Presenter: Lien-Kai Lin
Date: 2016/11/03
Abstract
First part, transcurrent tectonics introduction. The strike-slip fault system divided into two mechanisms, which are transpression and transtension. Transtension means that extension is a deformation component of bulk strike-slip faulting. Transpression means that shortening is taking place across a dominantly strike-slip fault. On the seismic profiles, there are positive-flower structure in the transpression environment, and the negative-flower structure in the transtension environment. Due to the Riedel shears, the en echelon strat to form, and produce the different structures. During the long time, it will produce the strike-slip duplexes. Fault combine strike and reverse slip is compressional strike-slip duplex, strike and normal slip is extensional strike-slip duplex. Second part, in the strike-slip fault systems, there are four kinds of basins, including fault-bend basin, step-over basin, fault-termination basin, and transpressional basin. Third part, Legg et al,.2015 use the bathymetry data to map the strike-slip fault zones in the California Continental Borderland, realize the structure with seismic data, and then combine the seismicity and focal mechanism to discuss. And, there are many steep faults on the strike-slip fault zones. Finally, I use same methods to study the geologic structure in the offshore area of northern Longitudinal valley. And, this area could be the extension duplex formed by the plate collision.
Reference
Atsushi Noda (2013). Strike-Slip Basin – Its Configuration and Sedimentary Facies, Mechanism of Sedimentary Basin Formation - Multidisciplinary Approach on Active Plate Margins, Dr. Yasuto Itoh (Ed.), InTech, doi: 10.5772/56593.
Legg,M.R., M.D.Kohler,N.Shintaku, and D. S. Weeraratne (2015), High-resolution mapping of two large-scale transpressional fault zones in the California Continental Borderland: Santa Cruz-Catalina Ridge and Ferrelo faults, J. Geophys. Res. Earth Surf., 120, 915–942, doi:10.1002/2014JF003322. (SCI)
Jean Pierre Burg(2016). Strike-slip and oblique-slip tectonics. Available from: http://www.files.ethz.ch/structuralgeology/jpb/files/English/5wrench.pdf