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| Titel |
Two distinct decadal and centennial cyclicities forced marine upwelling intensity and precipitation during the late Early Miocene in central Europe |
| VerfasserIn |
G. Auer, W. E. Piller  , M. Harzhauser |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 11, no. 2 ; Nr. 11, no. 2 (2015-02-19), S.283-303 |
| Datensatznummer |
250117169
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| Publikation (Nr.) |
 copernicus.org/cp-11-283-2015.pdf |
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| Schlagwörter |
Sedimentologie, Zyklische Sedimentation, Sedimentationsrate, Kalkiges Nannoplankton, Geochemie, Stratigraphie, Tongrube, Miozän, Neogen, Geochronologie, Nordalpines Vorlandbecken, Paläoenvironment, Laa-Formation, Molassezone |
| Geograf. Schlagwort |
Europa, Österreich, Niederösterreich, Mistelbach (Bezirk), Laa an der Thaya, Weinviertel |
| Blattnummer |
24 [Mistelbach] |
| Blattnummer (UTM) |
5308 [Laa an der Thaya] |
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| Zusammenfassung |
Within a 5.5 m thick succession of Upper Burdigalian (Karpatian) sediments
in the North Alpine Foreland Basin (NAFB; Austria), dated to CNP-zone NN4, a
high-resolution section was logged continuously. One hundred samples were
taken with a resolution of ~10 mm (approximating ~17 years)
per layer and analyzed using an integrated multi-proxy approach.
Earlier analyses of geochemistry and calcareous nannoplankton assemblages
hint at small-scale, short-term variations in paleoenvironmental conditions,
such as water-column stratification, primary productivity, organic matter
flux, bottom-water oxygenation, freshwater influx, and changes in relative
sea level. The results indicate a highly dynamic shallow marine setting that
was subject to high-frequency environmental changes on a decadal to
centennial scale.
Time-series analyses on nine different proxy data sets using REDFIT analysis
and wavelet spectra were applied to resolve a possible cyclic nature of
these variations. Analyses revealed that different proxies for
precipitation, upwelling intensity, and overall productivity were likely
controlled by different cyclicities.
A best-fit adjustment of the likely sedimentation rates within the
high-resolution section resulted in periodicities fitting well with the Lower
(~65 years) and Upper (~113 years) Gleissberg cycle as well
as the Suess/de Vries cycle (~211 years). The section covers a time
span of ~1190 years based on the correlation with solar cycles, which
resulted in an estimated sedimentation rate of 575 mm kyr−1.
For the first time, short-term climate variability on a decadal to
centennial scale is resolved in Lower Miocene shallow marine laminated
sediments in a land-based section. The results hint at a close relationship
between climate variability and solar forcing during the Late Burdigalian.
Moreover, accepting that these cyclicities are indeed of solar origin, this
would indicate that precipitation was driven by the two Gleissberg cycles,
while upwelling was driven by the Suess cycle. Furthermore, proxies for
primary productivity were influenced by both cycles, although the Suess
cycle exerts dominant control, reflecting a stronger influence of upwelling
on primary productivity. |
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