用HPGeγ谱方法测定了一个采集自东太平洋的沉积物岩心的~(230)Th和~(231)Pa。对其深度分布规律及其所揭示的海洋学意义进行了研究,用~(230)Th_(ex)、~(231)Pa_(ex)和~(231)Pa_(ex)/~(230)Th_(ex)法计算得到完全一致的沉积速率,平均值为1.6 mm/ka。用~(231)Pa_(ex)/~(230)Th_(ex)比值法研究了100 ka时间尺度海洋输出生产力的变化,给出60~80 ka BP期间研究海域有高的输出生产力。
【英文摘要】
~(230)Th and ~(231)Pa contents of a sediment core collected from eastern Pacific were measured using HPGe γ spectrometry and researches were done for their depth distribution and oceanographic significance. The sedimentation rates evaluated based on ~(230)Th_(ex)、~(231)Pa_(ex) and ~(231)Pa_(ex)/~(230)Th_(ex) are in very good agreement. The average is 1. 6 mm/ka. The export productivity in the time range from 100 ka BP to datewas studied by means of ~(231)Pa_(ex)/ ~(230)Th_(ex) and a high export production d...
【基金】
大洋矿产资源开发协会“九五”国家专项基金项目(编号DY95-02-15)资助成果
【更新日期】
2010-12-23
【分类号】
P736.2
【正文快照】
230Th和’3lPa已广泛用于深海沉积速率与多金属结核生长速率的测定(库兹涅佐夫,1981;Krish-naswami et al.,1 982;Huh et al.,1984;Ivaniviehet al.,1 992;邹汉阳等,1988)。23oTh、23‘Pa是公认的颗粒活性核素,海水中几近均匀分布的234U和’35U衰变产生’30Th和“31Pa,它们极易