Keywords: 
• flysch faeim /
• Middle Triadic /
• West Qinling Orogenic belt

Abstract: The main point of views in the paper are 1) the Middle Triassic in the studied area is very thick flysch facies with various characteristics of deep water mass flow sediments dominated by turbidites, 2) the size and thickness of the very thick flysch facies become coarse and thick upward, constituting a whole progressive sequence, 3) besides mass flow sediments, deep water drag flow sediments associated with turbidites were also found, e.g., contourites, and inner wave and inner tide sediments with diversified sedimentary structures, e.g., different types and scales of cross bedings showing water flow waves ripples on sedimentary bed surfaces with different characteristics, 4)if there are coarse sized channel sediments and regularities of vertical sequences and characteristics of ancient flows and rich facies types, the flysch facies are considered to be controlled by deep-sea fan sedimentary facies, 5) compared with the submarine fans developed on the passive and active margins of the plates the submarine fan is considered as an immature one.