¹⁰Be spikes in Plio–Pleistocene cyclothems, Wanganui Basin, New Zealand: identification of the local flooding surface (LFS)

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• 作者：Graham ; Ian J. ; Ditchburn ; Robert G. ; Whitehead ; Neil E.
• 关键词：Wanganui Basin ; sequence stratigraphy ; Quaternary ; local flooding surface ; ¹⁰Be
• 刊名：Sedimentary Geology
• 出版年：1998
• 期刊代码：81_00370738
• 类别：ear
• 出版时间：December, 1998
• 卷：122
• 期：1-4
• 页码：193-215
• 文件大小：670 K

摘要

Marine shelf sediments of the Wanganui Basin (Castlecliff section) spanning oxygen isotope stages 21–17 (ca. 920–680 ka) contain spikes of enriched ¹⁰Be concentrations (and enhanced ¹⁰Be/⁹Be ratios), up to 10× ‘background' values. The ¹⁰Be spikes do not coincide precisely with peaks in carbonate content and grainsize, or with changes in bulk rock chemical composition. Rather, they appear in the sequence a little above the base of each cyclothem, at the presumed location of the local flooding surface (LFS). They therefore originated in response to seafloor sediment starvation during transgression, and not from ice sheet melting, biogenic scavenging or geomagnetic intensity changes, as has been suggested previously for ¹⁰Be spikes in some deep-sea or continental margin sequences.