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A review of Paleogene-early Miocene igneous rocks of the Alpine-Carpathian-Pannonian -Dinaric region is presented in this paper. We attempt to reveal the geodynamic link between Paleogene-early Miocene igneous rocks of the Mid-Hungarian zone and those of the Alps and Dinarides. Our summary suggests that Paleogene-early Miocene igneous rocks of all these areas were formed along a single, subduction-related magmatic arc. The study also highlights orthopyroxene-rich websterite mantle xenoliths from west Hungary and east Serbia that were formed in the vicinity of a subducted slab. We discuss the location and polarity of all potential subduction zones of the area that may account for the igneous rocks and orthopyroxene-rich mantle rocks. However, results of seismic tomography on subducted slabs beneath the studied area combined with geological data demonstrate that igneous rocks and mantle rocks cannot be explained by the same subduction process. We propose that the Paleogene-early Miocene arc was mainly generated by the Budva-Pindos subduction zone, subordinately by Penninic subduction, whereas mantle rocks were possibly formed in the vicinity of the older Vardar subduction zone. Continental blocks possibly moved together with their mantle lithosphere. The present diverging shape of the proposed arc has been achieved by considerable shear and rotations of those lithospheric blocks.

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This study focuses on particle size effect on monomineralic powders recorded using attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy. Six particle size fractions of quartz, feldspar, calcite, and dolomite were prepared (<2, 2-4, 4-8, 8-16, 16-32, and 32-63 µm). It is found that the width, intensity, and area of bands in the ATR FT-IR spectra of minerals have explicit dependence on the particle size. As particle size increases, the intensity and area of IR bands usually decrease while the width of bands increases. The band positions usually shifted to higher wavenumbers with decreasing particle size. Infrared spectra of minerals are the most intensive in the particle size fraction of 2-4 µm. However, if the particle size is very small (<2 µm), due to the wavelength and penetration depth of the IR light, intensity decreases. Therefore, the quantity of very fine-grained minerals may be underestimated compared to the coarser phases. A nonlinear regression analysis of the data indicated that the average coefficients and indices of the power trend line equation imply a very simplistic relationship between median particle diameter and absorbance at a given wavenumber. It is concluded that when powder samples with substantially different particle size are compared, as in regression analysis for modal predictions using ATR FT-IR, it is also important to report the grain size distribution or surface area of samples. The band area of water (3000-3620 cm) is similar in each mineral fraction, except for the particles below 2 µm. It indicates that the finest particles could have disproportionately more water adsorbed on their larger surface area. Thus, these higher wavenumbers of the ATR FT-IR spectra may be more sensitive to this spectral interference if the number of particles below 2 µm is considerable. It is also concluded that at least a proportion of the moisture could be very adhesive to the particles due to the band shift towards lower wavenumbers in the IR range of 3000-3620 cm.

To better understand the evolution and present‐day tectonics of the Carpathian‐Pannonian Region (CPR), we characterize the upper mantle anisotropic structure. We present a shear wave splitting analysis from teleseismic events recorded at the Carpathian Basin Project and permanent stations located in the CPR. The results show a large‐scale uniform NW‐SE fast orientation under the entire CPR. Compared with the complexity of geologic structures, the anisotropy expresses a relatively simple pattern of deformation. We attribute this anisotropy to an asthenospheric origin and interpret it as flow‐induced alignment within the upper mantle. We also observe a few measurements depicting NE‐SW fast orientation in line with the Mid‐Hungarian Shear Zone. This suggests the likely contribution of either lithosphere or northeastward flow into a slab gap under the northern Dinarides. We observe splitting delay times on average of 1 s, showing noticeable change (60%) in the middle Pannonian basin. This change correlates well with the variation in the thickness of low‐velocity zones that were previously imaged between a depth of 75 and 400 km by velocity tomography. In order to evaluate the relation between anisotropy and tectonics, we compare our data with the tectonic models that have so far been suggested to explain the evolution and current‐stage tectonics of the region. We present here a plausible tectonic model responsible for the NW‐SE anisotropy within the asthenospheric mantle. In this model, NW‐SE deformation is mainly generated in a northeastward compressional tectonic regime acting in a wide region between the Adriatic microplate and the East European platform.

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Five spinel lherzolite xenoliths hosted in Neogene alkali basalts from the marginal parts of the Pannonian Basin (Styrian Basin in Austria and Persani Mts. in the Eastern Transylvanian Basin, Romania) contain orthopyroxene–clinopyroxene–spinel clusters, which are believed to represent former garnet in lherzolitic mantle material. ‘Palaeo’ equilibrium pressure of this former garnet lherzolite was estimated to be equivalent to depths of 90–120 km using calculated garnet compositions and measured orthopyroxene compositions from the clusters. ‘Neo’ equilibrium pressures of the xenoliths indicate depths of 55–65 km, suggesting c. 50–60 km uprise of the mantle section represented by these xenoliths. This petrological result confirms the observations from previous geophysical studies that significant mantle uplift has occurred beneath the Pannonian Basin.

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