浮游有孔虫壳体重量的古海洋学应用  

Paleoceanographic applications of planktonic foraminiferal shell weights

作　　者：秦秉斌 熊志方 李铁刚 QIN Bingbin;XIONG Zhifang;LI Tiegang(Key Laboratory of Marine Geology and Metallogeny,First Institute of Oceanography,Ministry of Natural Resources,Qingdao 266061,China;Laboratory for Marine Geology,Laoshan Laboratory,Qingdao 266237,China)

机构地区：[1]自然资源部第一海洋研究所海洋地质与成矿作用重点实验室,青岛266061 [2]崂山实验室海洋地质过程与环境功能实验室,青岛266237

出　　处：《海洋地质与第四纪地质》2023年第4期1-9,共9页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金重点项目“晚中新世以来印度洋-太平洋暖池水体交换过程及其气候效应”(41830539)。

摘　　要：海洋沉积物中浮游有孔虫壳体重量同时受到上层海洋钙化过程和深海碳酸钙溶解作用的影响,是一种潜在的古海洋代用指标。基于全球大洋表层沉积物的指标现代过程校准,发现当深海碳酸根离子饱和度<20μmol·kg-1,溶解作用开始显著影响浮游有孔虫壳体重量。易溶种的壳体重量对碳酸根离子饱和度的响应更加敏感,可以作为可靠的深海碳酸根离子饱和度代用指标。当深海碳酸根离子饱和度>20μmol·kg-1,浮游有孔虫壳体重量可反映其钙化程度。基于该指标的古海洋学研究揭示了冰期旋回中浮游有孔虫钙化过程主要响应海水碳酸盐系统和温度变化;上新世以来太平洋深海碳酸根离子饱和度演化主要受控于海平面、南大洋冰盖/海冰和全球温盐环流变化。浮游有孔虫壳体重量指标为探索海洋碳循环演化提供了有力工具。The shell weights of planktonic foraminifera from marine sediments are influenced by both upper-ocean calcification and deep-ocean calcium carbonate dissolution,and are potential paleoceanographic proxies.Based on the global surface-sediment calibrations,dissolution begins to significantly affect planktonic foraminiferal shell weight when the deep-ocean carbonate ion saturation degree(CISD)is below 20μmol·kg^(−1).The shell weights of dissolution-susceptible species are more sensitive to CISD changes,and thus can be used as reliable deepocean CISD proxies.When the deep-ocean CISD is above 20μmol·kg^(−1),the shell weights of planktonic foraminifera can reflect the changes of their calcification degree.Previous paleoceanographic studies based on the shell weight proxies reveal that the calcifications of planktonic foraminifera mainly respond to the changes in seawater carbonate system and temperature during glacial-interglacial cycles.The evolutions of deep Pacific CISD since the Pliocene is controlled by the changes in sea level height,Southern Ocean ice-sheet/sea ice,and global thermohaline circulation.The planktonic foraminiferal shell weight proxy provides a powerful tool for exploring the evolution of ocean carbon cycle.

关 键 词：表层沉积物 钙化作用 溶解作用 碳酸根离子饱和度 海洋碳循环 

分 类 号：P736[天文地球—海洋地质]