ABSTRACT

Intraplate tectonism and continental climate change have important roles in the evolution of the arid Lake Eyre Basin, one of the world’s largest interior basins, and a place with economic, environmental, and cultural significance for many Australians. Just off one of the main rivers of the Basin, Cooper Creek, Lake Yamma Yamma – a 20 km by 40 km ephemeral feature – traps sediment ~750 km upstream and ~90 m higher than the ultimate base level of the Basin – Kati Thanda-Lake Eyre. This paper is the first to report on the sedimentology and geomorphic evolution of this modern ephemeral playa lake. Field-based sedimentology, laboratory-based grain size analysis, satellite image interpretation, inundation frequency maps, hydrological data, and digital elevation data, were used to interpret sedimentary processes and the evolution of the lake. Results suggest Lake Yamma Yamma is a long-lived feature. Evolution is primarily structurally controlled, with the main lake delta migrating north-west over time. Quaternary fluvial, lacustrine and aeolian deposition is likely controlled by intraplate tectonism, and palaeo-shorelines may be remnant features of a prior climate regime. Age dating of this sedimentary archive could provide important information on the history, palaeoclimate, and evolution of the Lake Eyre Basin, and the Australian continent.

摘要

板内构造作用和大陆气候变化在干旱的艾尔湖盆地的演化中发挥着重要作用，艾尔湖盆地是世界上最大的内陆盆地之一，对许多澳大利亚人来说是一个具有经济、环境和文化意义的地方。就在盆地的主要河流之一，Cooper Creek，Yamma Yamma 湖 - 一个 20 公里 x 40 公里的短暂特征 - 捕获上游约 750 公里的沉积物，比盆地的最终基准水位高约 90 米 - Kati Thanda-艾尔湖。本文首次报道了这个现代短暂的普拉亚湖的沉积学和地貌演化。基于现场的沉积学、基于实验室的粒度分析、卫星图像解释、淹没频率图、水文数据和数字高程数据，用于解释沉积过程和湖泊的演变。结果表明，亚马湖亚马湖是一个长期存在的特征。演化主要受结构控制，主要湖泊三角洲随着时间的推移向西北迁移。第四纪河流、湖泊和风成沉积可能受板内构造控制，古海岸线可能是先前气候状况的残余特征。该沉积档案的年代测定可以提供有关艾尔湖盆地和澳大利亚大陆的历史、古气候和演化的重要信息。