Whole-Rock Aminostratigraphy and Quaternary Sea-Level History of the Bahamas
Whole-Rock Aminostratigraphy and Quaternary Sea-Level History of the Bahamas
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巴哈马的全岩氨基地层学和第四纪海平面历史
DOI：
10.1006/qres.2000.2164
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发表时间：
2000
影响因子：
2.3
通讯作者：
D. Kaufman
中科院分区：
文献类型：
--
作者：
P. Hearty;D. Kaufman
构造稳定的巴哈马群岛的表层地质保存了世界上最完整的中晚第四纪海平面高水位周期记录之一。然而，除了海洋同位素亚阶段（MIS）5e的沉积物外，用于这一丰富地层序列放射性测年的珊瑚化石很少。本研究利用以前发表的，独立的岩石地层框架作为试验场的氨基酸外消旋在全岩石灰岩样品。至少有六个石灰岩土壤偶提供了一个相对的年龄序列的事件，包括尽可能多的间冰期-冰期循环。D-别异亮氨酸/L-异亮氨酸数据分为六个簇，或“氨基带”。在独立定年和与全球MIS的推断相关性的基础上，已知几个氨基带的年龄，而其他氨基带的年龄则根据校准的氨基酸地质年代学计算。这项研究证明了全岩氨基地层学方法的实用性，用于测定和关联广泛的新兴海洋沉积物，构成了巴哈马的第一个区域地质年代学框架，并突出了过去50万年来的主要海平面事件。
The surficial geology of the tectonically stable Bahamian archipelago preserves one of the most complete records of middle to late Quaternary sea-level-highstand cycles in the world. However, with the exception of deposits from marine isotope substage (MIS) 5e, fossil corals for radiometric dating of this rich stratigraphic sequence are rare. This study utilizes the previously published, independent lithostratigraphic framework as a testing ground for amino acid racemization in whole-rock limestone samples. At least six limestone–soil couplets provide a relative age sequence of events that encompass as many interglacial–glacial cycles. D-Alloisoleucine/L-isoleucine data fall into six clusters, or “aminozones.” On the basis of independent dating and the inferred correlation with global MIS, the ages of several aminozones are known, while the ages of others are calculated from calibrated amino acid geochronology. This study demonstrates the utility of the whole-rock aminostratigraphy method for dating and correlating widespread emergent marine deposits, constitutes the first regional geochronological framework for the Bahamas, and highlights major sea-level events over the past half million years.