Major Events and Stages in the Sedimentary Evolution of the Paleogene Promina Basin (dinarides, Croatia)

Babi}, Lj. & Zupani~, J.: Major events and stages in the sedimentary evolution of the Paleogene Promina basin (Dinarides, Croatia). Nat. Croat. Vol. 16, No. 4, 215-232, 2007, Zagreb. A study of sedimentary successions in different parts of the Eocene-Oligocene Promina basin has revealed major changes in the evolution of upper Promina Beds (PB). The first one refers to the origin of the erosional surface cutting different units ranging from Cretaceous limestones to different parts of older PB. It was formed during the fall of relative sea-level, and corresponds to a sequence boundary. This surface is overlain by onlapping alluvial sediments during the lowest relative sea level, and its early rise. The next main event is marked by a transgressive surface above the alluvium, that led to the deposition of shallow-marine limestones with diverse biota in the photic zone, as well as their lagoonal equivalents. This change resulted from an increase in accommodation space outpacing the rate of sediment supply. A further change refers to the deposition of mud with planktonic foraminifera on an outer shelf resulting from a further rise in the relative sea-level, which halted deposition of shallow-water limestones. The subsequent progradation of shelf and delta was related to the slowing down of the creation of accommodation space compared to the increase of sediment supply.