Paleoseismic evidences in Last Interglacial deposits from Cope Basin (Murcia, SE Spain)

Abstract

Cope basin is a small littoral plio-pleistocene sedimentary basin located in the inner part of the Aguilas Arc tectonic structure (Betic Cordillera, SE Iberian Peninsula). Tectonic activity has driven the recent evolution of the basin promoting a piano like movement of blocks that has conditioned the differential development of morphosedimentary units, however, seismic activity in this basin has not been reported, neither in the historical nor in the geological record. Complex distribution of sedimentary units within the MIS7 – MIS5 sequence is interpreted in this work as the consequence of the joint action of sea-level changes and seismic activity. Evidences of sudden uplift of coastal deposits, as well as the occurrence of liquefaction processes associated to Last Interglacial deposits cannot be interpreted without the action of strong earthquakes in the area. Seismic intensity (ESI-2007) suggest values as high as VIII-IX, what is strikingly higher than expected values in the area