New U/Th ages for Pleistocene megafauna deposits of southeastern Queensland, Australia

详细信息    查看全文

• 作者：Gilbert J. Price ; Jian-xin Zhao ; Yue-xing Feng ; Scott A. Hocknull
• 关键词：Megafauna ; Extinction ; Pleistocene ; U-series dating ; Australia
• 刊名：Journal of Asian Earth Sciences
• 出版年：2009
• 出版时间：February 2009
• 年：2009
• 卷：34
• 期：2
• 页码：190-197
• 全文大小：442 K

文摘

Arguments over the extinction of Pleistocene megafauna have become particularly polarised in recent years. Causes for the extinctions are widely debated with climate change, human hunting and/or habitat modification, or a combination of those factors, being the dominant hypotheses. However, a lack of a spatially constrained chronology for many megafauna renders most hypotheses difficult to test. Here, we present several new U/Th dates for a series of previously undated, megafauna-bearing localities from southeastern Queensland, Australia. The sites were previously used to argue for or against various megafauna extinction hypotheses, and are the type localities for two now-extinct Pleistocene marsupials (including the giant koala, Phascolarctos stirtoni). The new dating allows the deposits to be placed in a spatially- and temporally constrained context relevant to the understanding of Australian megafaunal extinctions. The results indicate that The Joint (Texas Caves) megafaunal assemblage is middle Pleistocene or older (>292 ky); the Cement Mills (Gore) megafaunal assemblage is late Pleistocene or older (>53 ky); and the Russenden Cave Bone Chamber (Texas Caves) megafaunal assemblage is late Pleistocene (55 ky). Importantly, the new results broadly show that the sites date prior to the hypothesised megafaunal extinction ‘window’ (i.e., 30–50 ky), and therefore, cannot be used to argue exclusively for or against human/climate change extinction models, without first exploring their palaeoecological significance on wider temporal and spatial scales.