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001-es BibID:	BIBFORM127815
035-os BibID:	(WoS)001354466700001 (Scopus)85208426943
Első szerző:	Püspöki Zoltán (geológus)
Cím:	A quasi-continuous long-term (5 Ma) Mid-European mountain permafrost record based on fluvial magnetic susceptibility and its contribution to the explanation of Plio-Pleistocene glaciations / Püspöki, Zoltán; Markos, Gábor; Fancsik, Tamás; Bereczki, László; Kiss, László Ferenc; Thamó-Bozsó, Edit; Krassay, Zita; Kovács, Péter; McIntosh, Richard W.; Vári, Zoltán; Stercel, Ferenc; Lantos, Zoltán; Maigut, Vera; Sári, Katalin; Rásonyi, Miklós; Gibbard, Philip L.
Dátum:	2024
ISSN:	0300-9483
Megjegyzések:	The low field magnetic susceptibility (?LF) measured in the 1116-m-long Dévaványa core (Pannonian Basin) is a quasi-continuous record of the Plio?Pleistocene Mid-European mountain permafrost development. The continuity of fluvial conditions is confirmed by seismic data, and the detrital origin of magnetite is indicated by frequency-dependent susceptibility measurements, scanning electron microscope, and hysteresis investigations. The ?LF record is correlated to the ?18O curve (LR04) supported by palaeomagnetic data. The colour of samples documents precession and obliquity cycles in local facies variations, but the ?LF indicates the dominance of 100-ka eccentricity cycles in the linked mountainous permafrost events. Comparison with orbital solutions revealed that the long-term development of permafrost occurs as a result of amplitude modulation of the 100-ka eccentricity cycles. Increases in amplitude of the 100-ka cycles inhibits permafrost development due to shortened winters. Thus, if extremes are present, the permafrost regions are limited or disappear, but if the 100-ka eccentricity cycles are attenuated, permanent frost can extend into the temperate zone. This amplitude modulation may also be responsible for the early glaciations during the Pliocene, for the intensification of Northern Hemisphere glaciation, foreshadows cooling in the forthcoming 405-ka term, and allows the change from 41-ka cycles to 100-ka ones in the Mid-Pleistocene Transition to be explained. The 41-ka cycles are the result of obliquity-controlled changes close to the polar cycles, while 100-ka cycles occur when the amplitude attenuation of the 100-ka eccentricity cycles enables extended glaciations that suppress the regular 41-ka cycles. Higher mountains in the catchments enable higher resolution of permafrost records documenting even smaller glaciations. However, the similarities in the overall trends in ?LF records of catchment areas with 1500-m difference in their altitude is a potential counter-argument when considering the role of tectonic elevations in the expansions of mountainous permafrost.
Tárgyszavak:	Természettudományok Földtudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk eccentricity frequency dependence glaciation hysteresis magnetic susceptibility magnetite mountain region permafrost Pleistocene Pliocene scanning electron microscopy seismic data
Megjelenés:	Boreas. - 54 : 1 (2024), p. 156-177. -
További szerzők:	Markos Gábor Fancsik Tamás Bereczki László Kiss László Ferenc Thamó-Bozsó Edit Krassay Zita Kovács Péter McIntosh, Richard William (1978-) (geológus) Vári Zoltán Stercel Ferenc Lantos Zoltán Maigut Vera Sári Katalin Raspagliesi, Francesco Gibbard, Philip L.
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001-es BibID:	BIBFORM113616
035-os BibID:	(Scopus)85159930400 (Wos)000994047500001
Első szerző:	Püspöki Zoltán (geológus)
Cím:	Obliquity-driven mountain permafrost-related fluvial magnetic susceptibility cycles in the Quaternary mid-latitude long-term (2.5 Ma) fluvial Maros Fan in the Pannonian Basin / Püspöki Zoltán, Gibbard, Philip L., Kiss László Ferenc, McIntosh, Richard W., Thamó-Bozsó Edit, Krassay Zita, Szappanos Bálint, Maigut, Vera, Kovács Péter, Karácsony Dominik, Stercel Ferenc, Visnovitz Ferenc, Demény Krisztina, Bereczki László, Szőcs Teodóra, Rotár-Szalkai Ágnes, Fancsik Tamás
Dátum:	2023
ISSN:	0300-9483
Megjegyzések:	Magnetic susceptibility (MS) of the Quaternary long-term mid-latitude Maros fluvial fan (Pannonian Basin) was recorded to understand the stratigraphical features of source-proximal fluvial depositional settings. Three fully cored 500-m-deep boreholes were sampled at 0.5-m intervals; low-field and frequency dependent MS were measured, and complementary hysteresis and SEM-EDAX investigations were performed on selected samples. Logged susceptibility data were also used to log correlations established by a simultaneous comparison of wireline log and laboratory measurements. Time-series analyses of the susceptibility records reveal a similar to 41-ka and similar to 100-ka cyclicity. Towards the source-distal sections the intensity of the similar to 41-ka cycles decreases, while that of the similar to 100-ka cycles remains strong. Stratigraphical and spectral similarities were observed between the Maros fluvial fan and Chinese loess records; however, based on complementary magnetic data, the magnetic phase of the Maros Fan sections is related to the detrital magnetite that originates from the catchment during early postglacial permafrost degradations. The amplification of the similar to 41-ka cycles can be attributed to the very high susceptibility values in source-proximal settings and to the special stratigraphical feature of the distributive fluvial systems. This comprises the increased avulsion frequency on the fluvial fans in 'glacial recession periods', in concert with the 'early postglacial' occurrence of the permafrost-related magnetite originating from the catchment. As a local phenomenon, this is significant since it records the obliquity-driven variations in permafrost development in a catchment. However, fluvial and alluvial fans are widespread depositional landforms within the Eurasian mountain range and were possibly the same during the Quaternary deglaciations. Thus, obliquity-driven magnetic susceptibility variations in source-proximal fan deposits attached or adjacent to regions of loess deposition should also be considered when scanning for potential source material of aeolian deposits.
Tárgyszavak:	Természettudományok Földtudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Boreas. - 52 : 3 (2023), p. 402-426. -
További szerzők:	Gibbard, Philip L. Kiss László Ferenc McIntosh, Richard William (1978-) (geológus) Thamó-Bozsó Edit Krassay Zita Szappanos Bálint Maigut Vera Kovács Péter Karácsony Dominik Stercel Ferenc Visnovitz Ferenc Demény Krisztina Bereczki László Szőcs Teodóra Rotár-Szalkai, Ágnes Fancsik Tamás
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