Abstract

ARNAIZ-RODRIGUEZ, Mariano S.; SCHMITZ, Michael  and  AUDEMARD, Franck. Crustal structure of the Lesser Antilles arc estimated from receiver functions. Rev. mex. cienc. geol [online]. 2016, vol.33, n.3, pp.286-296. ISSN 2007-2902.

By applying receiver functions technique we studied the crustal thickness and mechanical properties of the Lesser Antilles Arc. We gathered teleseismic data recorded from broadband stations deployed along the arc by different networks. The analysis of P-to-S conversion and crustal reverberations allowed us to estimate the Moho depth and the average crustal Vp/Vs ratio under nine stations. The results were corroborated with forward gravimetric modeling of the long wavelength component of the Complete Bouguer Anomaly along the structure. The Moho depth ranges between 22 and 32.4 km. The distribution of thick and thin crust is closely related to variations of the convergence rate of the subducted lithosphere at the Tiburón fault system. Poisson's ratio ranges between 0.266 (Vp/Vs = 1.777) and 0.3 (Vp/Vs = 1.870). Higher values are consistent with a Mesozoic basement, related to the Greater Antilles Arc, found in the northern section of the Lesser Antilles Arc.

Keywords : Lesser Antilles; receiver functions; crustal thickness; Poisson's ratio.