板内小位移走滑断层构造特征定量表征方法OA

Intraplate small-displacement strike-slip faults cannot be accurately identified and quantitatively analyzed by conventional techniques.To clarify the tectonic characteristics and deformation process of intraplate small-displacement strike-slip faults,structural physical simulation experiments were designed based on the geological conditions of the study area.Taking the Fuman Oilfield in the northern Tarim Basin as an example,laser scanning was adopted to elaborately and quantitatively analyze the deformation features and differences of left-lateral strike-slip fault at each evolutionary stage.This study indicates that the deformation of the FI17 fault zone in the Fuman Oilfield evolves in four stages:diffuse deformation,R-shear fracture,branched fault interconnection,and through-going principal displacement zone(PDZ)connection.During the evolution of the strike-slip fault zone,en echelon anticlines serve as a diagnostic marker for R-shear fracture,and their uplift amplitude represents a vital parameter to classify evolutionary stages.A"Net Deformation Magnitude"method is proposed,which can effectively remove post-tectonic stratigraphic deformations irrelevant to strike-slip-related folds and extract fold geometries and uplift amplitudes solely generated by strike-slip faulting.This method further enables quantitative characterization of along-strike heterogeneities in deformation intensity and connectivity of strike-slip fault zones,thereby realizing integrated seismic-geological interpretation.A case study of the Fuman Oilfield demonstrates that the FI17 fault zone is currently in the branched fault interconnection stage,characterized by alternating through-going and disconnected segments along its strike.The findings establish a geological model for the refined interpretation of intraplate small-displacement strike-slip faults.Furthermore,the newly recognized fault-karst traps associated with R-shear fractures are expected to become promising new targets for hydrocarbon exploration.