The post-Neotethyan, oblique subduction-driven narrowing between the tapering northeastern Adria margin and the European promontory (Tisza-, Serbo-Macedonian Unit) culminated during the Late ...Cretaceous. A developing Conacian – Santonian narrowing corridor including the Campanian bimodal magmatism of limited volume is restricted and aligned with the Tisza Unit/East Vardar/Serbo-Macedonian overriding plate(s). These Campanian, sliver-like, mini-magma pools are sealed shortly afterward with the onset and formation of the time-equivalent mélange, along with the Maastrichtian to middle Oligocene turbidites. A typifying segment of this diffuse plate boundary referred to as the Sava Suture Zone, occurs as disconnected outcrop belt, exhumed on Medvednica, Prosara, Kozara, Motajica, Moslovačka Gora, and the Požeška Gora Mountains (Bosnia and Herzegovina, Croatia). The active margin segment, cropping out along the East Vardar Zone/Serbo-Macedonian overriding plate, exclusively boasts several near-surface, rather localized Coniacian-Santonian magma incursions. These Upper Cretaceous limited-sized, magmatic products are hosted in the Ripanj-Pinosava, Rudnik-Topola areas (andesites, lamprophyre) in Serbia and the Klepa Mt. in North Macedonia. Such a disproportional magnitude of near-surface Upper Cretaceous magmatic centers is consistent with the difference between the crustal tectonic components and the discrepancies in mantle-lithospheric processes. However, the locations or plate-tectonic relationships and the reasons why the thrust-stacked magma pools localize and in which area, are not fully understood. The regional geological analysis of the Upper Cretaceous Sava Suture Zone yields a new regional geodynamic interpretation, connecting (i) the Jurassic–earliest Cretaceous closure of Neotethys, (ii) the oblique active margin, pull-apart ‘Gosau-type’ subbasin formation, and the emplacement of restricted volcanic intrusions.
•Late Cretaceous-Paleogene suture zone “Sava Zone” connects Bosnia and Herzegovina, Croatia, Serbia, North Macedonia.•Sava Suture Zone is a composite overprinted oblique plate boundary, characterized by the scarce bimodal magma intrusions.•Santonian mini-magma pools are associated with the Upper Cretaceous reactivation of oblique lithospheric-scale motions.•The corridor contains no solid evidence of any Cretaceous oceanic lithosphere, dismissing the existence of the “Sava Ocean”.
The tectono-paleogeograhic inheritance of barely documented Paleotethyan influence on the Southern Carpathian-Balkan belt is herein reappraised to highlight complex processes occurring along an ...alternative branched configuration of Triassic fossil subduction zone interfaces. The absence of Paleotethyan oceanic accretionary complexes, and the unavailability of rocks returned from poorly traceable Triassic subduction zones allow no conventional insights into its internal structure. In contrast, the adjoining Dinarides and investigated western Southern Carpathian-Balkan belt contain metamorphic rocks ejected from the precursory Late Paleozoic Paleotethyan active margin. An inventory and reappraisal of Variscan and Cimmerian imprints, far-field effects place the peri-Moesian Southern Carpathian-Balkan belt into the overriding plate position above the Triassic Paleotethyan active margin. Ongoing Permian–Early Triassic dragging of underlying Paleotethyan crustal material beneath external segments of the continental margin is contemporaneous with the onset and formation of several episutural back-arc oceans. These include the Maliac Ocean with a here introduced NNW-SSE striking Lower–Middle Triassic marginal shallow-water clastic-carbonate basin of Getic Unit (Gornjak nappe) that is spatially in line with the “Volvi-Therma” western Rhodope aborted Triassic rift system. The carbonate platform deposition was interrupted by a change in the geodynamic regime at the end of the Middle Triassic (inducing mild compressional deformations and the regional uplift resulting in missing of Upper Triassic sediments). The constraints on the investigated sequences yield that the lagged Paleotethyan closure in the Balkan sector occurred during the late Ladinian-Carnian interval.
The Dinarides and Carpathian-Balkans, the western Balkan Peninsula, form an essential link between the Paleotethyan branches of the Adriatic Sea (Montenegro, Croatia) and that related to a ...multistrand Paleo- and Neotethys Vardar oceanic margin (Serbia, North Macedonia, and Greece). These post-Variscan paleo-margins have not been profoundly correlated with the neglected imprints of Paleotethyan closure, early Alpine extension, and subsequent lagged Upper Triassic Cimmerian orogeny until now. The Permian–Triassic western Paleotethyan imprints are documented near Moesia (Carpathian-Balkans, Rhodopes, Strandja, and North Dobrogea), including Hellenides and Pontides, where the Cimmerian structures are most prominent. Prior to the onset of the Upper Triassic compression and the predating closure of Paleotethys, the two segments of north Gondwana, ‘Greater Adria’ (or Apulia/Adria/Dinarides) and Carpathian-Balkan north Gondwanan-type basements (Serbo-Macedonian/Supragetic/Getic vs. Danubian/Moesia), experienced the latest Devonian - early Carboniferous or “early Variscan” ophiolite-decorated suturing (ophiolites are in the case of Carpathian-Balkan suture). This initial stage of the Variscan collision was followed by the recurrent early Permian “late Variscan” accretionary-type amalgamation (granites and repeatedly intruded syenites; Getic basement). The effects of the asymmetrically continuing subduction on the polydeformed configuration of Dinarides and Carpathian-Balkans show, however, no explicit evidence that the Paleotethyan subduction was terminated by continental collision so that mixed Variscan-Cimmerian terranes continued to face an open ocean. Neither Cimmerian-type mélanges nor Permian-Triassic blueschists-to-eclogites are documented northwest of Aegean External Hellenides.
