Jennings Cave, Florida, USA d13C cave sediment Data from -984 to 2007 CE Polk, J.S.; van Beynen, P.E.; Asmerom, Y.; Polyak, V.J. Polk, J.S. van Beynen, P.E. Asmerom, Y. Polyak, V.J. earth science/paleoclimate/speleothems (depth,null,null,centimeter,null,speleothems,null,null,N,composite sediment depth) earth science/paleoclimate/speleothems (delta 13C,fulvic acid,null,per mil VPDB,null,speleothems,null,null,N,null) earth science/paleoclimate/speleothems (Jennings Cave, Florida>LATITUDE 29.15827>LONGITUDE -82.3519) 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 δ13C record shows the dominance of C3 vegetation during this period, but with changes in abundance and the shifting presence of C4 plants. The δ13C 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 δ13C and δ18O values of two uranium-series dated speleothems from this part of Florida, with both being proxies for precipitation change. STUDY NOTES: Contributed to NOAA Paleoclimatology as part of Rodysill et al. 2018 synthesis study. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Polk, J.S. Investigator : van Beynen, P.E. Investigator : Asmerom, Y. Investigator : Polyak, V.J. 2018-08-14 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/24979 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/northamerica/usa/florida/polk2013/polk2013-jennings.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/northamerica/usa/florida/polk2013/polk2013-jennings.txt English https://www.ncdc.noaa.gov/paleo/study/24979 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/northamerica/usa/florida/polk2013/polk2013-jennings.txt Polk, J.S., P. van Beynen, Y. Asmerom, and V.J. Polyak2013Reconstructing past climates using carbon isotopes from fulvic acids in cave sedimentsChemical Geology360-3611-910.1016/j.chemgeo.2013.09.022 -82.3519 29.15827 -82.3519 29.15827