| SPELEOTHEMS |
Denniston et al. 1999 north-central USA Speleothem Stable Isotope Data
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Denniston, R.F.;González, L.A.;Baker, R.G.;Asmerom, Y.;Reagan, M.K.;Edwards, R.L.;Alexander, E.C. 1999 Speleothem evidence
for Holocene fluctuations of the prairie-forest ecotone, north-central USA. Holocene Vol. 9, no. 6, p. 671-676.
| Data Coverage |
North: 44.83 * South: 43.62 |
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West: -92.41 * East: -92.25 |
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Altitude: 332 m |
Start Year: -6567 AD
End Year: 1950 AD
Data: Please Cite Data Contributors!
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Summary: Carbon and oxygen isotopic trends from seven Midwestern speleothems record
significant offsets in the timing of middle-Holocene vegetation change.
Interactions of dry Pacific and moist Gulf of Mexico air masses maintained
a sharp moisture gradient across Iowa, Minnesota, and Wisconsin such that
the arrival of prairie was offset by 2000 years between caves and pollen
sites located only 50 km apart. Oxygen isotopes shift concomitantly with
carbon in most cases, although these changes are believed to represent
increased evaporative enrichment of 18O prior to infiltration during the
prairie period.
More Info on Speleothems |
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Complete XML Record: noaa-cave-5428
(Last Revised: 2007-10-18 )
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DOC/NOAA/NESDIS/NCDC (National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce )
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| http://www.ncdc.noaa.gov/paleo/ |
| E-mail: bruce.a.bauer@noaa.gov |
| E-mail: paleo@noaa.gov |
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