Miocene foraminiferal paleoecology of the basin of Vence, Southeast France

Abstract

Two transgressive—regressive cycles occurred in the Basin of Vence during the Miocene. The sea transgressed the region from the southeast direction. The first cycle commenced in the Early Aquitanian and probably ended in the Burdigalian. A second minor cycle was terminated by Late- to post-Miocene tectonic activity related to the last phases of the Alpine Orogeny in the region. Benthonic and planktonic foraminiferal assemblages indicate that the Miocene deposits represent littoral to mesopelagic zones in the tropical to temperate Miocene sea in which turbidity currents were active. These assemblages, comprising characteristic shallow-water forms ( Cibicides lobatulus, Uvigerina peregrina, U. subperegrina, Nodosaria ovicula, Guttulina communis, Siphonodosaria nuttalli and Spiroplectammina carinata) and deep-water species like Hoeglundina elegans, Lagena striata, Marginulina glabra, Bulimina elongata, Melonis pompilioides, Sphaeroidina bulloides and Pullenia bulloides plus abundant planktonic foraminifera, in the western and eastern parts respectively, indicate that the sea shoaled progressively westwards. Lithology, macrofaunal content and sedimentary and biogenic structures support these conclusions. Renewed post-Miocene transgressions in the area extended only as far northwest as the Pliocene basin of the Var.