Late Pleistocene site formation and paleoclimate at Lapa do Picareiro, Portugal
Late Pleistocene site formation and paleoclimate at Lapa do Picareiro, Portugal
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DOI：
10.1002/gea.21735
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发表时间：
2019-11-01
影响因子：
1.7
通讯作者：
Ellwood, Brooks B.
中科院分区：
文献类型：
--
作者：
Benedetti, Michael M.;Haws, Jonathan A.;Ellwood, Brooks B.
葡萄牙Lapa do Picareiro的洞穴遗址包含一个深(约10米)的沉积序列，代表了中旧石器时代的大部分地区，在壁炉中有丰富的动物骨骼、石质/骨骼/贝壳文物和木炭/灰烬。基于49个放射性碳年龄的沉积模型表明，在9~45ka之间，平均沉积速率为0.1-0.3 mm a(-1)。外推年龄为65~78ka。洞穴沉积物主要是来自顶板剥落的石灰岩Eboulis，以及来自风化土壤渗入基岩节理和缝隙的泥质细粒沉积物。洞穴中的骨骼保存良好，生物扰动、溶解或侵蚀过程的干扰似乎是有限的。大多数沉积学参数随深度的变化是保守的，表明随着时间的推移，沉积物来源稳定。几个参数与放射性碳测年剖面的古气候记录显示出很好的一致性。寒冷干旱的海因里希主岩以粗碎屑层为代表，细粒沉积物和磁化率极小值很少，而温和的格陵兰间主岩对应于泥质层和尖锐的磁化率峰。这项研究是对该遗址正在进行的考古发掘的补充，并确认该序列具有适当的年龄、分辨率和保存，可以提供关于晚更新世文化和气候转变的信息。
The cave site of Lapa do Picareiro, Portugal contains a deep (~10 m) sedimentary sequence representing much of the Middle and Upper Paleolithic, with abundant animal bones, lithic/bone/shell artifacts, and charcoal/ash in hearths. A deposition model based on 49 radiocarbon ages demonstrates average sedimentation rates of 0.1-0.3 mm a(-1) between 9 and 45 ka. Extrapolation suggests an age at the base of the excavation of 65-78 ka. The cave sediments are primarily limestone eboulis derived from roof spalling, and muddy fine sediment derived from weathered soil infiltrating through bedrock joints and crevices. Bone preservation in the cave is good and disturbance by bioturbation, dissolution, or erosional processes appears to be limited. Most sedimentological parameters vary conservatively with depth, indicating stable sediment sources over time. Several parameters show good agreement with paleoclimate records over the radiocarbon-dated section. The cold-arid Heinrich stadials are represented by coarse-clast beds with little fine sediment and magnetic susceptibility minima, and mild Greenland interstadials correspond with muddy beds and sharp peaks in magnetic susceptibility. This study complements ongoing archaeological excavation at the site and confirms that the sequence has the proper age, resolution, and preservation to inform on Late Pleistocene cultural and climatic transitions.