Sedimentary environment and synecology of macrobenthic assemblages of the marly sands and red-algal limestones in the Korytnica Basin (Middle Miocene; Holy Cross Mountains, Central Poland)

Abstract

The facies development of the upper part of the Middle Miocene (Badenian) sedimentary sequence of the Korytnica Basin (Holy Cross Mountains, Central Poland) was controlled by high hydrodynanic activity (storms) and diversified bathymetric conditions. Deposition of red-algal Iimestones on the rocky submarine ridges and marly sands in the deeper parts of the Basin took place in that shallow, nearshore marine environment. Synecological analysis of the macrobenthic Acanthocardia assemblage of the marly sands shows very high of the lower level infaunal suspension feeders, among which one bivalve species, Acanthocardia paucicostata (Sowerby), represents nearly 34% of the total biovolume. Infauna was dominated by very rapid burrowers adopted to unstabilized environment. The red-algal bank community was composed primarily of epifaunal browsers and suspension feeders.