Sulphate concentration in cave dripwater and speleothems: long-term trends and overview of its significance as proxy for environmental processes and climate changes

Abstract

18 19Sulphate concentration in speleothems identifies major volcanic eruptions, provide useful information 20 on soil and aquifer dynamics and, similarity to the 14 C bomb peak, its Anthropocene peak can be used 21 to date recent cave formations. However, the transmission of S from the atmosphere to cave dripwater 22 and its incorporation in speleothems is subjected to biogeochemical cycling and accurate studies of 23

Roles of forest bioproductivity, transpiration and fire in a nine-year record of cave dripwater chemistry from southwest Australia

“…The approximate decline in dripwater SO 4 concentrations over the study period is 1.4 mg/l, calculated using the averages of the first and final six months of monitoring. Applying the partition coefficient for S/Ca from dripwater to speleothem used by Borsato et al (2015), yielded an estimated decline in speleothem calcite equivalent to 47 ppm, well above the analytical precision of several ppm for SIMS (e.g. Wynn et al, 2010).…”

“…Progress in quantifying solute storage effects has been made at the Ernesto site where the late 20 th century rise in sulphur pollution is lagged and attenuated in dripwater and speleothem records by around 20 years, due to storage in soil and vegetation (Wynn et al, 2013;Borsato et al, 2015). This work was combined with studies of S distribution in wood (Fairchild et al, 2009;Wynn et al, 2014b) to study environmental S loading using trees and speleothems in parallel.…”

Global Boundary Stratotype Section and Point (GSSP) for the Anthropocene Series: Where and how to look for potential candidates

“…127 (Fohlmeister et al 2011), but which is now declining (Borsato et al 2015). Trace element concentrations increased greatly during the early-20 th century, a time of deforestation in the area (Borsato et al 2007…”

Comparison of δ18O analyses on individual planktic foraminifer (Orbulina universa) shells by SIMS and gas-source mass spectrometry

“…In order to evaluate whether CAS contributes to the observed Δ 18 O SIMS-GSMS , we reference analysis of a calcite speleothem, where CAS concentrations are known to track atmospheric SO 2 sourced by volcanogenic and anthropogenic emissions (e.g. Frisia et al, 2008;Wynn et al, 2010;Borsato et al, 2015). Consequently, CAS concentrations in speleothem calcite have increased by a factor of 10 (from < 10 ppm to~100 ppm) during the past~150 years due to fossil fuel emissions (Frisia et al, 2008;Wynn et al, 2010;Borsato et al, 2015).…”

“…Frisia et al, 2008;Wynn et al, 2010;Borsato et al, 2015). Consequently, CAS concentrations in speleothem calcite have increased by a factor of 10 (from < 10 ppm to~100 ppm) during the past~150 years due to fossil fuel emissions (Frisia et al, 2008;Wynn et al, 2010;Borsato et al, 2015). Yet, Δ 18 O SIMS-GSMS values measured in a speleothem that grew continuously from pre-industrial to modern are temporally invariant within SIMS analytical precision ( ± 0.5‰, 2SD; Orland, 2012…”