Abstract

It has often been thought that shallow open sites (<50 cm of artefact-bearing deposit) in the undulating landscape of the Cumberland Plain would not retain any chronologically meaningful vertical distributions. The prevailing geomorphic model has proposed that artefacts discarded by people at different times would have been buried and mixed together by bioturbation. To address this model, this paper analyses the vertical distributions of artefacts at 21 open sites and finds that 13 of those sites show vertical variation in the proportions of indurated mudstone/silicified tuff (IMST), silcrete and/or quartz artefacts. The trends shown by the distributions are broadly consistent with a known regional change in raw material use and indicate the survival of some chronologically meaningful artefact variation with depth of the deposit. In addition, sites with increased proportions of older IMST artefacts in deeper deposits tend to be associated with larger streams and tend to occur at low elevations. This suggests that the survival of older artefacts could be related in part to long-term geomorphic processes visible at the landscape scale. The results indicate that sites may have differing histories of visitation, artefact discard, geomorphic processes and survival of evidence, and that careful, stratigraphic excavation is warranted.

摘要

人们通常认为坎伯兰平原起伏景观中的浅层开放地点（<50 厘米的人工制品沉积物）不会保留任何按时间顺序排列的垂直分布。流行的地貌模型提出，人们在不同时期丢弃的文物会被生物扰动掩埋并混合在一起。为了解决这个模型，本文分析了 21 个开放地点的人工制品的垂直分布，发现其中 13 个站点显示出硬质泥岩/硅化凝灰岩 (IMST)、硅质混凝土和/或石英人工制品比例的垂直变化。分布所显示的趋势与已知的原材料使用区域变化大体一致，并表明一些具有年代意义的人工制品随矿床深度变化的存留。此外，在较深的沉积物中，较旧的 IMST 人工制品比例增加的地点往往与较大的河流有关，并且往往发生在低海拔地区。这表明，较旧的人工制品的存留可能部分与在景观尺度上可见的长期地貌过程有关。结果表明，这些地点可能具有不同的访问历史、文物丢弃历史、地貌过程和证据存留历史，因此有必要进行仔细的地层挖掘。