Changing tectonic regimes in the central Costa Rica forearc between the Paleogene and the present: Insights from structural analysis and focal mechanisms

PORRAS, HERNÁN; MESCUA, JOSÉ; DURÁN, PATRICK; CASCANTE, MONSERRAT; GIAMBIAGI, LAURA; MULLER, CYRIL

JOURNAL OF GEODYNAMICS

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2021 vol. 143

0264-3707

We discuss the Cenozoic history of the Central Costa Rica forearc, between 10◦ and 9◦30′ N, based on geological mapping, fault slip data and seismological records.The temporal variability in the regional stress-field suggests a variable and complex deformation pattern. The first stage of deformation, from the Paleogene to early Miocene, was controlled by an extensional regime in the forearc. Afterwards, a change to orthogonal convergence triggered a contractional deformation and subsequent inversion of the sedimentary extensional basins in the middle-upper Miocene. Finally, a transpressive regime has been developed since the Pliocene.