Rare intra-Miocene thrusting event in the southern Carpathian-Balkan belt, Serbia: Permian redbeds above Miocene coal, Resavica nappe

A combined surface and subsurface analysis of the central part of the Carpathian-Balkan fold-and-thrust belt near active coal mines in the Senje-Resavica region (eastern Serbia, southern peri-Pannonian area) reveals a structurally inverted, atypical Neogene configuration. The constraints on the initial thrusting episode show that older Permian hanging wall redbeds are displaced sub-horizontally towards the east/northeast over Mesozoic limestone, with Miocene coals deposited transgressively on top of the latter redbeds. The apparently younger or intra-Miocene compressional stage displaced again Permian redbeds, which were this second time tectonically stacked over coal-rich Neogene sediments. The inverted thrust-related configuration highlights polyphase localized Neogene compression, which contrasts with the widespread Late Oligocene (Miocene) regional extension, subsidence, and partitioning of the underlying Alpine Carpathian-Balkan upper crust. As we will show, the tectonic overthrusting also led to shortening-driven burial of Miocene organic material, thereby influencing the thermal evolution of the crustal footwall and allowing it to reach brown-coal levels. The Resavica nappe, which tectonically transported older Palaeozoic sandstone eastward over Miocene and Mesozoic rocks, is visible both at the surface and underground. By establishing the timing and processes involved in the late-stage sub-horizontal emplacement of pre- and intra-Miocene Resavica nappes (long after the initial Late Cretaceous-Palaeogene nappe stacking), we reveal the crustal mechanism behind rather atypical Neogene compressional events for the first time. The regional-scale data extrapolation shows the presence of pre- and intra-Miocene compressional tectonism affecting Permian redbeds on both occasions. The study concludes with a comparison of this previously undocumented post-late Alpine out-of-sequence thrusting with a few rare examples of regional peri-Pannonian thrusting, particularly within the Transylvanian basin.