Structural and Stratigraphic Analysis of the Dinaride Thrust Belt: A Frontier Exploration Province in Central-Southern Europe

Abstract

The Dinarides are a 200-300-km-wide southwest vergent fold and thrust belt extending along the eastern margin of the Adriatic Sea. The complex and varied structural and stratigraphic relationships can be used to define three major tectonic units: the internal, central, and external Dinarides. In the Internal Dinarides, platform sequences deposited in the Early and Middle Triassic underwent rapid subsidence and drowning in the Late Triassic and Early Jurassic along with rifting and subsequent formation of oceanic crust. Melange and flysch were deposited during the late Jurassic through Cretaceous as the developing thrust belt encroached upon the northeastern margin of the Dinaride carbonate platform. The Dinaride carbonate platform forms the cores of the central and external Dinarides and is composed primarily of Permian-Triassic clastics and evaporites overlain by Middle Triassic through early Eocene platform carbonates. The entire sequence is overlain by late Eocene and early Oligocene synorogenic flysch. In the central Dinarides, late Jurassic and Early Cretaceous unconformities suggest structural uplift prior to the onset of thrusting. Deformation involves Paleozoic basement and includes a major decollement in the Permian Triassic clastic and evaporite unit. Thrusting in the external Dinarides occurred in the late Eocene-early Oligocene and is restricted to Middle Triassicmore » and younger units with major detachments forming near the base of the Ladinian and within a Late Jurassic-Early Cretaceous evaporite. Important oil source and seal lithofacies occur within intraplatform basins and lagoons in the Mesozoic sequences of the central and external Dinarides. Widespread dolomitized units within the Mesozoic carbonate sequence are potential reservoir zones. The presence of surface hydrocarbon seeps and of existing production on trend to the Dinarides in the thrust belt of Italy and Albania suggest the potential for hydrocarbon discoveries in this underexplored area.« less