Földtani Közlöny

Szederkényi Tibor köszöntése a munkássága előtt tisztelgő Földtani Közlöny-kötet megjelenése alkalmából

2025-10-15T17:42:54+00:00

Dr. Tibor Szederkényi, a professor at the University of Szeged and later at the University of Pécs, celebrated his 90th birthday in September 2024. His detailed biography, published on the occasion of his 70th birthday (Kóbor & Pál-Molnár 2004), carefully details his vibrant career, which spans from assessing the rare element potential of South Transdanubia to leading mapping expeditions in New Zealand and Canada, as well as conducting in-depth petrological studies of the metamorphic basement of the Great Plain. The authors acknowledge his contributions with the articles in this volume. The professor is a distinguished representative of a generation that learned, observed, and taught the Earth as a complex interconnected entity, rather than a collection of disjointed sub-sciences covering increasingly smaller fields.

Elastic thermobarometry – a methodological overview

2025-10-15T17:42:54+00:00

The study of metamorphic rocks is a key to understand the ongoing plate tectonic processes, as they commonly preserve the record of several episodes of their geological evolution, like chemical or mechanical equilibrium, metamorphic reactions, fluid-rock interaction over millions (or tens of millions) of years. Inclusions (fluid, melt and mineral inclusions) entrapped in rock-forming minerals preserve chemical compositions and physical states that allow direct study of processes that occurred at higher pressures and/or temperatures, even in the subduction zone. Mineral inclusions are common in metamorphic minerals and can be trapped over a wide range of pressure and temperature (P-T) conditions during the growth of the host mineral and can be used to reconstruct the trapping conditions. The solid crystal inclusions trapped within the rock-forming minerals during growth experience different magnitudes of volume change due to their different elastic compressibility and thermal expansion coefficients. The host and inclusion minerals are therefore subject to different volume changes during the subsequent P-T path (from entrapment at depth to surface exposure). This „passive” differential volume change result in stress buildup between the host mineral and the inclusion that is characteristic of trapping P-T. Therefore, some host-mineral inclusion pairs can be used as barometers (e.g., quartz in garnets) because of their different mechanical properties, while other pairs can be used as thermometers (zircon in garnet). The residual stress can be determined by carrying out Raman spectroscopic analyses or single-crystal X-ray diffraction, given the appropriate material constants and equations of states, which can be used to determine the trapping conditions (entrapment isomeke). Regarding its increasingly wide application, this overview presents the methodological aspects of elastic thermobarometry based on Raman spectroscopy measurements that can be applied to reconstruct P-T evolution not only of metamorphic, but magmatic rocks as well.

Architecture of the metamorphic Algyő High (SE Pannonian Basin) based on lithological interpretation of natural gamma-ray logs

2025-10-15T17:42:55+00:00

The metamorphic basement of the Algyő High, located in the Pannonian Basin, is a reservoir unit within an important hydrocarbon system in the SE part of Hungary. Over the past century, more than 100 exploration wells have reached the basement in the area, providing a substantial number of core samples and well-log data for analysis. This study reviewed and analysed well-log data from these boreholes to establish correlations between primary metamorphic rock types and wireline logs, enhancing the spatial information derived from core samples. For geophysical–lithological correlation, natural gamma-ray intensity logs were considered the most suitable for this area. These logs are sensitive to lithological variations and are effective for large-scale lithological identification. Our results reveal significant lithological variations within the basement, reflected in variations in gamma-ray intensities. The well-log data for the entire area confirm that the basement of the Algyő High comprises three major blocks. The northwest and southeast portions of the area, dominated by garnet–kyanite gneiss, exhibit higher gamma intensities compared to the central region, which is characterised by low-grade metamorphic rocks and lower gamma intensities. The analysis of the entire region revealed anomalies in gamma intensities in the southeastern part. Focusing on this area, the petrographic and well-log data indicated that the basement is dominated by garnet–kyanite gneiss with zones of garnetiferous amphibolite with low gamma intensities. Within the gneiss mass, metagranite with higher gamma intensities was identified. This rock type is interpreted as young granite/granodiorite intrusive dykes. These intrusions may have affected the mineralogical and chemical composition of the host gneiss, resulting in metasomatised zones within the garnet–kyanite gneiss realm, which are interpreted as metasomatised gneiss. The analysis of wireline data in conjunction with core samples provides new insights into the complex lithological composition and structural evolution of the area.

