high angle to south by east, the strike being nearly due east and west. South of 

 Yangihissar the ridge bent towards south-west, and there was also a distant low ridge trace- 

 able in a north-easterly direction, the whole having the appearance of representing the shore 

 of some large inland water-sheet. From Yangihissar to Kashghar we traversed only low land, 

 usually more or less thickly covered with a saline efflorescence, but still to a considerable 

 extent cultivated. 



1 From a note in the diary of May 31st, made on the return journey from Yarkand, it appears that Dr. Stoliczka ultimately 

 considered these rocks the equivalents of some examined north of Kashghar, which he termed Artysh beds. 



