Between Westerlies and the Intertropical Convergence Zone: a high-resolution paleoclimate and paleoenvironment study of Holocene sediments of the Layla lakes, Saudi Arabia

阿拉伯半岛在全新世经历了强烈的干旱化，形成了今天的炎热干旱气候。因此，拥有当地地表水的大草原景观消失了，这为人类提供了非洲和新月沃地之间的联系。这一转变只在边缘环境中被记录下来，关于时间和气候框架的公开问题仍然存在。基本的假设是，减少日照阻止热带辐合带在夏季进一步渗透到阿拉伯半岛中部。由于缺乏气候档案，这还没有被限制在阿拉伯半岛中部，冬季西风降水的作用仍然不清楚。直到20世纪90年代，地下水喂养的湖泊存在于天坑约。在利雅得以南300公里的莱拉镇附近。密集的地下水抽取导致湖泊水位下降，并暴露了一个独特的层状湖泊气候档案中，晚全新世在阿拉伯半岛的中心，这样的档案丢失。我们提出了一个多代理的方法，结合分析沉积相，矿物学，地球化学，孢粉学，硅藻，介形类，稳定同位素和建立一个强大的年表检索环境信息。我们期待着新的基本见解阿拉伯半岛的干旱化在全新世中后期和大气环流动力学之间的过渡西风带和热带辐合带，一个地区的古气候信息仍然缺失。

The Arabian Peninsula underwent strong aridification during the Holocene towards the present-day hot arid climate. Consequently, the savannah-like landscape with local surface water disappeared that had provided humans with a connection between Africa and the Fertile Crescent. This transition is documented only from marginal settings, and open questions about the timing and the climatic framework still exist. The fundamental hypothesis is that decreasing insolation prevented the Intertropical Convergence Zone to penetrate further into central Arabia during summer. Because of the lack of climate archives this has not yet been constrained for central Arabia, and the role of Westerly precipitation during winter remains unclear. Until the 1990s, groundwater-fed lakes existed in sinkholes approx. 300 km south of Riyadh near the town of Layla. Intensive groundwater abstraction caused lake levels to sink and exposed a unique laminated lacustrine climate archive for the middle and late Holocene in the centre of the Arabian Peninsula where such archives are missing. We propose a multi-proxy approach that combines analyses of sediment facies, mineralogy, geochemistry, palynology, diatoms, ostracods, and stable isotopes and to establish a robust chronology to retrieve environmental information. We expect fundamental new insights into the aridification of the Arabian Peninsula during the middle and late Holocene and into atmospheric circulation dynamics at the transition between Westerlies and the Intertropical Convergence Zone, an area where paleoclimate information is still missing.