La Fm Puerto de La Losa (N de Granada, E de Jaén): una nueva unidad estratigráfica, paleogeográficamente significativa, del Paleógeno Inferior Prebético

Abstract

A new unit has been recognized in the Prebetic of the northern part of the Granada Province and eastern part of the Jaén Province, herein defined as La Losa Pass Fm and dated with planktonic and larger foraminifera as late Thanetian-earliest Ypresian. The La Losa Pass Fm, which is mostly made up of carbonates, is comparatively thin (up to 16m), but areally extensive, and it exhibits small and very gradual lateral facies changes. In contrast, the overlying Cañada Hermosa and Nablanca Fms (Ypresian-Lutetian) show important thickness variations (40-300 m) and rapid lateral facies changes. Such differences are attributed to a change in synsedimentary tectonism, from a period of quiescence recorded by the slow, near uniform subsidence of the La Losa Pass Fm to another of more active tectonism responsible for the differential subsidence and facies changes ofthe Cañada Hermosa and Nablanca Fms