- Title
- Stalagmite carbon isotopes and dead carbon proportion (DCP) in a near-closed-system situation: an interplay between sulphuric and carbonic acid dissolution
- Creator
- Bajo, Petra; Borsato, Andrea; Drysdale, Russell; Hua, Quan; Frisia, Silvia; Zanchetta, Giovanni; Hellstrom, John; Woodhead, Jon
- Relation
- ARC.DP160101058 and ARC FT130100801 http://purl.org/au-research/grants/arc/FT130100801
- Relation
- Geochimica et Cosmochimica Acta Vol. 210, p. 208-227
- Publisher Link
- http://dx.doi.org/10.1016/j.gca.2017.04.038
- Publisher
- Pergamon Press
- Resource Type
- journal article
- Date
- 2017
- Description
- In this study, the ‘dead carbon proportion’ (DCP) calculated from combined U-Th and radiocarbon analyses was used to explore the carbon isotope systematics in Corchia Cave (Italy) speleothems, using the example of stalagmite CC26 which grew during the last ∼12 ka. The DCP values in CC26 are among the highest ever recorded in a stalagmite, spanning the range 44.8–68.8%. A combination of almost closed-system conditions and sulphuric acid dissolution (SAD) are proposed as major drivers in producing such a high DCP with minor contribution from old organic matter from the deep vadose zone. The long-term decrease in both DCP and δ¹³C most likely reflects post-glacial soil recovery above the cave, with a progressive increase of soil CO2 contribution to the total dissolved inorganic carbon (DIC). Pronounced millennial-scale shifts in DCP and relatively small coeval but antipathetic changes in δ¹³C are modulated by the effects of hydrological variability on open and closed-system dissolution, SAD and prior calcite precipitation. Hence, the DCP in Corchia Cave speleothems represents an additional proxy for rainfall amount.
- Subject
- speleothem; dead carbon proportion (DCP); stable isotope ratios of carbon (δ¹³C); sulfuric acid dissolution; Corchia Cave
- Identifier
- http://hdl.handle.net/1959.13/1348299
- Identifier
- uon:30183
- Identifier
- ISSN:0016-7037
- Language
- eng
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