Chemical Mapping to Evaluate Post-Depositional Diagenesis among the Earliest Ceramics in the Teotihuacan Valley, Mexico
Chemical Mapping to Evaluate Post-Depositional Diagenesis among the Earliest Ceramics in the Teotihuacan Valley, Mexico
复制标题
用于评估墨西哥特奥蒂瓦坎山谷最早陶瓷沉积后成岩作用的化学测绘
作者：
W. Stoner;B. Shaulis
化学和矿物采购技术在考古学中通常用于重建过去陶瓷交换和原材料采购实践的模式，但沉积后成岩作用的影响仍然经常被忽视，尽管一些关键研究警告说，考古沉积物中的陶瓷成分往往与生产时的原始成分有很大差异。目前对成岩作用的研究来自于对墨西哥盆地一些最早的陶瓷（公元前1500-100大卡）的大型化学和岩相分析，当时陶瓷贸易网络的发展有助于在中美洲传播早期风格的大炮。一个重要的网站，Altica，一贯提出陶瓷是高钡。我们使用激光烧蚀电感耦合等离子体质谱（LA-ICP-MS）映射的横截面的几个样品从这个网站的想法，沉积后的摄入量的移动的阳离子会出现丰富的陶器的表面和周围的孔隙。相反，从织物中滤出的阳离子将在这些相同的区域中表现出耗尽的浓度。我们发现钡和一组其他元素（例如，铜、锌、铅、锡、砷、钙、锶和钒）由于在土壤中埋藏近3000年而发生化学变化。我们探讨了这些启示的影响，适当采购考古陶瓷发现在阿尔蒂卡网站和考古学家和地球化学家谁雇用陶瓷成分采购其他地方提供额外的指导。
Chemical and mineral sourcing techniques are commonly employed in archaeology to reconstruct patterns of ceramic exchange and raw material procurement practices for the past, but the effects of post-depositional diagenesis are still often ignored despite a number of key studies warning that the composition of ceramics from archaeological deposits often diverges greatly from their original composition at the time of production. This current study on diagenesis derives from a large chemical and petrographic analysis of some of the earliest ceramics (1500–100 cal Before Common Era [BCE]) in the Basin of Mexico at a time when the development of ceramic trade networks helped to spread early stylistic canons across Mesoamerica. One important site, Altica, consistently presents ceramics that are high in barium. We use laser ablation-inductively coupled plazma—mass spectrometry (LA-ICP-MS) to map the cross-sections of several samples from this site with the idea that post-depositional intake of mobile cations would appear as enriched at the surfaces of the pottery and around pores. Conversely, cations that leach out of the fabric would exhibit depleted concentrations in those same areas. We find that barium and a suite of other elements (e.g., copper, zinc, lead, tin, arsenic, calcium, strontium, and vanadium) have been chemically altered due to nearly 3000 years of burial in the soil. We explore the implications of those revelations for properly sourcing archaeological ceramics found at the Altica site and provide additional guidance for archaeologists and geochemists who employ ceramic compositional sourcing elsewhere.