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>本数据集为发表于《PLOS ONE》2016年的论文《玛雅地区古代人类迁徙与贸易研究的铅（Pb）同位素基线》的原始数据。数据包含60件岩石样品的铅同位素比值分析结果，以及玛雅地区（涵盖墨西哥尤卡坦半岛北部低地、危地马拉与伯利兹南部低地、火山高地、伯利兹玛雅山脉以及变质岩省/莫塔瓜谷）内部分样品的铅、铀、钍浓度代表性子集。表格标签与论文中的表号一一对应。表1至表4与论文原文一致，仅铅与锶同位素数值保留了小数点后全部有效位数。研究方法与技术细节详见论文正文。 表1：本研究使用的中美洲样品的铅与锶分析结果。除来自塞瓦尔（Ceibal）的样品外，其余样品的87Sr/86Sr同位素比值此前已发表于以下文献：Gilli A, Hodell DA, Kamenov GD, Brenner M. 墨西哥尤卡坦西北部奇克苏鲁布陨石坑盆地裸露基岩的锶同位素分析及其地质与考古学意义. 《地质学》, 2009, 37: 723-726；以及Hodell DA, Quinn RL, Brenner M, Kamenov G. 玛雅地区锶同位素（87Sr/86Sr）的空间变异：追踪古代人类迁徙的工具. 《考古科学杂志》, 2004, 31: 585–601。利用锶数据与McArthur JM、Howarth RJ、Bailey TR提出的方法可获得石灰岩年代，该方法详见：LOWESS Version 3. 0至509 Ma海洋锶同位素曲线的最佳拟合线及配套数值年龄查询表. 《地质学》, 2001, 109: 155-169。缩写“est.”表示估算的GPS坐标。 表2：从墨西哥尤卡坦地区回收的现代植物样品及弱酸土壤浸出液的铅分析结果。 表3：石灰岩浸出液与残渣的铅比值对比。其中浸出液为经1N HCl溶解的石灰岩组分，残渣经浓HNO3与HF消解。缩写“est.”表示估算的GPS坐标。 表4：研究区域内选定样品的铅、钍、铀浓度（单位：ppm）。缩写“est.”表示估算的GPS坐标。