Interpreting and modelling late Quaternary dune accumulation in the southern Arabian Peninsula
Interpreting and modelling late Quaternary dune accumulation in the southern Arabian Peninsula
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DOI：
10.1016/j.quascirev.2014.08.002
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发表时间：
2014-10
影响因子：
4
通讯作者：
C. Leighton;R. Bailey;D. G. Thomas
中科院分区：
文献类型：
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作者：
C. Leighton;R. Bailey;D. G. Thomas
在第四纪旱地环境条件重建中的一个基本问题是：沙丘光释光年龄在古环境变化方面意味着什么？本文研究了阿拉伯半岛南部近30 ka以来沙丘年代学记录与外部环境强迫的关系。从该地区的风成记录进行审查，参考其他区域的古环境代理，这些研究结果与模拟评估沙丘响应的风成系统状态的东北鲁卜哈利。该模型复制了一系列功能的区域沙丘年表时，被迫由三个外部参数（沉积物供应，沉积物的可用性和运输能力），包括广泛的区域沙丘堆积在晚更新世-全新世过渡和减少活动在全新世早期潮湿时期。沙丘年表纳入外部强迫参数和本地化的短期因素作为随机过程的影响。厚的沉积单元最有可能代表有利于风成沉积物搬运和沉积的外部强迫条件，但与此同时，这些因素也可能由不同地点沉积物的侵蚀时期来代表。因此，根据个别地层记录的结果，不可能对过去的环境条件作出可靠的解释。需要在多个地点取样，以区分沙丘的积累和保存，由于外部强迫沙丘发展的随机过程。
One of the fundamental questions in the reconstruction of Quaternary dryland environmental conditions is: what do dune OSL ages mean in terms of palaeoenvironmental change? This paper investigates the relationship between dune chronological records and external environmental forcing in the southern Arabian Peninsula during the last 30 ka. Aeolian records from the region are reviewed with reference to other regional palaeoenvironmental proxies, and these findings are related to a modelled assessment of dune response to the aeolian system state of the northeastern Rub' al Khali. The model replicates a range of features of the regional dune chronology when forced by three external parameters (sediment supply, sediment availability, and transport capacity), including extensive regional dune accumulation during the late Pleistocene–Holocene transition and reduced activity during the early Holocene humid period. Dune chronologies incorporate the influence of both external forcing parameters and localised short-term factors included as stochastic processes. Thick sedimentary units most likely represent external forcing conditions conducive to aeolian sediment transport and deposition, but at the same time these factors may be represented by periods of erosion of sediment at different sites. Confident interpretation of past environmental conditions is therefore not possible based on results from individual stratigraphic records. Sampling at multiple locations is needed in order to distinguish dune accumulation and preservation due to external forcing from stochastic processes of dune development.