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| Titel |
Calcite precipitation on glass substrates and active stalagmites in
Katerloch Cave (Austria): Constraints from environmental monitoring |
| VerfasserIn |
Marlene Sakoparnig, Ronny Boch, Xianfeng Wang, Ke Lin, Christoph Spötl, Albrecht Leis, Anna Gollowitsch, Martin Dietzel |
| 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 |
250136421
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| Publikation (Nr.) |
 EGU/EGU2016-17458.pdf |
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| Schlagwörter |
Höhle, Naturdenkmal (Höhle), Stalagmit, Petrographie, Isotope, Geochemie, Umwelt, Monitoring, Grazer Paläozoikum |
| Geograf. Schlagwort |
Österreich, Steiermark, Weiz (Bezirk), Katerloch (Höhle), Grazer Bergland |
| Blattnummer |
134 [Passail] |
| Blattnummer (UTM) |
4223 [Weiz] |
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| Zusammenfassung |
| Located near Graz at the SE-rim of the Alps Katerloch is well-known for its impressive
dripstone decoration, e.g. several metres tall and relatively fast growing (0.2-0.7 mm/yr on
average) candle-stick-type stalagmites. In the course of an ongoing multi-annual and partially
high-resolution cave monitoring program we study modern (active) sites of carbonate
deposition focusing on the site-specific growth dynamics and connection of modern regional
and cave environmental conditions with petrographic, chemical and stable isotopic
information captured in the speleothems.
Fresh calcite precipitates on artificial (glass) substrates underneath active drip sites were
collected continuously from 2006 to 2014 (eight years!). The samples (up to 7 mm
thick) represent cave sections of different temperature and drip sites of partially
different characteristics (e.g. drip rate). We also recovered short drill cores (up to 3 cm
length, 1 cm diameter) from the top of active stalagmites probably representing the
last decades to centuries of calcite crystallization. Moreover, an actively growing
stalagmite (K10) comprising both modern and past calcite deposition was collected.
238U-234U-230Th dating using MC-ICP-MS of K10 (71 cm long) revealed several
distinct growth intervals (separated by growth interruptions) starting at 129.1 ±1.2
kyr BP (Last Interglacial) up to now, mostly reflecting warm and humid climate
intervals.
High-resolution (100 μm) isotope profiles micromilled from the multi-annual modern
calcite precipitates on artificial substrates revealed low δ13C values of -12.8 to -8.3
‰ (VPDB) and relatively high δ18O of -6.9 to -4.9 ‰Ṫhe δ18O curves from all collection
sites (different growth rate) record a pronounced decrease during their most recent growth
period most likely corresponding to a significant decrease towards lower oxygen isotope
values observed in drip waters collected in the year 2014 compared with samples from 2005
to 2007. Drip water δ2H /δ18O values plot between the Western Mediterranean Meteoric
Water Line and Global MWL indicating a significant contribution of Mediterranean moisture
to regional precipitation. The prominent shifts could also be explained by changes in
seasonality of precipitation and water infiltration. Geochemical and petrographic results from
the modern stalagmite calcite are therefore compared to new and published (Boch et al.,
2011) hydrochemical and cave air data, as well as regional meteorological data. The modern
datasets are further compared to data from Katerloch stalagmites of older time
intervals.
BOCH, R., SPÖTL, C., FRISIA, S. (2011): Sedimentology, 58, 508-531 |
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