美国西部Owens湖地球化学记录及其古气候意义

被引:18
作者
李红春
朱照宇
机构
[1] 美国南加州大学地球科学系
[2] 中国科学院广州地球化学研究所 洛杉矶CA
[3] 广州
关键词
稳定同位素; 稀酸可溶相锂; Owens湖; 古气候;
D O I
暂无
中图分类号
P59 [地球化学];
学科分类号
070902 ;
摘要
美国加州中部Owens湖的稳定同位素、稀酸可溶相锂元素浓度及其它地球化学指标揭示本区 0 .15 5MaB .P .~ 6 2 5 0 0aB .P .间的气候变化。在 0 .15 5~ 0 .14 0MaB .P .,0 .12 2~0 .114MaB .P .,910 0 0~ 830 0 0aB .P .和 72 0 0 0~ 6 2 5 0 0aB .P .期间 ,气候冷湿 ,对应于深海氧同位素 (MIS) 6 ,5d ,5b和 4阶段。这些期间内湖泊开放 ,δ18O和δ13 C无协变性 ,Li和有机碳浓度很低。在 0 .14 0~ 0 .12 2MaB .P .,0 .114MaB .P .~ 910 0 0aB .P .和 830 0 0~ 72 0 0 0aB .P .期间 ,气候干热 ,对应于MIS5e ,5c和 5a阶段。湖泊在这些期间内封闭 ,δ18O和δ13 C有很好的协变性 ,封闭湖δ18O的变化代表了湖水体积的变化。来自湖中自生镁硅酸盐的锂元素浓度的变化反映了盐度和温度的变化。Owens湖的记录与DevilsHole洞穴流石记录和格陵兰冰芯记录有很好的对比 ,进一步证实了终结期Ⅱ在海相记录中的年龄滞后。本文讨论了冰期与间冰期之间 ,美国西部和中国黄土地区气候模式的差异及其互动机制。
引用
收藏
页码:578 / 588
页数:11
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