CONSTANCY OF OCEANIC DEPOSITION OF BE-10 AS RECORDED IN MANGANESE CRUSTS
CONSTANCY OF OCEANIC DEPOSITION OF BE-10 AS RECORDED IN MANGANESE CRUSTS
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DOI：
10.1038/299240a0
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发表时间：
1982-01-01
期刊：
影响因子：
64.8
通讯作者：
NOWIKOW, I
中科院分区：
文献类型：
--
作者：
KU, TL;KUSAKABE, M;NOWIKOW, I
在使用核加速器作为高能质谱仪方面的最新进展1，2重新引起了人们对宇宙起源10Be(半衰期1.5Myr)作为地球物理时间示踪剂的研究兴趣。加速器技术使我们能够以107个原子或更少的灵敏度测量10Be。如果10Be的生产和沉积速率在这段时间内保持不变或几乎不变，那么10Be的潜在年龄跨度被延长到至少15MyrBP。因此，了解10Be沉积速率的长期稳定性是非常重要的。本文报道了赤道大西洋海底两个氧化铁结壳中10Be和9Be的首次详细测量。K-9-21)和北太平洋(SCHW-1D)，每一个都代表了>；10Myr的聚集史。我们在这些结壳中发现，10Be和10Be/9Be在过去7-9Myr期间的沉积是恒定的。在∼1Myr的时间间隔上平均，变异在±6%以内。在此之前，两个结壳都显示出类似的显著偏差。7-9 MIR的划分可能与报道的晚中新世全球深海环流变化有关。
Recent developments in the use of nuclear accelerators as high-energy mass spectrometers1,2has renewed interest in the study of cosmogenic10Be (half life 1.5 Myr) as a geophysical time tracer. The accelerator techniques enable us to measure10Be with a sensitivity of 107atoms or less. The potential age dating span with10Be is extended back to at least 15 MyrBP, providing that the10Be production and deposition rates remain constant or nearly constant over that time period. A knowledge of the long-term constancy in the10Be deposition rate is thus very important. We report here the first detailed measurements of10Be and9Be in two ferromanganese oxide crusts from the sea floor of the equatorial Atlantic (sample no. K-9-21) and the North Pacific (SCHW-1D), each representing >10 Myr of accumulation history. We have found in these crusts that the deposition of10Be and10Be/9Be during the past 7–9 Myr has been constant. Averaged over time intervals of ∼1 Myr, the variation is within ±6%. Before that time, both crusts show similar significant deviations. The 7–9 Myr demarcation may be related to the reported late Miocene global abyssal circulation change in the ocean3.