Microscale magnesium distribution in shell of the Mediterranean mussel Mytilus galloprovincialis: An example of multiple factors controlling Mg/Ca in biogenic calcite
Microscale magnesium distribution in shell of the Mediterranean mussel Mytilus galloprovincialis: An example of multiple factors controlling Mg/Ca in biogenic calcite
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DOI：
10.1016/j.chemgeo.2018.10.025
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发表时间：
2019-04-20
期刊：
影响因子：
3.9
通讯作者：
Shirai, Kotaro
中科院分区：
文献类型：
--
作者：
Tanaka, Kentaro;Okaniwa, Nobuyuki;Shirai, Kotaro
由于镁浓度（Mg/Ca）在生物方解石被认为是反映在降水过程中的水温，镁钙比已被检查作为古气候研究中的水温代理，虽然温度以外的因素也可能会影响Mg/Ca在生物方解石，从而引入一个潜在的偏差在无机系统中观察到的Mg/Ca和温度之间的关系。为了更好地了解Mg进入双壳类方解石壳的控制因素，研究了Mg在地中海贻贝Mytilus galloprovincialis中的分布，并与环境海水表面温度（SST）、壳生长速率和有机质分布进行了比较。虽然观察到Mg/Ca和SST之间的正相关关系，Mg/Ca已受到其他因素的影响，包括增强镁掺入有机质，证明了生长线更富镁比生长增量。此外，镁/钙是相对丰富的起伏（较高的曲率）壳部分，与SST，生长速度或有机质。分区的Mg 2 +/Ca 2+的extrapalial流体在起伏的壳部分形成的时间被假设，和异质镁分布在同期形成的壳部分的结论是限制贻贝壳镁/钙作为水温的代理的可用性。
Since magnesium concentration (Mg/Ca) in biogenic calcite is considered to reflect water temperature during precipitation, the magnesium-to-calcium ratio has been examined as a proxy for water temperature in paleo-climate research, although factors other than temperature may also influence Mg/Ca in biogenic calcite, thereby introducing a potential bias in the relationship between Mg/Ca and temperature observed in inorganic systems. To better understand factors controlling Mg incorporation into the calcitic shells of bivalves, the distribution of Mg in the Mediterranean mussel Mytilus galloprovincialis was studied, being compared with ambient sea surface temperature (SST), shell growth rate and the distribution of organic matter. Although a positive relationship between Mg/Ca and SST was observed, Mg/Ca had been influenced by additional factors, including the enhancement of Mg incorporation by organic matter, evidenced by the growth line being more Mg-enriched than the growth increments. Furthermore, Mg/Ca was relatively enriched in the undulating (higher curvature) shell portion, being linked to neither SST, growth rate or organic matter. Zoning of Mg2+/Ca2+ within extrapallial fluid at the time of undulating shell portion formation was hypothesized, and heterogeneous Mg distribution in contemporaneously formed shell portions concluded as limiting the usability of Mytilus shell Mg/Ca as a proxy for water temperature.