Geološki anali Balkanskoga poluostrva

Indentation‑induced deformation in the Serbian Carpathians: a structural and kinematic study in the TMC basin and the Lower Getic Unit

Nikola Ranđelovic — 2025-12-26

A field structural study was performed in the Late Cretaceous Timok Magmatic Complex (TMC) basin and the underlying Lower Getic unit to improve understanding of post‐Eocene tectonic evolution of the Serbian Carpathians. Our study demonstrates that Oligocene – Middle Miocene deformation is recorded in the TMC Basin, and it is characterized by strain partitioning between normal faults accommodating N–S to NW–SE extension and two distinct groups of strike‐slip faults. In the central parts of the TMC basin, these structures controlled the opening of several Miocene intra‐montane pull-apart basins. Southwards, the fault system change to a right lateral fault with a horse‐tail geometry. Our observations indicate that Oligocene – Middle Miocene structures from the TMC and neighbouring units are an integral part of the previously defined Circum‐Moesian Fault System that accommodated along‐strike changes in the collisional mechanics of the Carpathians.

Current understanding of the Sava Zone of the Balkans: a magmatic perspective

Kristijan Sokol — 2025-12-26

The Sava Zone (SZ) forms a key tectonic boundary between Europe derived and Adria‐derived continental units in the central Balkans and hosts a discontinuous belt of Late Cretaceous volcanic and plutonic rocks whose geo dynamic significance remains strongly debated. Traditional interpretations viewed this belt as the youngest remnant of the Neotethyan Ocean, implying an oceanic environment and ophiolitic affinities. However, recent studies challenge this interpretation suggesting that much of the SZ magmatism has intracontinental origins. This revised perspective indicates that these magmatic rocks may not be associated with oceanic subduction, as previously thought, but rather with the tectono‐magmatic evolution of the European (Tisza‐Dacia) and Adria plates.

In this review we synthesize available petrological, geochemical, and geo chronological data from all major localities where Upper Cretaceous magmatic rocks occur along the broader area of Sava Zone. Magmatic activity, con strained to ca. 87–76 Ma, spans tholeiitic to alkaline basalts and composition ally diverse felsic rocks. Two contrasting magmatic domains are evident. Adria‐side localities host tholeiitic to transitional basalts with N‐ to E‐MORB like signatures derived from a relatively depleted spinel‐bearing mantle. Euro pean‐side occurrences contain enriched within‐plate basalts and lamprophyres approaching OIB‐like characteristics, requiring melting of a metasomatized lithospheric mantle extending into the garnet–spinel transition field. In our view, this asymmetry reflects lateral mantle heterogeneity rather than funda mentally different tectonic environments. The acidic rocks occurring within the European‐affinity blocks display considerably greater diversity, including A1, A2, and S‐type granitoid compositions, whereas the acidic rocks in the Dinarides (Adriatic plate) are predominantly restricted to the A2 subtype. Regionally, Sava Zone magmatism was coeval with ‐ but genetically distinct from ‐ the Apuseni–Banat‐Timok‐Sredna Gora magmatic and metallogenic belt. Whereas the latter may have formed with or without invoking an actively sub ducting oceanic domain (e.g., the proposed “Sava Ocean”), the Sava Zone mag mas in our view reflect lithospheric thinning, transtension, and mantle upwelling driven by slab rollback. These findings indicate that the Sava Zone records the transition from subduction‐driven to post‐collisional tectonics during the final reorganization of the Neotethyan margin. We therefore propose redefining this system as part of the Central Balkan Late Cretaceous Magmatic Province ‐ an intracontinental belt marking the waning stages of Tethyan closure.

