Abstract: The Runiange Formation in the Luhuo-Dawu fracture zone consists of a succession of the highly deformed deep-sea siliceous flysch deposits associated with ophiolitic relict masses and Palaeozoic limestones as allochthonous blocks,characteristic of the sedimentary-tectonic mélanges that have the features of the coexistence of matrix,autochthonous and allochthonous blocks.The Formation may be traced back to the Middle Triassic-the Norian of the Late Triassic.Tectonic-stratigraphically,the Formation is renamed Runiange Group Complex aiming at the correlation with the Jinshajiang and Litang Ophiolite Group Complexes.