南沙群岛永暑礁区近百万年来的古气候变化——南永1井的锰含量分析

PALEOCLIMATIC VARIATION OF YONGSHU REEF IN NANSHA ISLANDS OVER THE PAST MILLION YEARS——AN ANALYSIS ON MANGANESE CONTENT OF CORE NANYONG-1

用锰含量的变化,将南永1井岩心划分为21个锰阶段,与洛川黄土、深海沉积物、柴达木盆地察尔汗盐湖的气候旋回进行对比,在布容、松山极性期界线(730ka)以上,存在9次气候旋回,锰含量相对高的奇数阶段代表相对湿热的气候环境,而偶数阶段代表相对干冷的气候。Mn/Ca和Cd/Ca比值的正异常段反映三期(Q_1,Q_2,Q_3)围区的火山活动影响。锰的变化反映全球性的气候事件和本地区的局部地质事件。

According to their variation in Mn content, the core Nanyong-1 is divided into 21 manganese sections. By comparison to the climatic cycle of loess,deep sea sediments and Qarhan salt lake of Qaidam basin, 9 climatic cycles are found above the Brunhes, Matsuyama chron boundary (730 ka). The odd number sections with relative high manganese content represent a relative wetwarm climatic environment, while even number sections represent relative dry-cold climates. Positive anomalous Mn/Ca and Cd/Ca reflect three periods of volcanic activity enclosed areas. The variation in manganese reflects global climatic events and local geological events in the area.