| SPELEOTHEMS |
Holmgren et al. 2003 Cold Air Cave Stalagmite 25KYr Stable Isotope Data
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Holmgren, K.;Lee-Thorp, J.A.;Cooper, G.R.J.;Lundblad, K.;Partridge, T.C.;Scott, L.;Sithaldeen, R.;Talma, A.S.;Tyson, P.D.
2003 Persistent millennial-scale climatic variability over the past 25,000 years in Southern Africa. Quaternary Science Reviews
Vol. 22, Issues 21-22, November-December 2003, Pages 2311-2326
| Data Coverage |
North: -24.02 * South: -24.02 |
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West: 29.11 * East: 29.11 |
Start Year: -22428 AD
End Year: 1998 AD
Data: Please Cite Data Contributors!
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Summary: Data from stalagmites in the Makapansgat Valley, South Africa, document
regional climatic change in southern Africa in the Late Pleistocene and
Holocene. A new TIMS U-series dated stalagmite indicates speleothem growth
from 24.4 to 12.7 ka and from 10.2 to 0 ka, interrupted by a 2.5 ka hiatus.
High-resolution oxygen and carbon stable isotope data suggest that
postglacial warming was first initiated ~17 ka, was interrupted by cooling,
probably associated with the Antarctic Cold Reversal, and was followed by
strong warming after 13.5 ka. The Early Holocene experienced warm,
evaporative conditions with fewer C4 grasses. Cooling is evident from
~6 to 2.5 ka, followed by warming between 1.5 and 2.5 ka and briefly at
~AD 1200. Maximum Holocene cooling occurred at AD 1700. The new stalagmite
largely confirms results from shorter Holocene stalagmites reported earlier.
The strongest variability superimposed on more general trends has a
quasi-periodicity between 2.5 and 4.0 ka. Also present are weaker ~1.0 ka
and ~100-year oscillations, the latter probably solar induced. Given
similarities to the Antarctic records, the proximate driving force
producing millennial- and centennial-scale changes in the Makapansgat
record is postulated to be atmospheric circulation changes associated with
change in the Southern Hemisphere circumpolar westerly wind vortex.
More Info on Speleothems |
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Complete XML Record: noaa-cave-5432
(Last Revised: 2007-10-18 )
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| http://www.ncdc.noaa.gov/paleo/ |
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