Mg-lattice associations in red coralline algae
Mg-lattice associations in red coralline algae
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DOI：
10.1016/j.gca.2009.01.010
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发表时间：
2009-04-01
影响因子：
5
通讯作者：
Scheibling, R. E.
中科院分区：
文献类型：
--
作者：
Kamenos, N. A.;Cusack, M.;Scheibling, R. E.
最近的研究表明，红珊瑚藻可以在其方解石骨架中记录环境温度。通过藻类生长带内镁浓度变化记录的温度具有亚年分辨率和高精度。 Mg 浓度到温度的转换是基于在较高温度下藻类方解石骨架中 Ca 被 Mg 取代的假设。虽然珊瑚藻中镁与温度的关系已针对某些物种进行了校准，但镁在方解石晶格中的位置仍然未知。重要的是，如果镁不是晶格成分而是与有机成分相关，则可能导致错误的温度记录。因此，在将珊瑚藻用于大规模气候重建之前，确定镁的位置非常重要。同步加速器 Mg-X 射线近边缘吸收结构 (XANES) 表明 Mg 与 Lithothamnion glaciale（当代自由生活、当代结壳和亚化石自由生活）和 Phymatolithon calcareum（当代自由生活）珊瑚藻中的方解石晶格有关。镁在所有季节（L. glaciale 和 P. calcareum）和叶状体区域（P. calcareum）中沉积在方解石晶格内。这些结果表明 L. glaciale 和 P. calcareum 是稳健的 Mg-古温度代理。我们建议对其他种类的红珊瑚藻中的镁关联进行类似的确认，以帮助我们了解它们在大空间尺度的气候重建中的作用。 (c) 2009 Elsevier Ltd. 保留所有权利。
Recent investigations have shown red coralline algae to record ambient temperature in their calcite skeletons. Temperature recorded by variation in Mg concentrations within algal growth bands has sub-annual resolution and high accuracy. The conversion of Mg concentration to temperature is based on the assumption of Ca replacement by Mg within the algal calcite skeleton at higher temperatures. While Mg-temperature relationships in coralline algae have been calibrated for some species, the location of Mg within the calcite lattice remains unknown. Critically, if Mg is not a lattice component but associated with organic components this could lead to erroneous temperature records. Before coralline algae are used in large scale climate reconstructions it is therefore important to determine the location of Mg. Synchrotron Mg-X-ray absorbance near edge structure (XANES) indicates that Mg is associated with the calcite lattice in Lithothamnion glaciale (contemporary free-living, contemporary encrusting and sub-fossil free-living) and Phymatolithon calcareum (contemporary free-living) coralline algae. Mg is deposited within the calcite lattice in all seasons (L. glaciale & P. calcareum) and thallus areas (P. calcareum). These results suggest L. glaciale and P. calcareum are robust Mg-palaeoternperature proxies. We suggest that similar confirmation be obtained for Mg associations in other species of red coralline algae aiding our understanding of their role in climate reconstruction at large spatial scales. (c) 2009 Elsevier Ltd. All rights reserved.