Insight into the continental lithosphere using 3D geophysical and petrological modelling: An example from the Novohrad-Gemer region (Pannonian Basin, Slovakia-Hungary)

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F25%3A00618601" target="_blank" >RIV/67985530:_____/25:00618601 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S092181812500044X?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S092181812500044X?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.gloplacha.2025.104735" target="_blank" >10.1016/j.gloplacha.2025.104735</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Insight into the continental lithosphere using 3D geophysical and petrological modelling: An example from the Novohrad-Gemer region (Pannonian Basin, Slovakia-Hungary)

Popis výsledku v původním jazyce

Percolation of fluids and melts in the crust and the lithospheric mantle produces alteration zones with significantly disturbed physical properties, such as electrical resistivity and seismic velocity. The geophysical signatures of a metasomatized mantle include gravity responses as well because the modified modal and chemical compositions result in density changes. Here, we show how the local anomalous gravity field can be mapped in intraplate tectonic settings and interpreted using three-dimensional integrated modelling, involving intra-crustal structures, deep faults, and various mantle lithologies. The 3D interpretation performed using IGMAS+ software enables the integration of independent geo-datasets. Densities of near-surface (<5 km) bodies have been defined using laboratory measurements of surface and borehole rock samples and from well-logging. To calculate rock densities at greater depths, p-wave velocities have been transformed to in situ densities (rho), while the densities of the lower lithosphere have been determined using thermodynamic modelling constrained by the chemical composition of xenoliths brought to the surface by alkali basalts. Thermobarometric data on megacrysts helped constrain the vertical extent of mantle metasomatism. To elucidate the inherent ambiguity of the gravity method, several geologically reasonable models conforming to the observed gravity field are tested. Based on the proposed 3D lithospheric models, the following conclusions can be drawn regarding the northern margin of the Pannonian Basin: a) The thickness of Neogene volcanics and sediments is variable, ranging from 0 to 4 km, nb) TheHurbanovo-Diosjen ´ o-Darn ˝ o ´ fault zone is a steep and deeply penetrating first-order tectonic zone filled with lowdensity rocks in the upper crust and characterized by low-amplitude gravity anomalies and a maximum ofnmodified horizontal gradient amplitude, c) Garnet-bearing mafic rocks with a density of 3.1 g⋅cm− 3 are identifiednat the Conrad discontinuity, d) The subjacent lithospheric mantle is characterized by a sandwich structurenconsisting of a 9.0–9.5 km thick upper layer of mafic cumulates, a 12.0 km thick middle layer of the metasomatized mantle, and the wehrlitized mantle in a depth interval from 50 km to 77 km. Alternative models admit either a crustal Cadomian(?) segment with a density of 2.84 g cm− 3, with its upper boundary ranging from 10 to 18 km located beneath the Veporic unit, or a purely hypothetical eclogite layer with a density of 3.51 g⋅cm− 3 within the mantle. Such an interdisciplinary approach combining geophysical and petrological data is also applicable in other continental tectonic settings. Detection of crustal and mantle sources related to deep-seated deformation zones through specific geophysical patterns could play an important role in global lithosphere research.

Název v anglickém jazyce

Insight into the continental lithosphere using 3D geophysical and petrological modelling: An example from the Novohrad-Gemer region (Pannonian Basin, Slovakia-Hungary)

Popis výsledku anglicky

Percolation of fluids and melts in the crust and the lithospheric mantle produces alteration zones with significantly disturbed physical properties, such as electrical resistivity and seismic velocity. The geophysical signatures of a metasomatized mantle include gravity responses as well because the modified modal and chemical compositions result in density changes. Here, we show how the local anomalous gravity field can be mapped in intraplate tectonic settings and interpreted using three-dimensional integrated modelling, involving intra-crustal structures, deep faults, and various mantle lithologies. The 3D interpretation performed using IGMAS+ software enables the integration of independent geo-datasets. Densities of near-surface (<5 km) bodies have been defined using laboratory measurements of surface and borehole rock samples and from well-logging. To calculate rock densities at greater depths, p-wave velocities have been transformed to in situ densities (rho), while the densities of the lower lithosphere have been determined using thermodynamic modelling constrained by the chemical composition of xenoliths brought to the surface by alkali basalts. Thermobarometric data on megacrysts helped constrain the vertical extent of mantle metasomatism. To elucidate the inherent ambiguity of the gravity method, several geologically reasonable models conforming to the observed gravity field are tested. Based on the proposed 3D lithospheric models, the following conclusions can be drawn regarding the northern margin of the Pannonian Basin: a) The thickness of Neogene volcanics and sediments is variable, ranging from 0 to 4 km, nb) TheHurbanovo-Diosjen ´ o-Darn ˝ o ´ fault zone is a steep and deeply penetrating first-order tectonic zone filled with lowdensity rocks in the upper crust and characterized by low-amplitude gravity anomalies and a maximum ofnmodified horizontal gradient amplitude, c) Garnet-bearing mafic rocks with a density of 3.1 g⋅cm− 3 are identifiednat the Conrad discontinuity, d) The subjacent lithospheric mantle is characterized by a sandwich structurenconsisting of a 9.0–9.5 km thick upper layer of mafic cumulates, a 12.0 km thick middle layer of the metasomatized mantle, and the wehrlitized mantle in a depth interval from 50 km to 77 km. Alternative models admit either a crustal Cadomian(?) segment with a density of 2.84 g cm− 3, with its upper boundary ranging from 10 to 18 km located beneath the Veporic unit, or a purely hypothetical eclogite layer with a density of 3.51 g⋅cm− 3 within the mantle. Such an interdisciplinary approach combining geophysical and petrological data is also applicable in other continental tectonic settings. Detection of crustal and mantle sources related to deep-seated deformation zones through specific geophysical patterns could play an important role in global lithosphere research.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10507 - Volcanology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Global and Planetary Change

ISSN

0921-8181

e-ISSN

1872-6364

Svazek periodika

247

Číslo periodika v rámci svazku

April

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

23

Strana od-do

104735

Kód UT WoS článku

001428083900001

EID výsledku v databázi Scopus

2-s2.0-85217415196