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| Titel |
Spatially and temporally varying Quaternary uplift rates of the Gerecse Hills, Northern Pannonian Basin, using dated geomorphological horizons in the Danube valley |
| VerfasserIn |
Zsófia Ruszkiczay-Rüdiger, László Fodor, Gábor Csillag, Régis Braucher, Sandor Kele, Ágnes Novothny, Edit Thamó-Bozsó, Attila Virág, Gábor Molnár, Balázs Madarász, Aster Team |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250126704
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| Publikation (Nr.) |
 EGU/EGU2016-6463.pdf |
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| Zusammenfassung |
| The assessment of Quaternary vertical deformation rates of uplifted, low altitude hilly regions
is based mainly on the dating of paleo-surfaces that can be related to reference levels through
several stages of landscape evolution. Regarding the Gerecse Hills (NE part of the
Transdanubian Range, Hungary), situated to the south of the incised Danube River
the all-time base-level of the river provides a suitable reference level, because the
intracontinental setting of the study area makes it insensitive of the global sea level
changes.
The terrace sequences of the Hungarian part of the Danube valley preserve a record of
varying tectonic uplift rates along the river course and throughout several climate stages. The
Gerecse Hills consists mainly of Triassic carbonatic rocks and a thin Paleogene and Neogene
siliciclastic cover. The Danube is escorted by a set of Quaternary river terraces and higher
planation surfaces, which may be of Pliocene age. The terraces are covered by alluvial
sediments frequently capped by travertine and/or loess. To establish the chronology of these
terraces, we rely on U-series data of travertines and on new in situ produced cosmogenic
nuclides data combined with luminescence (OSL and postIR-IRSL) ages from the lower
terraces.
In situ produced cosmogenic 10Be concentrations were measured in samples distributed
along vertical depth profiles to enable the determination of both the exposure duration and the
denudation rate at each studied locality. We used Monte Carlo approach to model the
denudation rate-corrected exposure ages. Burial age determinations were performed using
cosmogenic 26Al/10Be nuclide ratios. Post-IR IRSL measurements were carried out on
K-feldspar and OSL measurements on quartz grains to determine the ages of sediment
deposition.
The highest dated horizon (∼115 m above the river) provided a preliminary burial age of
∼2.7 Ma, which is in accordance with the possible time span of sedimentation deduced
from the occurrence of Mammuthus meridionalis teeth in the sampled sediment, or
slightly older. This leads to an average uplift rate of 0.04 mm/a over the last ∼2.7
Ma. On the other hand, U-series data of travertines over the last ∼450 ka suggests
incision rates of ∼0.15-0.55 mm/a and published terrace chronologies as well as
luminescence and 10Be depth profile data lead to values between 0.1 and 0.2 mm/a
suggesting a possible slight acceleration of uplift towards present. In addition, the
presented data indicate that uplift rates in the Gerecse Hills are higher than those in
the area to the west, pointing to structurally controlled eastward increasing uplift
rates.
Thanks to OTKA PD83610, PD100315, K81530, K106197; NKM-96/2014,
NKM-31/2015; OMAA 90öu17; LP2012-27/2012; "MTA Postdoctoral Research
Programme"; INSU/CNRS, the ANR through the program “EQUIPEX Investissement
d’Avenir”, IRD and CEA. |
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