Despite a number of difficulties, the synthesis of stratigraphic, paleogeographic, geophysical, and scarce detrital zircon data yields a new configuration outlining the two branches of post-Variscan Paleotethys that coexisted across the Balkan Peninsula. The “southern or Dinarides suture branch” of western Paleotethys is outside the External Dinaride carbonate platform (beneath the Adriatic Sea). The second yet segmented “Alps-Carpathian-Balkan Paleotethyan northern branch” connected the Alps with the Serbo-Macedonian hinterland (reflected by the geometry of the Jurassic-Cretaceous successor Vardar Zone). By contrast, the central Serbo-Macedonian margin (“northern segment” of”Carpathian-Balkan Paleotethyan branch”) exhibits no evidence of intensive post-Variscan magmatism relative to the “southern Serbo-Macedonian/Rhodopes/Aegean” branch. While the subduction beneath the “northern Serbo-Macedonian segment” lacks evidence of tectonothermal activity between the Permian-Late Triassic, its “southern limb” (Rhodopes/Pelagonian massif/Inner Hellenides) overrode still active Permian-Triassic subduction/magmatic arc. However, the synthesis further shows that the Permian – Triassic tectonomagmatic developments, particularly the tectonothermal imprints embedded across the southern Serbo-Macedonian limb, are inherently mixed. The geochemical data show a combination of margin-related rifting and subduction-related geochemical signatures. These marginal developments yielded several early Alpine continental rift basins followed by the formation of Triassic ophiolites, whereby the hinterland interior developed N-S-directed carbonate platform-type basins. The successor closure of the northward-directed Permian – Late Triassic Paleotethys was by the collision of the Cimmerian segment/magmatic arc along the periphery of Eurasia(Moesia). The Early Cimmerian collision depicted by the ultra-high-pressure metamorphic event in Rhodopes produced the Late Triassic deformation spreading across the Carpathian-Balkan-Rhodopes-Strandja interior. This Middle-Late Triassic Paleotethyan closure and subsequent “Early Cimmerian Orogeny” affected the early Alpine incipient rift basins (Volvi-Therma in western Rhodopes/southern Serbo-Macedonian). “Early Cimmerian Orogeny” additionally interrupted the development of the interior carbonate platform (Getic; eastern Serbia).
•Paleotethys Ocean superseded Variscan closure in Dinarides and partially in Carpathian-Balkan-Hellenide-Strandja areas;•With a few exceptions, remnant Paleotethys left neither Triassic mélanges nor metamorphic imprints of the Triassic age;•Adria/Apulia Cimmerian-type closure is associated with the first (External) Dinarides subduction zone (“Dinaride branch”);•“Northern” Paleotethyan Serbo-Macedonian/Getic hinterland carries the imprints of the “late Variscan event”;•“Late Variscan event” event is in connection with the terminal stage of Paleotethyan subduction (Permian);•Serbo-Macedonian/Rhodope/Pelagonides/Strandja was the upper lithospheric plate above the second Triassic or “southern Serbo-Macedonian” Paleotethyan subduction zone branch.
The study of aquifers of the Lece andesite complex (LAC) and its surroundings yielded a new procedural stepwise analysis that allowed the assessment of the origin of elements, particularly in areas ...affected by both anthropogenic and natural influences. The methodology uses the mineralogical composition of the rocks, including the elements available in rocks and groundwater. This study analyzes the element ratios B/Cl−, Na+/Ca2+, Ca2+/Mg2+, HCO3−/Cl−, and Na+/Na+ + Cl−; the correlations are coupled with a statistical analysis. In addition to reevaluating the already published water content, we provide an important new dataset. The results show that the main source of the water contamination with the elements B, F, U, As, Cu, Fe, Zn, Co, and Ni is the processes occurring at the contact between the groundwaters and non-altered/altered (propylitized) andesite rocks. This is also observed in the waters extracted from crystalline schists. The results may help develop an efficient use and assessment of the qualitative water potential of the LAC reservoirs. Similarly, the results highlight the applicability of the groundwaters, facilitating their regional research and use, further encouraging new initiatives for the preservation and protection of human and animal health.
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