Reconstructing past climates using carbon isotopes from fulvic acids in cave sediments
- Permanent Link:
- Reconstructing past climates using carbon isotopes from fulvic acids in cave sediments
- Series Title:
- Chemical Geology
- Polk, Jason S.
van Beynen, Philip
Polyak, Victor J.
- Publication Date:
- Subjects / Keywords:
- Cave Sediments ( local )
Paleoclimate ( local )
Fulvic Acids ( local )
Speleothems ( local )
Precipitation ( local )
Vegetation Change ( local )
- serial ( sobekcm )
- Little is known about the potential of organic substances found within cave sediments to provide useful reconstructions of past climatic changes. Here, we present a study of the carbon isotopes of fulvic acids extracted from sediments from a cave in west-central Florida. Fulvic acids are the most contemporaneous representation of soil humic substances derived from vegetation growing above the cave. Radiocarbon dating of these sediments constrains their depositional period to be late-Holocene. The range of the fulvic acid Î´13C record shows the dominance of C3 vegetation during this period, but with changes in abundance and the shifting presence of C4 plants. The Î´13C values record both the Little Ice Age and Medieval Climate Anomaly which produce drier and wetter conditions for Florida, respectively. Our conclusion that the stable carbon isotopic values of the cave sediment record as a proxy for vegetation change as driven by variability in precipitation is strongly supported by a comparison with the Î´13C and Î´18O values of two uranium-series dated speleothems from this part of Florida, with both being proxies for precipitation change.
- Original Version:
- Chemical Geology, Vol. 360-361 (2013-12-18).
- Source Institution:
- University of South Florida Library
- Holding Location:
- University of South Florida
- Rights Management:
- This object is protected by copyright, and is made available here for research and educational purposes. Permission to reuse, publish, or reproduce the object beyond the bounds of Fair Use or other exemptions to copyright law must be obtained from the copyright holder.
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