The feature of Pingtoushan thrust-nappe structure in Beishan, Gansu

Based on 1:250000 scale regional geological surveys,the paper describes in detail the geometrical,kinematical and dynamical characteristics of Pingtoushan thrust-nappe structure.The thrust is from north to south in direction and the extension pattern of the thrust is pickaback.The thrust-nappe structure of Pingtoushan is formed from end of the Silurian to Early Devonian.It is one of the forms of foreland a rea of arccontinent collision oroginic belt in the Caledonian stage.In Indosinian Stage,the tecnotic movement changed original position of thrust-nappe structure,and formed the present complex tectonic frame-work.