Active Triclinic Transtension in a Volcanic Arc: A Case of the El Salvador Fault Zone in Central America

The El Salvador Fault Zone (ESFZ) is part of the Central American Volcanic Arc and accommodates oblique separation movement between forearc sliver Chortis block (Caribbean Plate). In this work, a triclinic transtension model was applied to geological (fault-slip inversion, shape volcanic calderas), seismic (focal mechanisms) geodetic (GPS displacements) data evaluate characteristics last stages kinematic evolution arc. constitutes large band transtensional deformation whose direction varies N90° E N110° E. Its dip about 70° S because it comes from reactivation previous extensional stage. A protocol consisting three successive steps followed compare predictions with natural data. results show simple shear plunging 20° 50° W (triclinic flow) vorticity number that mostly higher than 0.81 (simple-shearing-dominated flow). shortening coaxial component would be located according band. It concluded type analytical could very useful in study active arcs, even though only information on small increments available.