Remarks on the Oligo-Miocene extensional episode(s) in InnerDinarides: Towards the tectonic constraints of the origin of intra-montagne basins

Abstract

The ongoing interest in the complex geology of the Dinaric orogen, in particular, its immediate, post-orogenic evolution (post-Lutetian), has produced a number of the tectonic solutions, proposing either extensional stage followed by the subsidence, extensional stage with immense lithospheric thinning resulting in the regional uplift, or even pure uplift episode(s). The unclear Late Oligocene–Miocene tectonic forces are often interpreted as interchange of the crustal-scale driven extensional uplift episodes, presumably affecting the formation of a number of the lacustrine mini-basins, often referred to as the „intra-montagne basins“. A limited number of the available field-based structural interpretations tend to explain the Miocene crustal-rooted extensional episode(s). Despite lacking of the important subsurface data, such as wells-derived thickness and other data, commonly used for the reconstruction of the eventual subsidence stages, the available interpretations provide several deep crustal-scale models of the extensional setting. In order to better understand the timing and mechanism behind the onset of the Oligo-Miocene Dinaride “intra-montagne” extensional episode(s), this study uses the available information of the precursory oblique convergent margins, further proposing the use of a combination of the crustal and the basin modeling tools that could extract more information of the barely available subsurface data (subsidence rate, source-to-sink patterns, etc). The assessment of the recently published surface constraints, allowed the following discussion evaluating a set of the recently proposed crustal-scale “intra-montagne” tectonic models.

Keywords

• late oligocene
• “intra-montagne”
• neogene
• strike-slip
• basin modeling