Sediment accumulation, stratigraphic order, and the extent of time-averaging in lagoonal sediments: a comparison of 210Pb and 14C/amino acid racemization chronologies
Sediment accumulation, stratigraphic order, and the extent of time-averaging in lagoonal sediments: a comparison of 210Pb and 14C/amino acid racemization chronologies
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DOI：
10.1007/s00338-014-1234-2
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发表时间：
2015-03-01
期刊：
影响因子：
3.5
通讯作者：
Zawadzki, Atun
中科院分区：
文献类型：
--
作者：
Kosnik, Matthew A.;Hua, Quan;Zawadzki, Atun
碳-14校准氨基酸外消旋化（C-14/AAR）数据和铅-210 （Pb-210）数据用于检查从澳大利亚大堡礁南部的One Tree Reef泻湖收集的沉积物的沉积速率、地层顺序和时间平均程度。最上面一米的泻湖沉积物保存了过去600年来按地层顺序排列的沉积物。尽管有不同的假设，但Pb-210和C-14/AAR年表非常相似，表明沉积过程在超过三个数量级（0.1-10 mm）的沉积物粒度上具有一致性。长期沉积物积累速率的估计范围为每年2.2至1.2毫米（-1）。在埋藏活跃区，软体动物的平均时间为19年，而在最终埋藏深度（约15厘米）以下，平均时间为110年/5厘米。虽然不是一个高分辨率的古生物记录，但这个礁湖沉积物适合于跨越西部殖民和发展时期的古生态学研究。这种沉积沉积物，以及其他类似的沉积物，对于量化人类对珊瑚礁系统的影响应该是有用的，尽管不是理想的。
Carbon-14 calibrated amino acid racemization (C-14/AAR) data and lead-210 (Pb-210) data are used to examine sediment accumulation rates, stratigraphic order, and the extent of time-averaging in sediments collected from the One Tree Reef lagoon (southern Great Barrier Reef, Australia). The top meter of lagoonal sediment preserves a stratigraphically ordered deposit spanning the last 600 yrs. Despite different assumptions, the Pb-210 and C-14/AAR chronologies are remarkably similar indicating consistency in sedimentary processes across sediment grain sizes spanning more than three orders of magnitude (0.1-10 mm). Estimates of long-term sediment accumulation rates range from 2.2 to 1.2 mm yr(-1). Molluscan time-averaging in the taphonomically active zone is 19 yrs, whereas below the depth of final burial (similar to 15 cm), it is similar to 110 yrs/5 cm layer. While not a high-resolution paleontological record, this reef lagoon sediment is suitable for paleoecological studies spanning the period of Western colonization and development. This sedimentary deposit, and others like it, should be useful, albeit not ideal, for quantifying anthropogenic impacts on coral reef systems.