Mineralogical mosaics from the Carpathian–Pannonian region 6

The Carpathian–Pannonian Region (CPR), including Austria, Slovakia, Hungary, Croatia, Serbia, Romania, and Ukraine, exhibits significant seismic activity, necessitating detailed crustal studies. Despite recent improvements in understanding CPR's crustal structure, it remains poorly known. Here, we applied improved autocorrelation of the P‐wave coda for the first time in CPR to image the Moho and Vp/Vs ratio. We present Moho depth estimates beneath 231 broadband seismic stations using autocorrelation of teleseismic P‐wave coda. Our results indicate a shallow Moho beneath the Pannonian, Vienna, and Danube basins, with depths between 20 and 30 km, while the deepest Moho is observed beneath the Southern Carpathians, Apuseni Mountains, and Southeast Carpathians, where it reaches depths of 45–55 km, deeper than previously reported. The shallower Moho beneath the basins indicates crustal thinning, while thicker Moho in neighboring mountain belts indicates orogenic thickening. Additionally, we estimated the crustal Vp/Vs ratio beneath 212 stations. The whole crust Vp/Vs ratio varies from 1.6 to 2.0, with notably high ratios (1.9 to 2.0) beneath the Pannonian, Vienna, and Danube basins. We also observed a Vp/Vs ratio greater than 1.80 beneath a few stations where mid‐crustal low‐velocity zones were detected. The average Vp/Vs ratio across the region is 1.76, slightly lower than the global average for continental crust. The lateral variations of Vp/Vs ratio indicate variation in crustal composition across CPR. These findings contribute valuable insights into the tectonics and crustal architecture of CPR.

The Zagros orogenic and metallogenic belt is characterized by the widespread occurrence of manganese and ferromanganese deposits. These deposits are spatially associated with radiolarian cherts and basaltic rocks, which cap the ophiolite sequences. The present work provides a review on the rare-earth element (REE) geochemistry coupled with major- and trace-element geochemical characteristics of the Nasirabad and Abadeh Tashk manganese deposits (associated with the Neyriz ophiolite), and Sorkhvand manganese deposit (associated with the Kermanshah ophiolite). These data are used to gain an insight into the primary ore-forming processes that control the deposition of manganese ores. All of the selected manganese deposits have consistently high Ba contents and low concentrations of trace elements (Co, Cu and Ni) with high Mn/Fe ratios typical of hydrothermal activity. A relatively low REE abundance, Lan/Ndn ratios (>3), and position on a Lan/Cen vs. Al2O3/(Al2O3 + Fe2O3) discrimination plot indicate a distal hydrothermal source for almost all of the selected manganese deposits. Most of the deposits are characterized by Ceanom < –0.1 which reflects the prevailing oxidative conditions during the deposition of manganese ores. Importantly, this is consistent with the occurrence of non-sulfide oxic Mn mineralization in all the manganese deposits of the Zagros orogeny. The comparison of the Sorkhvand, Abadeh Tashk and Nasirabad manganese deposits with other manganese deposits elsewhere in the world indicates that major- and trace-element characteristics, as well as the REE composition of the Zagros manganese deposits are analogous to those typical of hydrothermal deposits.

Mts. Kalnik and Požeska gora volcaniclastic sequences hold valuable information concerning the Miocene syn-rift evolution of the North Croatian Basin, and the evolution of the Carpathian–Pannonian Region and the Central Paratethys. We present volcanological, high-precision geochronological, and compositional data of volcanic glass to constrain their tephrochronology, magmatic provenance, and timing of the initial Central Paratethys flooding of the North Croatian Basin. Based on CA-ID-TIMS U–Pb zircon ages (18.060 ± 0.023 Ma for Mt. Kalnik and 15.345 ± 0.020 Ma for Mt. Požeska gora) and coeval 40Ar/39Ar sanidine ages (18.14 ± 0.38 Ma and 18.25 ± 0.38 Ma for Mt. Kalnik and 15.34 ± 0.32 Ma and 15.43 ± 0.32 Ma for Mt. Požeska gora), Mt. Kalnik rhyolitic massive ignimbrites and Mt. Požeska gora rhyolitic primary volcaniclastic turbidites are coeval with Carpathian–Pannonian Region Miocene post-collisional silicic volcanism, which was caused by lithospheric thinning of the Pannonian Basin. Their affiliation to Carpathian–Pannonian Region magmatic activity is supported by their subduction-related geochemical signatures. Although Mts. Kalnik and Požeska gora volcaniclastics are coeval with the Bukkalja Volcanic Field Csv-2 rhyolitic ignimbrites, North Alpine Foreland Basin, Styrian Basin, Vienna Basin, and Dinaride Lake System bentonites and volcaniclastic deposits, reliable tephrochronological interpretations based on comparison of volcanic glass geochemical composition are not possible due to a lack of data and/or methodological discrepancies. Our new high-precision geochronology data prove that the initial Middle Miocene (Badenian) marine flooding of parts of the North Croatian Basin occurred at least ~ 0.35 Ma (during the NN4 Zone) before the generally accepted ~ 15 Ma maximum flooding age at the basin scale, calibrating the timing of the onset of the widespread “mid-Langhian” Central Paratethys flooding.

