Tectonostratigraphic framework of the Dinarides-Hellenides: new insights into hydrocarbon system elements of the Adriatic and Ionian basins

The Dinarides-Hellenides southwest verging fold-and-thrust-belt formed between Greater Adria and the Eurasian tectonic plates. Convergence began in the Late Jurassic and continues today. It involved oceanic subduction of two branches of the Neotethys Ocean as well as continental subduction of Adria beneath Eurasia. Hydrocarbon production and/or field development in Albania, Croatia and Greece prove the existence of multiple productive petroleum systems in the region. However, the differing geological approaches adopted by several countries on the eastern side of the Adriatic Sea have meant that coherent tectonic and stratigraphic models are lacking.

Here, we present findings of a literature review of the geodynamic setting, tectonic evolution and structural styles across the entire length of the external Dinarides and Hellenides and integrate it with stratigraphic and petroleum system development. Emphasis is placed on the regional understanding of hydrocarbon systems and their tectonic and stratigraphic framework. Mesozoic carbonates represent the main reservoir rocks in the region. Syn-orogenic clastic sediments act as regional seals above fractured carbonates. Locally these syn-orogenic clastic rocks also form reservoir units. Organic-rich shales within Triassic evaporite successions and within Jurassic and Cretaceous anoxic basins form the main source rocks. Their facies distribution and provenance are strongly linked to the tectonic evolution of the region as well as changes in source regions in the hinterland.

The examination of published cross-sections showed the differing interpretations on the structural style along strike, the importance of which are discussed. Additionally, our compilation of published chronostratigraphic charts is used to correlate within and across tectonostratigraphic units in order to construct palaeogeographic maps of selected time intervals and evaluate the stratigraphic framework of the region. Preliminary results of ongoing structural and sedimentological targeted fieldwork, investigating the above mentioned topics, are also presented along with some analytical results.

Our syntheses provide new insight into the timing and nature of thrust emplacement, and the distribution of reservoir, source rock and seal units in the region.