370 E. HUNTINGTON GLACIAL PERIOD IN NON-GLACIATED REGIONS 



thin where cut by the bed of the stream, although of considerable thick- 

 ness farther toward the center of the basin. In many ways the sections 

 at Lop are much less satisfactory than those at Seyistan. Nevertheless 

 they indicate conclusively that in the main the history of the two regions 

 during recent geological times has been identical. 



P^^fl (8) — fpet— Gravel 



(7) 20 feet — Very solinc rec] clay aad sand 



(6) 2 feet — Yellow and green clay. 



(5) 8 feet — Very nalloe red clny 



UNCONFDnMinf 



(4) .? feet — Red sand. 



(;^) 'i feet — Saltae red clay. 



(2) Vi foot — Banded yreelt clay.' 



(1) 3 feet— Saline red clay. 



— - —Tains. 



(4^ 2 feel— Gi-avel. 



(3) 8 feet — Hard red salt mixed witfi uoine clay. 



(2) 20 feet— Pale red sand and grit 



(1) 8 feet — Yellow clay and sand, saline at lop 



PiGCRE 6. — Section of Bluff at Tulcia 

 Bay. 



South of old Lop-Nor. Scale : 1 inch = 

 40 feet. 



Figure 7. — Section of Bluff 2 Miles West 

 of Koslialangza. 



Near the east end of old Lop-Nor, on tlip 

 .south .side. Scale : 1 inch ^= 40 feet. 



iOfl arid almost fi-ee from aalL 



i feel— Wliltlsh clny will, o Jltile sand and salt, 

 . ^ — ^ \ N) 1 foot — Saline red clay. 



A careful examination of the Lop sections brings out the resemljlance 

 to Seyistan. First, we have somewhat massive lacustrine deposits of 

 pure, light-colored clay, varying in tint from almost white to pale grefen, 

 or, on the edges, pinkish yellow; second, there are numerous sandy yellow 

 reed beds, indicative of swamps, sucli as now occur in central Asia on the 



shores of lakes or in tlie 

 flood-plains of rivers ; 

 and, third, we have .de- 

 posits of gravel or red 

 clay, pointing appar- 

 ently to arid epochs of 

 lake contraction. Eeed 

 beds appear to play a 

 much more important 

 part at Lop than at 

 Seyistan. This is large- 

 ly because at Lop most 

 of tlie sections are from 

 near the borders of the 

 old lakes, whereas at Seyistan they are from more central parts. Another 

 difference is the much greater amount of salt at Lop, both in the lacus- 

 trine and subaerial deposits. This corresponds with present conditions. 

 The vicinity of Lop-Nor is one of the most saline places in the world. 

 The river Tarim, though drinkable, is so full of salt that it can not be 



~ V '^' ' 'fel— Wlilllah clay wlih a IlLUe sand and salt, 



121 S feel- Yellowish sand, with many reads and An. 

 eolljin cioss-lieddlnu 



<11 IS feet— Vi,|y hard, .saline 



Figure 8. — Section of a Z-story "Yardang," or Molian 

 Mesa. 



The mesa is about 25 miles east by south of Altmish 

 Bulak, north of old liOp-Nor. Scale : 1 inch = 40 feet. 



