Download or read book Mechanisms of Strain Transfer Along Strike-slip Faults written by Jacob August Selander and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall length of a fault is proportional to the potential size of earthquakes it may produce and its cumulative displacement. Because longer faults are capable of producing larger earthquakes, it is important to understand mechanisms by which faults propagate, how faults may or may not link, and how displacement gradients are accommodated along strike. In order to assess the roles that these mechanisms play in accommodating active deformation, I examine distributed faulting in the Mojave segment of the Eastern California Shear Zone (ECSZ), a broad region of overall dextral shear east of the San Andreas Fault. First, I investigate fault-tip deformation along the northwest Gravel Hills fault. Deformation at this actively propagating fault tip is a combination of en-echelon faulting and folding within a 10-km long damage zone, and broad warping of the surrounding crust over a radius roughly equal to the local seismogenic depth. Elastic half-space modeling of the buried fault tip suggests the presence of a steep displacement gradient over the final 10-15 km of fault length, a portion of which is accommodated via aseismic accumulation of permanent deformation. To address fault connectivity, I focus on a broad restraining step in the Calico- Blackwater fault system and use structural cross-sections to evaluate potential links between these strike-slip faults. I find that hard structural links connect the Calico fault to the Harper Lake, Manix, Tin Can Alley, and Blackwater faults and that approximately 80% of total displacement is transferred from the Calico fault to these intersecting structures. These new structural connections and the suggestion of steep displacement gradients at fault tips predict how late Quaternary slip rates may be distributed along the Calico- Blackwater system and intersecting faults. To test these predictions, I present late Quaternary displacement rates at five new locations on the Calico, Harper Lake, and Gravel Hills faults, and within the hanging wall of the Mud Hills thrust. The distribution of these rates mimics the long-term connectivity patterns shown from my structural interpretations. Slip rates also exhibit a decrease to the northwest along the Harper Lake- Gravel Hills fault, consistent with the expected decline due to fault-tip deformation. Overall, the distribution of geologic dextral slip rates suggests that the Mojave ECSZ is best modeled as a network of short, incompletely connected faults with a significant component of distributed deformation occurring in the crustal volume surrounding major structures.