PLEISTOCENE DEPOSITS OP LOP-NOR 



369 



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^ ym' 





(13) 1 foot — O ravel. 



miles long by 125 wide. The three middle strands, at heights of 30, 35, 

 and 115 feet, are usually well developed on both sides of the lake (plate 

 31, figure 2, and plate 32, figure 1). The youngest is very faint and 

 recent. As has been said above, the strands agree with the terraces and 

 moraines of other parts of central Asia in size and number, and all three 

 kinds of phenomena appear to be synchronous. The small sixth strand, 

 together with a little sixth terrace and a small modern moraine from 

 which the ice has recently withdrawn, appears to be due to a mild arsial 

 epoch dating from historic times. 



PLEISTOCENE (AND PLIOCENE) DEPOSITS OF LOP-NOR 



At Lop, as at Seyistan, the Pleistocene strophe appears to have been 

 characterized by a series of climatic oscillations, jDart of which preceded 

 those which can be corre- 

 lated with the Glacial 

 period. On both the north 

 and south sides of the salt 

 plain I found clayey de- 

 posits of lacustrine origin 

 alternating with more 

 sandy subaerial beds. He- 

 din describes similar strata 

 at the eastern end of the 

 old lake bed, and I found 

 them far to the southwest 

 near Vash Sheri. They 

 appear to cover an area at 

 least. 300 miles long and 

 100 wide. They have been 

 found to a height of over figure 5. 

 250 feet above the present 

 lake. The accompanying 

 sections (figures 5-10), all 

 of which are drawn on the scale of 40 feet to the inch, illustrate the 

 character of the deposits. Figure 10 shows the most valuable section. 

 It gives the succession of strata as seen along the dry stream bed running 

 south from Altmish B-ulak, a desert salt spring, to the ruins of Lulan, 

 on the north side of the salt plain. It is incomplete at the top and prob- 

 ably at the bottom, and there is a break in the middle. Moreover, it may 

 fail to tell the whole story because the lacustrine strata such as A and B, 

 figure 11, may not reach the surface. Others, such as E, may be very 



(12j 12 /eet — Massive and very saline .sandy letl clay. 



(11) ^0 feet — Red and brown saod. sandy clay, grit and floe evavel. 

 with croes-bedUlDg, leo-ses ei-cetera. 



(101 5 feet — Red sand. 



9) 9 feet — Banded saline red clay 



(71 

 <6i 



(5) 

 (4t 



(3) 

 (2) 

 fU 



6 feet — Massive red clay, very .saline. 



UHCOSFORMITT. 



1 or 2 feel — Reddlnb sandy clay. 



2 feel — Sandy, eallne greenish clay. 



6 feet — Solid greenleb clay. 



9 feet — Gray-green sajidy clay profusely lntet't>edded In the 

 lower pans wKb brownliib red sail. 



'/» fool — Soft yellow sand. 



5 feet — Sandy greenish clay full of reeds and of beds of yel- 



low sand. 



6 feet — Coarse gray sand and etU, witb yellow reed beds ai 



top 



■Section of Lake Bluff 3 Miles East of 

 Chindelik Spring. 



The spring is on shore of old Lop-Nor. 

 inch ^= 40 feet. 



Scale: 1 