Fracture-controlled paleofluid migration in the Óbánya Valley (Eastern Mecsek)

2025-10-15T18:48:00+00:00

Over the past two decades, traces of hydrocarbon-bearing paleofluid migration have been detected in several Triassic and Jurassic formations in the Mecsek Mountains. This study focuses on the easternmost known hydrocarbon occurrence, represented by a partially cemented fracture network in the Óbánya Valley, with the aim of reconstructing the formation conditions of the fracture system. Classical structural geological methods were employed to characterize the evolution of this fracture system. As a result, two distinct deformation phases were identified: a) a folding event, and b) a subsequent left-lateral displacement. Theoretical orientation of fractures associated with the observed folds were determined and compared with field measurements. This approach allowed us to define several fault orientations and fault breccias, as well as to link calcite veins to a folding process. Fluid inclusion petrography revealed the presence of both aqueous and hydrocarbon-bearing fluid inclusions within six distinct vein generations. These findings suggest that hydrocarbon-bearing fluids migrated along one of the four deformation-related fracture sets in this fracture system. Although the nature of the fluid inclusion assemblages provides only limited constraints on the thermal conditions during fluid migration, several vein structures suggest episodic increases in fluid pressure during the system’s evolution.

Data on the Neogene activity of the Mecsek Mountains frontal fault zone in Pécs (SW Hungary)

2025-10-15T17:42:56+00:00

The Mecsekalja Dislocation Zone forming the southern – southeastern margin of the Mecsek Mts. is a complex fault zone that reactivated several times. We studied examining temporary outcrops within the fault zone in the city of Pécs to gain information on Neogene tectonic activity. We constrained the age of the exposed rocks using lithological analogies, micropaleontological investigations and mollusc biostratigraphy, and identified lower Sarmatian sediments as well as those deposited in two time intervals within the Pannonian. The observed deformations – tilting, folds, mostly reverse faults, basement overthrusting – refer to NNW–SSE compression. Induced by a relatively stable stress field, one or two early Sarmatian and three or four later deformation events could be identified: before, during and after the late Pannonian sedimentation (8–6.5 Ma). In the Pannonian, movements certainly took place after 10–9.6 Ma, but Sarmatian sediments possibly deformed (also) before that time. While in the Sarmatian most of the Pannonian Basin underwent active rifting, the Mecsek experienced compression. No extensional deformation could be detected in the area in the last 10 million years, basin inversion seems to have started here in the first half of the Pannonian age. The deformation of resistant coarse sediment in the western part of Pécs could influence modern topography.

Discussion paper on boosting geothermal energy use

2025-10-15T17:42:56+00:00

Increasing the use of geothermal energy is crucial to the energy transition, particularly in the heating and cooling sector. Hungary's favourable geological conditions and well-developed district heating network provide an excellent basis for this. However, as stated in the Hungarian State Audit Office's report on this topic, the legal environment needs to be changed. I have formulated my proposed amendments with this in mind.

„The sum of the matter is this: what needs to be improved or changed in our laws because they provide the impetus for the development of our society. Examining this will be the focus of my proposal.” (Széchenyi 1833)

In memoriam Mártonné Szalay Emőke

2025-10-15T17:42:57+00:00

It may be out of the blue after a decade of not hearing a word from me. I have many things I would like to tell you. Having a coffee together for the very last time would be amazing. We would sit once more at the small desk in the tiny room functioning both as a sample preparation place, kitchen, and dining room of the first, and up to date, only Paleomagnetic Laboratory in Hungary – your creation, without doubt something to be proud of, and maybe a second home for a lifetime. The smell of the freshly made coffee from a particular brand (your favorite and the only type that is “allowed” in the laboratory) fills the air. The cups are already on the table. Let's have a short break. (see more in the PDF attached)

In memoriam Csath Béla

2025-10-15T17:42:57+00:00

Csath Béla elemi és középiskolai tanulmányait Zalaegerszegen végezte el. A II. világháborút követően nyugati fogságba került, szabadulása után Zalaegerszegen, a Deák Ferenc Gimnáziumban érettségizett. 1946 szeptemberében kezdte meg bányamérnöki tanulmányait Sopronban, a József Nádor Műszaki és Gazdaságtudományi Egyetemen, de a diplomáját már a Miskolci Nehézipari Egyetemen kapta meg 1951. szeptember 14-én. Jubileumi bánya mérnöki díszoklevelei: aranydiploma (2001), gyémántdiploma (2011), vasoklevél (2016), rubinoklevél (2021). (folytatás a PDF)

Események, rendezvények, személyi hírek, könyvismertetések

2025-10-15T17:42:58+00:00

Események, rendezvények

Geotúrák a Művészetek Völgye Fesztiválon
Földtani alapismeretek hátrányos helyzetű gyermekeknek az Angyaljárat Közalapítvány táborában

Személyi hírek

(részletek a PDF-ben)