OUTLINES OF GEOLOGY OF YUNNAN. 57 



Ta-li Fu and Yunnan Fu or between the former place and Yung- 

 ch'ang Fu. 



(b) Eastern Yunnan.— The deposition of the Red Beds com- 

 menced here with thick conglomerates and ended with red shales 

 and sandstones containing beds of salt and gypsum. The close of 

 the Permian was marked by wide-spread volcanic eruptions, the 

 andesites and basalts of which attain an extraordinary thickness 

 to the north of Ta-li Fu in the Yang-tze valley and further east 

 also. The effect they have on the scenery cannot be described better 

 than in Deprat's words : — 



' Entre la region des lacs et le haut Fleuve Bleue (Yang-tze) les 

 eruptions basiques se multiplient et les enormes coulees de diabases, 

 labradorites et basaltes superposees, pincees dans des plis de vaste 

 amplitude provoquent Tapparition dans la topographic d" enormes 

 croupes arrondies, s'elevant a une altitude tres considerable et con- 

 trastant vivement avec les formes juxtaposees des calcaires carboni- 

 feriens. Les regions occupees par ces roches sont ordinairement tres 

 steriles, et le caractere denude de ces longues cimes arrondies est 

 vraiment caracteristique." (De., p. 5). 



(9) The Triassic System. 



(a) Western Yunnan. — A belt of Triassic rocks about 12 miles 

 wide occurs near Yunnan Hsien to the east of Ta-li Fu and appears 

 to strike north into the Yangtze valley where it is at least 30 miles 

 wide. Its further extension to the north beyond this region is nor 

 known, and it appears to come to an end a short distance to the 

 south of the Yunnan Hsien area as the map shows. A large collec- 

 tion of fossil remains has been made from the rocks of this basin, 

 the commoner types of which are marls, sandy shales, soft sand- 

 stones and occasional limestone horizons. The fauna is sure to prove 

 a most interesting one, but as the collection has not been examined, 

 it is impossible for me to fix the horizons of the various beds them- 

 selves. If a guess may be hazarded, the general appearance of the 

 fossils seems to indicate that both middle and upper Trias aud 

 perhaps Rhaetic beds occur. The Triassic coals of the basin are of 

 considerable economic importance. 



Another Triassic basin was found between Meng Chu and Ssfi- 

 mao in South-western Yunnan but as only one rapid traverse was 

 made across it, its limits are not known. Middle Trias horizons 

 seem to be represented in it. 



E 



