70 GEOLOGICAL RESEARCHES IN 



CHAPTER VIII.' 



GEOLOGICAL SKETCH OF THE ROUTE FROM THE GREAT 

 WALL TO THE SIBERIAN FRONTIER. 



The route, here described, after following for about 100 miles that along which 

 the measurements of MM. Fuss and v. Bunge were made, leaves this and remains 

 about 60 miles to the west of it for most of the distance, joining it again in about 

 latitude 47° N. 



The journey was made in the months of November and December, the ther* 

 mometer ranging from +15° to — 28° F., with an almost incessant, strong, north- 

 west wind. This, and the fact that we travelled seventeen hours a day, will, I 

 think, be a sufficient excuse for the meagreness of the information. Nothing but 

 the absence of all geological observations over this immense region, prompts the 

 insertion of the following scanty notes. 



Nov. 21, 1864. Leavmg Kalgan we ascended to the plateau by the Tutinza road.^ 

 For the first two or three days the intensely cold winds made it impossible to take 

 notes. The great volcanic formation, which we have seen forming the southern 

 edge of the table-land for a long distance to the westward, extends from thirty to 

 fifty miles in this direction, as the only rock in place, and the conformation of the 

 surface is similar to that with which we have become acquainted in describing the 

 journey to the west, only the valleys are generally broader and more shallow. 



During the next fifty miles our route crossed several low ridges, chiefly granitic, 

 the intervening plains being covered with the detritus of quartz and metamorphic 

 sandstone. This is succeeded by a rolling country with hills of red granite, diorite, 

 and greenstone porphyry, which continues to beyond the low granite ridge of Mt. 

 Ugundui.^ The fragments on the surface of the plains were mostly of granite and 

 quartzitic sandstone, together with scattered pieces of lava and pebbles of chal- 

 cedony, agate, etc. 



Nov. 26. After passing Mt. Ugundui the character of the country underwent a 

 marked change. Our road lay, from the last-named mountain to the Mingan hills, 

 through a depression. In the distance the flat outline of the plateau was seen on 

 all sides, the intervening country being cut up into isolated knobs and ridges by 

 numerous water-courses and lake beds. The structure of the knobs shows them to 



* See Section on PI. 1. 



" This portion of the road, as far as the summit of the plateau, was described in a previous chapter. 

 » Many of the names of places, etc , used in this sketch are given on Klaproth's large map of Cen- 

 tral Asia. 



