The identification and correlation of a sequence of Pleistocene beach barriers located within the northern Coorong Coastal Plain, South Australia, is made difficult by long-term subsidence and extensive reworking. Associated shell beds, to all but the last interglacial barrier, are subsurface and not readily accessible. The whole-rock amino acid racemization method was found to be unsuitable for distinguishing age differences of the individual barriers due to the low calcium carbonate content of the sediments, concerns for the leaching or contamination as a result of the comminuted nature of the shelly component, and the potentially high content of reworked sediment. These difficulties prompted an investigation into the applicability of AAR analysis of single foraminifera tests to ascertain whether the relative age of beach barriers could be determined and whether sediment contribution from antecedent barriers could be identified. Foraminifera tests of multiple genera (including Cibicides corticatus and Rosalina bradyi) from numerous modern depositional environments were analyzed to establish aminozones of aspartic acid and glutamic acid D/L values representative of modern/Holocene foraminifera and to assess natural variability of Holocene D/L values between depositional settings. Tests of Lamellodiscorbis dimidiatus, common in the Pleistocene barriers, were analyzed from MIS 5 and MIS 7 sediments and aminozones identified, allowing correlation of non-contiguous barrier features and the identification of reworked foraminifera. Rejection criteria removed, on average, between 25 and 30% of analytical results. The Holocene aminozone for every genus analyzed falls within the same general constraint: D/L values less than 0.40 for aspartic acid and less than 0.20 for glutamic acid. The D/L values of approximately 15% of foraminifera from the modern sediments exceed the Holocene aminozone constraint and the tests are considered reworked. The range of D/L values representative of each interglacial aminozone decreases with age, reflecting the slowing rate of amino acid racemization with time. Pleistocene sediments are found to have a higher percentage of reworked tests. Thermoluminescence dating of the Pleistocene successions was used to evaluate the AAR results. This work illustrates that foraminifera tests are surprisingly robust and can survive potentially multiple phases of deposition and reworking.

长期沉降和大量返工使位于南澳大利亚北部Coorong沿海平原内的一系列更新世海滩屏障的识别和关联变得困难。除最后一个冰缘屏障外，所有带壳的贝壳床都在地下并且不易接近。由于沉积物中碳酸钙含量低，由于贝壳成分的粉碎性质而导致的浸出或污染，全岩石氨基酸消旋法被认为不适用于区分各个屏障的年龄差异。以及返工沉积物的潜在高含量。这些困难促使人们对单个有孔虫测试的AAR分析的适用性进行调查，以确定是否可以确定海滩屏障的相对年龄，以及是否可以确定先前屏障的沉积物贡献。多属有孔虫测试（包括分析了来自许多现代沉积环境的粉虱和蔷薇蔷薇（Rosalina bradyi），以建立代表现代/全新有孔虫的天冬氨酸和谷氨酸D / L值的氨基区域，并评估沉积环境之间全新世D / L值的自然变异性。Lamellodiscorbis dimidiatus的测试从MIS 5和MIS 7沉积物和已识别的氨基带中分析了更新世屏障中常见的，从而实现了非连续屏障特征的关联和返工的有孔虫的识别。平均而言，剔除标准消除了分析结果的25％至30％。每种分析属的全新世氨基区都属于相同的一般约束条件：天冬氨酸的D / L值小于0.40，谷氨酸的D / L值小于0.20。来自现代沉积物的有孔虫的D / L值约为15％，超过了全新世的氨基带限制，并且测试被认为是重做的。代表每个冰川间氨基带的D / L值的范围随年龄的增长而减小，反映出氨基酸外消旋化的速度随时间而降低。发现更新世沉积物的返工测试比例更高。更新世演替的热致发光年代用来评估AAR结果。这项工作说明，有孔虫测试出奇地强大，并且可以在沉积和返工的多个阶段中幸存下来。