Sharpe Ashley E, Kamenov George D, Gilli Adrian, Hodell David A, Emery Kitty F, Brenner Mark, Krigbaum John
Department of Anthropology, University of Florida, Gainesville, Florida, United States of America.
Environmental Archaeology Program, Florida Museum of Natural History, University of Florida, Gainesville, Florida, United States of America.
PLoS One. 2016 Nov 2;11(11):e0164871. doi: 10.1371/journal.pone.0164871. eCollection 2016.
We examined the potential use of lead (Pb) isotopes to source archaeological materials from the Maya region of Mesoamerica. The main objectives were to determine if: 1) geologic terrains throughout the Maya area exhibit distinct lead isotope ratios (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb), and 2) a combination of lead and strontium ratios can enhance sourcing procedures in the Mesoamerica region. We analyzed 60 rock samples 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. Although there is some overlap within certain sub-regions, particularly the geologically diverse Metamorphic Province, lead isotopes can be used to distinguish between the Northern Lowlands, the Southern Lowlands, and the Volcanic Highlands. The distinct lead isotope ratios in the sub-regions are related to the geology of the Maya area, exhibiting a general trend in the lowlands of geologically younger rocks in the north to older rocks in the south, and Cenozoic volcanic rocks in the southern highlands. Combined with other sourcing techniques such as strontium (87Sr/86Sr) and oxygen (δ18O), a regional baseline for lead isotope ratios can contribute to the development of lead isoscapes in the Maya area, and may help to distinguish among geographic sub-regions at a finer scale than has been previously possible. These isotope baselines will provide archaeologists with an additional tool to track the origin and movement of ancient humans and artifacts across this important region.
我们研究了铅（Pb）同位素在确定中美洲玛雅地区考古材料来源方面的潜在用途。主要目标是确定：1）玛雅地区的地质地形是否呈现出不同的铅同位素比率（206Pb/204Pb、207Pb/204Pb和208Pb/204Pb），以及2）铅和锶比率的组合是否能够改进中美洲地区的材料来源确定方法。我们分析了玛雅地区60个岩石样本的铅同位素比率，并对包括墨西哥尤卡坦半岛北部低地、危地马拉和伯利兹的南部低地、火山高地、伯利兹玛雅山脉以及变质省/莫塔瓜河谷在内的玛雅地区的一个具有代表性的样本子集进行了铅、铀和钍浓度分析。尽管在某些子区域存在一些重叠，特别是地质情况多样的变质省，但铅同位素可用于区分北部低地、南部低地和火山高地。子区域中不同的铅同位素比率与玛雅地区的地质情况相关，呈现出北部低地地质年代较年轻岩石到南部较老岩石以及南部高地新生代火山岩的总体趋势。结合锶（87Sr/86Sr）和氧（δ18O）等其他材料来源确定技术，铅同位素比率的区域基线有助于在玛雅地区建立铅同位素等值线图，并且可能有助于在比以往更精细的尺度上区分地理子区域。这些同位素基线将为考古学家提供一个额外的工具，以追踪古代人类和文物在这个重要地区的起源和移动情况。
