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| Titel |
SING (salt induced noble gas diffusion) in Stassfurt, Germany |
| VerfasserIn |
A. Suckow, J. Sültenfuss, H. Holländer, S. Stadler |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250060714
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| Zusammenfassung |
| Subrosion is a common problem in areas of former salt mining activities, equally in the
former potash mining town of Stassfurt, Germany. To assess the stability of such a system, it
is necessary to identify whether salt dissolution processes are still proceeding and if and how
the surrounding groundwater interacts with the salt structure. Aquifers in Stassfurt were
investigated for hydrodynamics and groundwater interaction with the underlying Zechstein
strata using chemical and isotopic fingerprints (Stadler et al., 2012) to identify potential
implications for land subsidence. Measured noble gas values (He, Ne, 3He/4He) showed
strong variations and exceptionally high excess air values: i) The He content in the sampled
waters does not seem to further increase below a depth of about 100 m b.g.l. ii) Ne solubility
equilibrium at the site’s infiltrations conditions (9.9° C and 70 m altitude) corresponds
to a Ne concentration of 2-
10-7 cm3 STP/g, and Ne concentrations found range
from half this value up to 2.5-fold this value which is a larger scatter than generally
observed for excess air (Heaton & Vogel, 1981; Aeschbach-Hertig et al., 2001). These
patterns are unusual and may be interpreted in terms of flow paths, velocities and
geochemical evolution. In our contribution we discuss the role of salt dissolution
and diffusive processes in the aquifer. We can show that the noble gas data can be
qualitatively explained by the impact of the high subsurface increase in salinity which
induces noble gas diffusion controlled by solubility gradients (Suckow & Sonntag
1993).
References:
Aeschbach-Hertig, W., Beyerle, U., Holocher, J., Peeters, F., Kipfer, R., 2001. Excess air
in groundwater as a potential indicator of past environmental changes. In: International
Conference on the study of environmental change Using Isotope Techniques. Vienna,
IAEA-CN-80/29: 34-36.
Heaton, T.H.E., Vogel, J., 1981. “Excess Air“ in Groundwater. Journal of Hydrology 50:
201-216
Stadler, S., Sültenfuß, J, Holländer, H.M., Bohn, A., Jahnke. C., Suckow, A., Isotopic and
geochemical indicators for groundwater flow and multi-component mixing near disturbed
salt anticlines, Chemical Geology 294–295, pp. 226–242, ISSN 0009-2541, doi:
10.1016/j.chemgeo.2011.12.006
Suckow, A., Sonntag, C., 1993. The influence of Salt on the Noble Gas Thermometer.
Isotope Techniques in the Study of Past and Current Environmental Changes in the
Hydrosphere and the Atmosphere IAEA-SM-329/64: 307-318. |
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