Sharpe et al. 2016.xlsx

Original data for the publication "Lead (Pb) Isotope Baselines for Studies of Ancient Human Migration and Trade in the Maya Region" (PLOS ONE, 2016). Data include results of 60 rock samples analyzed for lead isotope ratios and a representative subset of samples for lead, uranium, and thorium concentrations across the Maya region, including the Northern Lowlands of the Mexican Yucatan Peninsula, the Southern Lowlands of Guatemala and Belize, the Volcanic Highlands, the Belizean Maya Mountains, and the Metamorphic Province/Motagua Valley. Tab labels correspond to the table numbers in the text. Tables 1-4 are identical to those in the text, except that the lead and strontium isotope values include all digits after the decimal. Research methodology and techniques are detailed in the publication text. <br>Table 1: Lead and strontium results from the Mesoamerican samples used in this study. 87Sr/86Sr isotope ratios, with the exception of the samples from Ceibal, were previously reported in Gilli A, Hodell DA, Kamenov GD, Brenner M. Geological and archaeological implications of strontium isotope analysis of exposed bedrock in the Chicxulub crater basin, northwestern Yucatán, Mexico. Geol. 2009; 37: 723-726 and Hodell DA., Quinn RL, Brenner M, Kamenov G. Spatial variation of strontium isotopes (87Sr/86Sr) in the Maya region: A tool for tracking ancient human migration. J Archaeol Sci. 2004; 31: 585–601. Limestone ages obtained using the strontium data with the method described by McArthur JM, Howarth RJ, Bailey TR. LOWESS Version 3. Best-fit line to the marine Sr-isotope curve for 0 to 509 Ma and accompanying look-up table for deriving numerical age. Geol. 2001; 109: 155-169. The abbreviation est. denotes estimates GPS coordinates.<br>Table 2: Lead values from modern botanical and weak-acid soil leachate samples recovered from Yucatan, Mexico. <br>Table 3: Comparison of lead ratios obtained from limestone leachates with residues. The leachate represents the limestone fraction dissolved in 1N HCl. The residue was digested with concentrated HNO3 and HF. The abbreviation est. denotes estimated GPS coordinates.<br>Table 4: Lead, thorium, and uranium concentrations (ppm) in selected samples from the study area. The abbreviation est. denotes estimated GPS coordinates.<br>