Paleoenvironments and Sedimentation in the Southeastern Margin of Lake Pannon (Western Smederevsko Podunavlje Area, Serbia)

Abstract

The Late Miocene - Pliocene Lake Pannon gradually diminished as sediments sourced from the Alps and Carpathians filled its basin and pushed its northern shoreline southward. Sedimentary successions from the southern margin of the lake SE of Belgrade (Smederevsko Podunavlje area) were studied in several outcrops and interpreted together with literature data referring to the area. Three facies associations were distinguished: offshore lacustrine clays, delta front sands, and delta plain sands with paludal huminitic clays. The facies associations are organized into at least four delta-scale (10-50 m thick) transgressive-regressive cycles. Age of the succession spans from the Sarmatian-Pannonian boundary (11.6 Ma) to the Prosodacnomya dainellii Zone (older than 7.2 Ma), and most of the littoral and sublittoral mollusc biozones of that interval are represented by their characteristic fossils in the succession. These patterns suggest very low subsidence rate, low accommodation rate, and low rate of sedimentation. Although the investigated sections do not display any obvious stratigraphic gap, erosion must have been a major factor determining the apparently low average sedimentation rate. Persistent aggradation of lacustrine-deltaic sediments at the southern margin of the Pannonian Basin aligns with the general aggradational architecture of the basin fill in the high-supply endorheic Lake Pannon.