湖北铁山褶皱叠加型骨节状石香肠基质层微区有限应变测量与分析

his paper, using the bone-shaped boudins combined with fold as study objects, has studied the characteristics in the matric in microscopic scale. The forming mechanism of the bone-shaped boudinage combined with fold is supported by strain measurement and analysis. Strain measurement and analyses in matrix of the boudinage have been made use of the software straindesk and kinematic vorticity(Wk) contour map, true differential strain（ε1 -ε2）,stratum thickness ratio(S) have been made used of the software surfer. It is shown that in the early stage, bone-shaped boudinage had been formed by the two pure shear; later, overlapped fold on the boundinage because of buckling and differences between mechanical property of rocks. Strain in matrix of the bone-shaped boudins combined with fold is controlled by its competent layer，namely negatively related to the distance away from the competent layer. As a result of competent of the bone joint vein body is stronger rather than boudins, formed the bone neck.