Carboniferous–Permian magmatic rocks are common in the Carpathian–Pannonian region, whereas Cambrian–Devonian (meta)igneous associations are less frequent and not yet confirmed by radiometric data in the basement of the Pannonian Basin. The major goal of this study was to constrain Ordovician zircon U–Pb ages from (meta)igneous rocks representing three prospective study areas in the inner Carpathian–Pannonian region: the Bihor Mts (Apuseni Mts, Tisza–Dacia Mega-unit), the eastern Mecsek Mts (southern Transdanubia, Tisza–Dacia Mega-unit), and the Balaton Highland (central Transdanubia, ALCAPA Mega-unit). Metagranitoids from the Bihor Mts yielded an Early Ordovician protolith age of 478.0 +3.2/−2.5 Ma which, supported by bulk-rock geochemistry and deformation, suggests they belong to the ~495–477 Ma extensional bimodal magmatism of the Biharia terrane and may be related to back-arc rifting along the northeastern margin of Gondwana. These rocks were later overprinted by multiple Alpine shearing events within the Highiş–Biharia Shear Zone. A Middle Ordovician age of 464.8 +3.0/−3.1 Ma, from one of the lower magmatic sections of the Kékkút–4 borehole in the Balaton Highland, is most plausibly attributed to the Alsóörs Metarhyolite and identifies it as the oldest known igneous formation within Hungary confirmed by numerical age data. Contrary to being overlain by Silurian slate, monzonites from the Szalatnak–3 borehole in the eastern Mecsek Mts yielded a Carboniferous age of 332.7 +2.1/−1.6 Ma. These subvolcanic rocks exhibit alkaline, apparently shoshonitic characteristics and are slightly younger than the nearby I-type Mórágy Metagranite (~354–338 Ma). Supported by bulk-rock geochemical similarities, this may indicate that the two formations originated along the same active continental margin, representing different phases of a complex Variscan geodynamic evolution: subduction followed by post-collisional extension.

Further mosaic-like data were recorded on the mineral occurrences of the Carpathian–Pannonian region in this fifth member of the series arranged by countries and localities. Each “mosaic” contains a concise mineral description, mainly based on XRPD, SEM-EDX and EPMA measurements and a concise description of the mineral paragenesis. Some minerals are first-time descriptions from the entire discussed region, but all are newly documented occurrences for at least the described locality. From Hungary humboldtine and weddellite are described from the coalbed of Csordakút (Bicske), and data from Sr-rich and other Aluminium Phosphate Sulphate (APS) minerals from the ore mineralization of the Lahóca Hill at Recsk are also reported. Chemical data of Mg-rich tourmaline from the Harghita volcanic ridge are given, and also kyrgyzstanite is described from the ore mineralization of Baia Sprie, Romania. From Slovakia Na-containing sulphates (kröhnkite, ferrinatrite, tamarugite) from the ore mineralization of Farbište (Poniky) and an arsenate (bariopharmacosiderite) from the ore mineralization of Rožňava are also introduced.

Geochemistry and tectonic development of Cenozoic magmatism in the Carpathian–Pannonian region

This is the fourth paper presenting new mosaic-like mineralogical data from the Carpathian–Pannonian region. Data are arranged by countries and localities. Every section gives a description (including XRPD, EMPA and SEM-EDX results) of the minerals and a concise description of their parageneses. Every discussed mineral is first described from the given locality and in many times even from the whole region.From Hungary the following minerals are reported: freieslebenite and beaverite-(Cu) from the Rudabánya ore deposit, planerite–aheylite–faustite–turquoise solid-solution members from the Parádfürdő ore deposit.From Romania the following minerals are identified: conichalcite (with high Pb content, conichalcite–duftite solid solution), duftite and mottramite–duftite solid-solutions from the Băiţa Bihor ore deposit, pseudomalachite pseudomorph after azurite as well as vauquelinite from the Ocna de Fier ore deposit.From Slovakia the following minerals are described: axinite-(Fe) from the Maglovec diorite-porphyrite quarry, bultfonteinite from the Vechec andesite quarry and botallackite from the Dobšiná ore deposit.

We use ambient noise tomography to investigate the crust and uppermost mantle structure beneath the Carpathian-Pannonian region of Central Europe. Over 7500 Rayleigh wave empirical Green's functions are derived from interstation cross-correlations of vertical component ambient seismic noise recordings (2005-2011) using a temporary network of 54 stations deployed during the South Carpathian Project (2009-2011), 56 temporary stations deployed in the Carpathian Basins Project (2005-2007) and 100 permanent and regional broad-band stations. Rayleigh wave group velocity dispersion curves (4-40 s) are determined using the multiple-filter analysis technique. Group velocity maps are computed on a grid of 0.2° × 0.2° from a non-linear 2-D tomographic inversion using the subspace method. We then inverted the group velocity maps for the 3-D shear wave velocity structure of the crust and uppermost mantle beneath the region. Our shear wave velocity model provides a uniquely complete and relatively high-resolution view of the crustal structure in the Carpathian-Pannonian region, which in general is validated by comparison with previous studies using other methods to probe the crustal structure. At shallow depths ( 30 km are relatively fast, presumably related to shallowing of the Moho consequent on the extensional history of the Pannonian region.

