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Kedao Group in Yanbian area is a set of terrigenous clastic rockswhich has been recognized asmarine volcanic deposits in Early Permian for a long time. In recent years, the lithostratigraphic meaning of Kedao Group has been recovered, but the tecto-stratigraphic meaning of“mixtite”has been given by some geologists. The authors consider that Kedao Group is a set of continental, terrigenous clastic rockswith alluvial, fluvial and lacustrine deposits on basis of recent studies. The Kedao Group can be compared with Lujiatun Formation in the center part of Jilin according to the same sedimentary rock assemblage, tectonic setting and biological characteristic ( Paraeonodonta-Paraeomutela fauna) , and its geological age belongs to the Early Triassic, which is a p roduct of the pull-apart basin in the orogenic stage after the Late Variscan orogenesis.

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