Biostratigraphy and depositional setting of the carbonate unit within the upper part of the Maastrichtian Tanjero Formation in the Khanaqa Village, Imbrication Zone, NE Iraq Kurdistan region

Arkan O. Sharazwri — 2025-12-26

This study investigates the biostratigraphy and depositional environment of a carbonate unit located in the upper part of the Tanjero Formation, exposed in Khanaqa Village within the Imbrication Zone of northeastern Iraq. The unit comprises approximately three meters of massive and thick‐bedded, sandy, yellowish‐grey, fossiliferous limestone, with thin intercalations of marly bioclastic limestone in its lower section. Petrographic analysis, based on 18 thin sections, reveals a diverse assemblage of shallow‐marine macrofossils and microfossils, including corals, rudists, various benthic foraminifera, and algae. Microfacies analysis identified three dominant microfacies, further subdivided into eight types, all characteristic of reefal environments. The benthic foraminiferal assemblages indicate a Maastrichtian age for the studied deposits. Based on lithological, petrographic, and paleontological evidence, the overall characteristics of the carbonate unit are more consistent with those of the Maastrichtian Aqra Formation. The occurrence of the Aqra Formation within the upper part of the Tanjero Formation in the studied area reflects a significant sea‐level change, concurrent with tectonic activity in the Tanjero Basin during the latest Cretaceous period in the Kurdistan Region of northern Iraq.

Mineralogical and structural characterization of zeolitic tuff from the Slanci deposit, Serbia

Katarina M. Mihajlović — 2025-12-26

Lake Miocene deposits located east of Belgrade in the Danube bend, around Veliko Selo and Slanci, are rich in zeolitic tuffs of the heulandite type. This paper presents mineralogical and structural investigations of zeolitic tuffs in which the dominant phase is Ca‐heulandite with a Si/Al ratio of 3.78. Volcanic glass and biogenic amorphous silica are present as accompanying components. Quantitative X‐ray powder analysis determined the following mineral composition: heulandite (85.1%), quartz (1.9%), muscovite (5.9%), albite (6.6%), orthoclase (0.6%) and calcite (0.21%). The structure was refined in the space group C2/m, with a disordered distribution of Al and Si within the tetrahedral framework. The following methods were applied: powder X‐ray diffraction on a polycrystalline sample (XRPD), scanning electron microscopy and energy-dispersive X‐ray spectroscopy (SEM/EDS), and differential thermal and thermogravimetric analysis (DTA/DTG/TG).

Structural data acquisition in a cave using smartphone LiDAR and Virtual Compass

Igor Ivanovski — 2025-12-26

Three‐dimensional (3D) modeling has become a preferred approach for acquiring high‐accuracy spatial data efficiently. While terrestrial laser scanning (TLS) delivers high‐quality point clouds, its cost often motivates the search for affordable alternatives. In structural geology, robust rock‐mass characterization requires geometric information from both intact rock and its discontinuities; point‐cloud–based surface analysis enables estimation of key parameters such as dip and dip direction. Recent smartphones equipped with LiDAR sensors offer a low‐cost means to obtain 3D point clouds suitable for such analyses. This study evaluates the capability of an iPhone Pro LiDAR scanner to acquire structural data from planar features inside a cave in southern part of Macedonia and compares the results with conventional compass measurements. It represents the next step in verification of this methodology, previously performed on various outcrops in Macedonia. The 3D point clouds were processed in CloudCompare software, and structural orientations were derived using its Virtual Compass tool. The smartphone‐based measurements on a 3D point cloud using Virtual Compass, show a highly promising agreement with the geological compass data, indicating that mobile LiDAR can provide a reliable and efficient complement to traditional field methods for cave environments and similarly constrained settings.

Corrigendum to “The Bulog Formation in the type area (Sarajevo) and related Middle and Late Triassic open‑marine sedimentary successions in the Dinarides of Bosnia and Herzegovina” [Geološki anali Balkanskoga poluostrva (2025) 86/1, 1‑67]

Milan Sudar — 2025-12-26

Corrigendum to: The Bulog Formation in the type area (Sarajevo) and related Middle and Late Triassic open‐marine sedimentary successions in the Dinarides of Bosnia and Herzegovina.

Authors: MILAN SUDAR, HANS‐JÜRGEN GAWLICK & FERID SKOPLJAK

Published in: Geološki anali Balkanskoga poluostrva, VOL. 86, NO. 1 (2025), pp. 1–67 https://doi.org/10.2298/GABP241216002S

For unknown reasons an old version of Figure 23 was published. An emended version of Figure 23 is provided below. There is no change in the caption of this figure. References cited are printed in the published version, Vol. 86, No. 1 (2025), pp. 1‐67.