Genesis and composition of the Pleistocene Coralligene de plateau of the Cutro Terrace (Calabria, southern Italy)

Abstract

Abstract: Some mid-Pleistocene carbonate build-ups from the marine terrace of Cutro show theuncommon, biologically-induced change of substrate that is implied in the definition of coralligenede plateau : from coarse, biogenic sediment to the solid framework. The build-ups grew over a basalrhodolithic layer mostly composed of Sporolithon ptychoides which was stabilized and transformedinto a hard substrate by the binding activity and overgrowth of non-geniculate Corallinales (calca-reous red algae). The build-ups are dominated by Titanoderma pustulatum , whose role in biogenicconstruction was previously underestimated, in association with Mesophyllum spp. and locally with Lithophyllum stictaeforme . Intergenicula of Amphiroa cryptarthrodia are common. Key words: coralligenous, bio-construction, hard substrate, rhodoliths, Corallinales, calcareousalgae, Pleistocene. 1. Introduction The term coralligene or coralligenous (acronym = C)is commonly applied to carbonate build-ups currentlydeveloping on Mediterranean hard and soft bottoms,at depths ranging from 20 to 160 m (L