Evolution of the stress field near the Arava basin located along the Dead Sea Fault system as revealed by joint sets

Abstract

To reveal the development of the stress field near the Arava basin located along the Dead Sea Fault system, we characterized joint sets that were exposed mainly in the Santonian and Eocene chalk rock outcropping in the study area.In total, ~2600 strike orientations of single-layer joints (SLJ) and multilayer joints (MLJ) mirrored four main stress fields: 1) σHNW(J1-326°), 2) σHNNW(J2-343°), 3) σHNNE(J3-033°), and 4) σHN (J4-360°).The results showed that the relatively lower values of the fracture spacing ratio (FSR) and their standard deviations in J1 implied that J1 was formed during the burial stage of the Eocene chalk formations. The inconsistency between the statistical parameters of the log-normal distributions of joint spacing and FSR raised doubt about the applicability of the “saturation joint density model” in our studied area.The joint sets characteristics suggest that the regional σHNW operated during the Eocene. During the Miocene, the regional stress field changed clockwise to σHNNW, probably in association with the early stage of transform motion along the Dead Sea Fault. In the Pliocene-Pleistocene, the σHNNE and σHN local stress fields both operated and were accompanied by a tensional stress field that can be identified in the intensive normal faulting evolved along the western Arava basin margins.