Lake Punta Laguna Isotopic Data: Readme file
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                   NOAA Paleoclimatology Program
                                 and
               World Data Center A- Paleoclimatology
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NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!!

CONTRIBUTOR: J.H. Curtis, D.A. Hodell and M. Brenner, University of Florida
IGBP PAGES/WDCA Data Contribution Series #:  96-021
NAME OF DATA SET: Lake Punta Laguna ostracod and gastropod stable isotopic data
LAST UPDATE: 9/96 (Original receipt date by NOAA/ WDC-A Paleo) 
GEOGRAPHIC REGION: Lake Punta Laguna, Yucatan, Mexico, 20.63°N, 87.5°W
PERIOD OF RECORD: 1600 B.C.-Present
LIST OF FILES: PuntaLaguna.readme, PuntaLaguna.txt (tab-delimited ASCII data file).

DESCRIPTION:
Stable isotopic data (d18O and d13C) with radiocarbon ages, from ostracod 
and gastropod samples taken in Lake Punta Laguna, Yucatan, Mexico.  These 
data were used to reconstruct precipitation/evaporation ratios as a 
paleo-drought indicator, and are correlated to the cultural evolution of 
the Maya.  

The data in PuntaLaguna.csv and PuntaLaguna.txt are unsmoothed.  Data was 
smoothed in Curtis et al 1996.  Water depth at coring site 6.3m.
Species sampled are Cytheridella ilosvayi and Pyrgophorus coronatus.
Precision for d18O is +- 0.09% and for d13C is +- 0.08%.

Radiocarbon dates:
Sample Type      Depth(cm)  Accession#    14C Age(Yr BP)   Calibrated Age(AD/BC)
                                          
Terrestrial Wood      81    OS-6550          610 +-50         1368 AD
Terrestrial Wood     145    OS-10009         965 +-25         1030 AD
Terrestrial Wood     197    OS-10010        1530 +-50          569 AD
Terrestrial Wood     380    OS-6553         2440 +-45          455 BC
Terrestrial Wood     494    OS-6554         2840 +-30          976 BC

ORIGINAL REFERENCE:
Curtis, J.H., D.A. Hodell, and M. Brenner, 1996, Climate Variability on 
the Yucatan Peninsula (Mexico) during the last 3500 years, and implications
for Maya cultural evolution, Quaternary Research 46: 37-47.


SUGGESTED DATA CITATION:
Curtis, J.H., 1996, Stable Isotope Data, Yucatan, Mexico.  IGBP PAGES/World Data Center-A for
Paleoclimatology Data Contribution Series # 96-021.  NOAA/NGDC Paleoclimatology Program,
Boulder CO, USA.