Provenance, modification and use of manganese-rich rocks at Le Moustier (Dordogne, France)

The use of colouring materials by Neanderthals has attracted a great deal of attention in recent years. Here we present a taphonomic, technological, chemical-mineralogical and functional analysis of fifty-four manganese rich lumps recovered during past and on-going excavations at the lower rockshelter of Le Moustier (Dordogne, France). We compare compositional data for archaeological specimens with the same information for twelve potential geological sources. Morphometric analysis shows that material from Peyrony’s excavations before the First World War provides a highly biased picture of the importance of these materials for Mousterian groups. These early excavations almost exclusively recovered large modified pieces, while Mn-rich lumps from the on-going excavations predominantly consist of small pieces, only half of which bear traces of modification. We estimate that at least 168 pieces were not recovered during early work at the site. Neanderthals developed a dedicated technology for processing Mn-rich fragments, which involved a variety of tools and motions. Processing techniques were adapted to the size and density of the raw material, and evidence exists for the successive or alternating use of different techniques. Morphological, textural and chemical differences between geological and archaeological samples suggest that Neanderthals did not collect Mn-rich lumps at the outcrops we sampled. The association and variability in Mn, Ni, As, Ba content, compared to that observed at the sampled outcrops, suggests that either the Le Moustier lumps come from a unique source with a broad variation in composition, associating Mn, Ni, As, Ba, or that they were collected at different sources, characterized either by Mn-Ni-As or Mn-Ba. In the latter case, changes in raw material composition across the stratigraphy support the idea that Neanderthal populations bearing different stone tool technologies collected Mn fragments from different outcrops. Our results favour a use of these materials for multiple utilitarian and symbolic purposes.近年来，尼安德特人使用着色材料的相关研究已引发学界广泛关注。本文针对法国多尔多涅省勒穆斯特耶（Le Moustier）下层岩棚遗址既往发掘与当前正在进行的发掘工作中出土的54块富锰团块，开展了埋藏学、技术学、化学矿物学与功能学分析，并将考古标本的成分数据与12处潜在地质矿源的对应信息进行了比对。 形态计量分析显示，第一次世界大战前佩罗尼（Peyrony）的发掘所获材料，对莫斯特文化群体使用这类材料的重要性呈现出严重偏差的认知。早期发掘几乎仅回收了大型加工过的标本，而当前发掘所获的富锰团块则以小型标本为主，其中仅半数带有加工痕迹。我们估算，该遗址早期发掘工作漏采了至少168块标本。 尼安德特人开发了专门的加工技术以处理富锰碎屑，该技术涉及多种工具与操作动作。加工工艺会根据原材料的尺寸与密度进行调整，且存在先后使用或交替使用不同技术的证据。 地质样品与考古样品在形态、质地与化学组成上的差异表明，尼安德特人并未在我们采样的露头处采集富锰团块。相较于采样露头处的观测结果，勒穆斯特耶标本中锰（Mn）、镍（Ni）、砷（As）、钡（Ba）的含量关联与变异特征提示两种可能性：其一，勒穆斯特耶的富锰团块源自单一成分波动范围较广的矿源，且该矿源同时伴生Mn、Ni、As、Ba；其二，这些标本采自不同矿源，分别以Mn-Ni-As组合或Mn-Ba组合为特征。若为后者，地层剖面中原材料成分的变化则支持这一观点：拥有不同石器技术的尼安德特人群体，会从不同露头处采集富锰碎屑。 我们的研究结果表明，这类材料被尼安德特人用于多种实用与象征性功能用途。