Archaeobotanical records in an Amazonian shell mound: microalgae (Diatomacea,Bacillariophyta) as indicators of environmental changes

Abstract Records of the conditions during the formation of archaeological sites were obtained from interdisciplinary investigations. In archaeobotany, diatoms are microalgae that can depict these previous conditions; when present in archaeological soils, they indicate the presence of watercourses near the site or may permit inferences about paleoenvironmental conditions. This study is the first to describe the diatom record throughout the entire anthracological column of a shell mound. Samples from the Porto da Mina Shell Mound (Quatipuru, Pará, Brazil) were analyzed along the sedimentary column. The diatoms found in the mound reinforce the notion that groups have been associated with the shell mound at the site for at least 210 years. The ecological inferences indicate that the settlement was in a geographically diverse environment, with fresh, brackish, and marine water entering. The inclusion of diatom analysis in the archaeological context represents an additional technique for environmental reconstruction studies.

本研究通过多学科考察获取了考古遗址形成时期的环境记录。在考古植物学（archaeobotany）领域，硅藻（diatom）是一类可反映过往环境状况的微藻类；当其存在于考古遗址的土壤中时，既可指示遗址附近存在水体，也可用于推断古环境条件。本研究首次对一处贝丘遗址（shell mound）的完整木炭沉积柱中的硅藻记录进行了系统描述。研究团队对采自巴西帕拉州夸蒂普鲁市波尔图达米纳贝丘遗址的沉积物柱样开展了全层分析。遗址贝丘中发现的硅藻进一步佐证了：人类至少在210年前就已在此贝丘遗址活动并与其产生关联。生态推断结果显示，该聚落所处的地理环境具有多样性，存在淡水、半咸水与海水交汇的情况。将硅藻分析方法纳入考古研究范畴，可为环境重建研究提供一种补充性技术手段。