Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Biogeochemical cycling of sulphur in karst and transfer into speleothem archives at Grotta di Ernesto, Italy
AU - Wynn, Peter
AU - Borsato, Andrea
AU - Baker, Andy
AU - Frisia, Silvia
AU - Miorandi, Renza
AU - Fairchild, Ian J.
PY - 2013/7
Y1 - 2013/7
N2 - Trace amounts of sulphur in speleothems suggest that stalagmites may act as archives of sulphur deposition, thereby recording aspects of atmospheric variability in sulphur content. Accurate interpretation of this novel sulphur archive depends upon understanding how biogeochemical cycling in the soil and epikarst above the cave may modify the precursor atmospheric values of sulphur concentration and isotopic composition prior to incorporation into the speleothem record. Dual isotope analysis of δ34S-SO4 and δ18O-SO4 is used to trace biogeochemical transformations of atmospheric sulphur through the cave system at Grotta di Ernesto in the Italian Alps and builds towards a framework for interpretation of speleothem sulphur archives which depends on overlying ecosystem dynamics and karst hydrological properties. A three component model of atmospheric signal modification is proposed to be driven by 1. vegetation and soil cycling, 2. the degree of groundwater mixing in the karst aquifer; and 3. redox status. The relative influence of each process is specific to individual drip flow sites and associated stalagmites, rendering each suphur archive a unique signal of environmental conditions. Under conditions found in the soil and epikarst above Grotta di Ernesto, the dual isotope signatures of sulphate sulphur and oxygen incorporated into speleothem carbonate, closely reflect past conditions of industrial sulphur loading to the atmosphere and the extent of signal modification through biogeochemical cycling and aquifer mixing.
AB - Trace amounts of sulphur in speleothems suggest that stalagmites may act as archives of sulphur deposition, thereby recording aspects of atmospheric variability in sulphur content. Accurate interpretation of this novel sulphur archive depends upon understanding how biogeochemical cycling in the soil and epikarst above the cave may modify the precursor atmospheric values of sulphur concentration and isotopic composition prior to incorporation into the speleothem record. Dual isotope analysis of δ34S-SO4 and δ18O-SO4 is used to trace biogeochemical transformations of atmospheric sulphur through the cave system at Grotta di Ernesto in the Italian Alps and builds towards a framework for interpretation of speleothem sulphur archives which depends on overlying ecosystem dynamics and karst hydrological properties. A three component model of atmospheric signal modification is proposed to be driven by 1. vegetation and soil cycling, 2. the degree of groundwater mixing in the karst aquifer; and 3. redox status. The relative influence of each process is specific to individual drip flow sites and associated stalagmites, rendering each suphur archive a unique signal of environmental conditions. Under conditions found in the soil and epikarst above Grotta di Ernesto, the dual isotope signatures of sulphate sulphur and oxygen incorporated into speleothem carbonate, closely reflect past conditions of industrial sulphur loading to the atmosphere and the extent of signal modification through biogeochemical cycling and aquifer mixing.
KW - Sulphur
KW - Isotopes
KW - Biogeochemistry
KW - Speleothem
KW - Karst
U2 - 10.1007/s10533-012-9807-z
DO - 10.1007/s10533-012-9807-z
M3 - Journal article
VL - 114
SP - 255
EP - 267
JO - Biogeochemistry
JF - Biogeochemistry
SN - 0168-2563
IS - 1-3
ER -