The conceptual sedimentary model of the Lower Danube loess basin: Sedimentogenetic implications

摘要

New information on the entire Lower Danube Basin was obtained through the selection, reworking and integration of previously published data concerning the loess accumulations from the Romanian Danube Plain, Bulgarian Danube Plain, and Dobrogea Highland. A conceptual sedimentary model was outlined, based on the integrated textural and isopach maps of the Lower Danube loess and loess-like deposits. The loess in the Lower Danube Basin appears as an accumulation with the coarsest-grained and thickest loess deposits situated along the Lower Danube River channel. Both grain-size and thickness gradually decrease to the basin margin. During the initial genetic stage, the Lower Danube loess basin functioned as a large flood plain. The alluvial and eolian loess generation stages repeatedly alternated. Several sources supplied the Lower Danube loess clastics, determining the Danubian, Carpathian/Balkan and Black Sea littoral provenance of the detrital material.