Provenance and depositional environment of Middle Miocene silicic volcaniclastic deposits from Mt. Medvednica (North Croatian Basin, Carpathian-Pannonian Region)

Metallogeny and temporal–spatial distribution of manganese mineralizations in Iran: Implications for future exploration

Neogene–Quaternary magmatism and geodynamics in the Carpathian–Pannonian region: a synthesis

Based on a self-consistent K–Ar database completed with up-to-date geochronological information, this review paper addresses the general time–space evolution of Neogene magmatism in the Carpathian–Pannonian region, aiming at identifying significant patterns and trends. Grouped according to petrochemical criteria (felsic and intermediate calc-alkaline, alkaline) and major geotectonic units (Carpathian and intra-Carpathian, in turn divided into ALCAPA and TISZA-DACIA lithospheric blocks), the dated rocks reveal distinct evolution patterns. The intra-Carpathian area is characterized by (1) scattered, areal Eastward shifting magmatism, more developed on the ALCAPA block, involving felsic and intermediate calc-alkaline magmas in the early stage of evolution (21–7 My) and alkaline magmas in the later stages (11 to < 1 My), and (2) long-lasting magmatic activity spatially focused in an area ca. 200 km across located on the ALCAPA block, shifting in time from felsic to intermediate calc-alkaline and finally to alkaline compositions. We suggest that a mantle plume-type thermal anomaly was acting at the site of focused magmatism contributing to the development of higher volume areal-type magmatism in the same block, as compared with the later activated colder and more brittle TISZA-DACIA block. The Carpathian magmatism in turn displays two distinct time–space evolution patterns: (1) a long-lasting and slowly eastward migrating intermediate calc-alkaline magmatic front, active in the 15–9 My time interval along most of the Carpathian thrust-and-fold belt, generated in a subduction environment, and (2) a time-transient magmatism along the South-easternmost Carpathian segment, in the 11 to < 0.1 Ma time interval, whose purely subduction-related origin is questionable. Beyond these evolution patterns, two regional CPR-wide trends have also been identified: (1) the general Eastward shift of magmatic activity in time, irrespective of the chemical type, and (2) the convergence of magmatism in both time and space towards the South-eastern corner of the CPR (i.e. the Carpathian bend area in Romania), currently the geodynamically most active (and most hazardous) area of the whole CPR, including the Vrancea seismic structure. Eastward directed asthenospheric flow, possibly related to the inferred mantle plume responsible for the focused time-persistent volcanism on the ALCAPA block, might be considered as being at the origin of these evolutionary trends.

Geochemical response of magmas to Neogene–Quaternary continental collision in the Carpathian–Pannonian region: A review

Post-collisional Tertiary–Quaternary mafic alkalic magmatism in the Carpathian–Pannonian region: a review

The Nógrád–Gömör Volcanic Field is one of the most thoroughly studied upper mantle xenolith-bearing localities in the Carpathian–Pannonian region. Dozens of upper mantle xenoliths collected there have been investigated from various aspects in the past decades. Major element compositions of upper mantle xenoliths available in scientific papers on the Nógrád–Gömör xenoliths were extracted to build a database. This database includes the geochemical composition of the rock-forming minerals (olivine, pyroxenes, spinel) of 112 upper mantle xenoliths. Using the data compiled in this database, we applied the CluStress algorithm to perform cluster analysis. The results led to the division of 2 supergroups (I and II) and 17 groups within them. Supergroup I was split into two subgroups (Supergroup I/a and I/b). The xenoliths of Supergroup I/a and I/b are distinguished by their orthopyroxene/clinopyroxene modal composition ratios (mainly &gt;1.5 and &lt;1, respectively) as well as their olivine Mg-numbers (dominantly &gt;0.89 and &lt;0.89, respectively). Most of the xenoliths (~50% of all classified xenoliths) were sorted into Group 1 within Supergroup I/a, and they appear at almost all xenolith-bearing localities in the Nógrád–Gömör. The Group 1 xenoliths exhibit narrow compositional ranges regarding their major element relationships. Due to their common occurence and spatial distribution, these rocks were considered to represent an ambient lithospheric mantle under­neath the study area. The geochemical characteristics of the other groups allowed their linking to different events described in former scientific works. At least 11 out of the 17 distinguished groups (i.e. ~35% of the classified xenoliths) are strongly related to the Neogene alkali basaltic volcanism. This suggests that the pre-Neogene rootzones of volcanic fields in the Carpathian–Pannonian region were significantly modified by intensive melt-rock reactions between upward migrating basaltic melts and wall rocks, which took place in the last ~10 million years.