Microzonation of the Linares, Northeast Mexico area, based on geology and shear-wave velocity measurements

Abstract

We determined the velocity structure of S-wave (V_S), P-wave (V_P) and the average shear velocity to 30 meters depth (V_s30) at 30 locations in the Linares, Nuevo León area. V _s and V _P measurements were made from seismic refraction profiles. Four different lithologic units were defined in the upper 30 m: silts with 338 m/s and 221 m/s for V _P and V _s respectively, which correspond to the lowest velocities measured in the area; Quaternary deposits with 957 m/s and 559 m/s for VP and VS; Tertiary conglomerates with 2471 m/s and 1220 m/s for V _P and V_s; and shales of the Upper Cretaceous Mendez Formation with 3195 m/s and 2149 m/s for V _P and V_s. Sites of class C (V_s30 < 760 m/s) are dominant in the area, corresponding to maximum thicknesses of less than 16 m of soft sediments.