Environmental history of northwest Australia based on phytolith analysis at Carpenter's Gap 1
Environmental history of northwest Australia based on phytolith analysis at Carpenter's Gap 1
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DOI：
10.1016/s1040-6182(01)00033-7
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发表时间：
2001-09
影响因子：
2.2
通讯作者：
Lynley A. Wallis
中科院分区：
文献类型：
--
作者：
Lynley A. Wallis
检查植硅石组合从考古遗址的木匠的差距1提供了一个迄今未被认可的来源，澳大利亚西北部的热带萨凡纳地区的植被历史。两种主要机制促成了植硅体组合的形成：首先，植物材料中的植硅体引入人类带来的，其次，植物体中所含的动物粪便沉淀的介绍。分离这两种机制的影响，使当地的植被模式，并推断，气候条件，被重建。时期CA。40，000年前的BP可能比今天更潮湿，允许棕榈树向南扩张，超出了它们现在的分布范围。草地组成的变化发生在约。33，000年BP，可能是由于降雨量减少，温度下降和可能的土著人射击活动的组合。棕榈在类似的时间减少，随后完全消失，与Ulmaceae的损失之前，末次盛冰期（LGM）表明，在减少水的可用性的持续趋势。丰富的莎草科，海绵骨针和硅藻在末次盛冰期，当考虑与其他证据，可能代表人类行为的改变，以应对干旱的增加。
Examination of a phytolith assemblage from the archaeological site of Carpenter's Gap 1 provides an hitherto unrecognised source of vegetation history for the tropical savannah region of north western Australia. Two predominant mechanisms contributed to the formation of the phytolith assemblage: firstly, the introduction of phytoliths in plant materials brought in by humans, and, secondly, the introduction of phytoliths contained in faecal pellets deposited by animals. Separating the effects of both mechanisms enables local vegetation patterns, and, by inference, climatic conditions, to be reconstructed. The period ca. 40,000 years BP was probably wetter than today, allowing the southerly expansion of palms beyond their present day distribution. Grassland compositional changes occurred by ca. 33,000 years BP, probably resulting from a combination of lowered rainfall, decreased temperatures and possibly Aboriginal firing activities. A reduction in palm at a similar time, followed by its complete disappearance, in association with the loss of Ulmaceae prior to the Last Glacial Maximum (LGM) indicates a continued trend in decreasing water availability. An abundance of Cyperaceae, sponge spicules and diatoms during the LGM, when considered in conjunction with the other evidence, possibly represents altered human behaviour in response to increased aridity.