Deformation Characteristics Of Huangbeiling Nappe Tectonic And Its Metallogenic Relationship In Luanchuan Ore Concentration Area

The collision of the Yangtze Plate and the North China Craton started at theNeoproterozoic and the basic near EW-NW tectonic lines in east Qinling orogen areformed in the following intra-continental orogeny. Luanchuan ore concentration areais located in the middle part of the thrust nappe structure named Funiu Mountains inwhich is Huangbeiling thrust sheet that has be made up by lots of thrust nappes withtheir direction from north to south. It is more beneficial for researching of thrustnappe and the relation between thrust nappe structure and mineralization. This thesisget a series of cognition and achievement by analyzing a lot of information andcarrying out experiments of microstructure, EBSD and sandbox model, followingresearch developed from macro to micro and macro.1.Belong to the thrust nappe structure named Funiu Mountains, Huangbeilingthrust sheet is made up by Luanchuan group, whose southern boundary is theLuonan-Luanchuan Fault and northern boundary is Zhuyuangou Fault. Thecharacteristics of Huangbeiling nappe structure are the duplexes. In this area, thephenomenon of structure is abundant. They can reflect the direction of nappe structurewhich is form south to north on the large scale. Another aspect，by experience ofmicrostructure, we can recognize the brittle deformation, the ductile deformation andthe shear orientation which are mainly left-lateral, that also prove the righting ofprevious work.2. By EBSD technique of precisely and rapidly determining the crystall ographicorientations and describing grain boundaries of crystal grains, we confirms, in thisarea, quartz in the quartzs sandstone of Nannihu group are the high temperature fabricunder the high temperature effect, reflecting the shearing of early phase’s NNE-SSWand the latter’ NWW-SEE. Meanwhile, the calcites in marble of Meiyaogou group arelow temperature fabric under the low temperature effect, reflecting the near S-N’sshearing. 3. Construction of sandbox model experiment of the study area revealsmorphological characteristics of nappe structure and the value of slip layer ofBaishugou group. In the meantime, experiment show the numbers of nappe structure’sfaults, faults surface’s expansion rate (The fault rate for deep development extension)and slip rate (fault plane by nappe side move forward rate)have differentcharacteristics at different stages of evolution. Preliminary concluding that fault’sformation, fault’s expansion as one stage and fault’s moving is another stage.4. Through comprehensive study, this thesis discusses the Luanchuan oreconcentration area of thrust nappe tectonic evolution process, analyzes the Luanchuanore concentration area of thrust nappe structure’s characteristics at different stages.Besides, the preliminary Huangbeiling thrust nappe of Luanchuan ore concentrationarea evolution model has been established.5. Appearance of the thrust sheet was earlier than deposits, in Luanchuan oreconcentration area, by characteristics’ means of thrust nappe tectonic rock-controlling, ore-controlling. Fracture system formed at thrust nappe tectonic evolutionstage and the crust melt which cause the nappe extrusion, thickening and the additionof the upper mantle, these are beneficial for deposit forming. For Yanshanian periodto the late Yanshanian stage, the ore-forming materials upwelled and ore depositformed by tensile fracture of stretching.