Extended-Range Luminescence Dating of Central and Eastern Amazonia Sandy Terrains
Extended-Range Luminescence Dating of Central and Eastern Amazonia Sandy Terrains
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DOI：
10.3389/feart.2022.888443
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发表时间：
2022-07
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通讯作者：
Fernanda Costa G. Rodrigues;N. Porat;T. Mineli;I. del Río;P. Niyonzima;L. Nogueira;F. Pupim;C. Silva;P. Baker;S. Fritz;I. Wahnfried;Gustavo Kiefer;A. Sawakuchi
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作者：
Fernanda Costa G. Rodrigues;N. Porat;T. Mineli;I. del Río;P. Niyonzima;L. Nogueira;F. Pupim;C. Silva;P. Baker;S. Fritz;I. Wahnfried;Gustavo Kiefer;A. Sawakuchi
亚马逊生物群系拥有高地封闭和开放的植被生态系统，其中当前的生物地理格局与自然景观的演变有关。因此，了解支持不同生态系统的基质的起源和时间对于更好地理解亚马逊生物地理学是必不可少的。在这里，我们使用石英光激发发光（OSL）和热传递光激发发光（TT-OSL）来测定亚马逊中部和东部封闭和开放植被环境下的砂质基质的年龄，这些样品来自露头和钻孔岩芯样品（Autazes岩芯：PBAT-15-43）。这些砂质底物的年龄从1 ka到近2 Ma不等，主要被解释为河流阶地的沉积年龄。此外，还讨论了导致基底形成的潜在地貌过程的年龄，例如土壤混合和来自母基岩的石英的表观年龄。OSL和TT-OSL技术之间的耦合使我们能够确定整个第四纪的沉积沉积物，这为亚马逊河流域的历史提供了一个新的时间窗口。
The Amazonia biome hosts upland closed and open vegetation ecosystems, in which the current biogeographical patterns relate to the evolution of the physical landscape. Therefore, understanding the origin and timing of the substrates supporting different ecosystems is indispensable for better comprehension of Amazonian biogeography. Here we used quartz optically stimulated luminescence (OSL) and thermally transferred optically stimulated luminescence (TT-OSL) for dating sandy substrates of closed and open vegetation environments in Central and Eastern Amazonia, from both outcrop and drill core samples (Autazes core: PBAT-15-43). These sandy substrates present ages ranging from 1 ka up to almost 2 Ma, that were primarily interpreted as depositional ages of fluvial terraces. Moreover, ages are discussed in terms of potential geomorphic processes leading to the formation of substrates, such as soil mixing and apparent age of quartz from the parent bedrock. The coupling between OSL and TT-OSL techniques allow us to date sedimentary deposits covering the whole Quaternary, which implies a new time window for the Amazonia history.