Noble gases in Lakes Nyos and Monoun, Cameroon.
Noble gases in Lakes Nyos and Monoun, Cameroon.
复制标题
喀麦隆尼奥斯湖和莫翁湖中的稀有气体。
DOI：
10.2343/geochemj.1.0101
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发表时间：
2010
影响因子：
0.8
通讯作者：
G. Tanyileke
中科院分区：
文献类型：
--
作者：
K. Nagao;M. Kusakabe;Y. Yoshida;G. Tanyileke
对西非喀麦隆Nyos湖和Monoun湖不同深度稀有气体的He、Ne和Ar同位素比值和浓度进行了研究。样本分别于一九九九年十一月、二零零一年一月及二零零一年十二月收集。2001年采用改进的采样方法，使我们能够检测到详细的同位素分布在湖泊。湖水沃茨中Ne和N2浓度分别比空气饱和水（ASW）低约10倍和3倍，而CO2气体中Ne和N2浓度比空气中低2个数量级。相比之下，He在湖水中的富集程度比ASW高出三个数量级以上。3 He/ 4 He比值为8 × 10 - 6（尼奥斯湖）和5 × 10 - 6（莫农湖），表明地幔起源的岩浆气体向湖泊的补给，尽管该比值因来自地壳岩石的放射成因4 He的加入而降低。在两个湖沃茨中均检测到小的MORB样Ne贡献（<2%）。两个端部构件之间的简单混合，即，大气和来自深层储层的气体，可以解释惰性气体的特征。Nyos湖He浓度的深度剖面显示出明显的分层结构，最大值出现在190 m处，距湖底20 m处。在此深度以下，3 He/ 4 He比值略有下降，表明来自深部储层的流体主要在约1000 m处向湖泊提供。一百九十米。尼奥斯湖深层和浅层的C/ 3 He比值分别为1.5 × 1010和0.6 × 1010。C/ 3 He比值为1.7 × 1010，
He, Ne and Ar isotopic ratios and concentrations of noble gases in different depths of Lakes Nyos and Monoun in Cameroon, West Africa, were investigated. Samples were collected in November 1999, January 2001 and December 2001. Improved sampling method applied in 2001 enabled us to detect detailed isotopic distribution in the lakes. Concentrations of Ne and Xe in the lake waters were low by factors of ~10 and ~3, respectively, compared with those of air saturated water (ASW), whereas in CO 2 gas they were depleted by 2 orders of magnitude compared with those in air. In contrast, He was strongly enriched in lake water by more than three orders of magnitude compared to ASW. 3 He/ 4 He ratios of 8 × 10 ‐6 (Lake Nyos) and 5 × 10 ‐6 (Lake Monoun) indicated recharge of magmatic gases of mantle origin to the lakes, though the ratios were lowered by the addition of radiogenic 4 He from crustal rocks. A small contribution (<2%) of MORB-like Ne was detected in both lake waters. A simple mixing between two end members, i.e., atmosphere and gases from a deepseated reservoir, can explain the noble gas signatures. Depth profile of He concentration in Lake Nyos showed a clear layered structure with a maximum at 190 m, 20 m above the lake bottom. Below this depth, 3 He/ 4 He ratio decreased slightly, suggesting that the fluid from the deep-seated reservoir is supplied to the lake mainly at ca. 190 m. C/ 3 He ratios were 1.5 × 10 10 and 0.6 × 10 10 in deep and shallow layers of Lake Nyos, respectively. The C/ 3 He ratio was 1.7 × 10 10 at
喀麦隆莫翁湖和尼奥斯湖受控脱气之前和期间 C0_2 的演变
DOI：
--
发表时间：
2008
期刊：
Geochemical Journal 42
影响因子：
--
作者：
M. Kusakabe;他
通讯作者：
他
影响因子：
3.9
作者：
Aka, FT;Nagao, K;Hell, J
通讯作者：
Hell, J
影响因子：
0.8
作者：
Matsuda, J;Matsumoto, T;Sano, Y
通讯作者：
Sano, Y