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对中太平洋MH海山富钴结壳不同壳层样品的稀有气体同位素丰度与组成测定结果表明:富钴结壳中He同位素组成类似于深海沉积物,主要来源于宇宙尘,其3He含量由老到新呈现基本稳定的特征,但在8Ma时3He含量明显增加,是其他样品的4～5倍,与深海沉积物中3He含量在8Ma达到最大值相吻合.在未磷酸盐化壳层中,D4、D5、D7的3He/4He比值也与深海沉积物的3He/4He比值(n×102Ra)相当.磷酸盐化壳层中3He/4He比值相对较低,是由于磷酸盐化过程中生成的碳氟磷灰石中富集4He而贫3He,从而引起磷酸盐化壳层中4He含量明显增加,导致磷酸盐化壳层3He/4He比值降低.结壳中结构相对疏松的壳层有利于对Ar的吸附,大部分Ar可能是在结壳生长过程中从周围海水中直接吸附到结壳中的.
The abundance and composition of rare gas isotopes in different crust samples of cobalt-rich crusts in MH seamount in the Central Pacific Ocean show that the He isotope composition of cobalt-rich crusts is similar to that of deep-sea sediments, mainly from cosmic dust with 3He content To the newly presented basic stable features, but at 8Ma 3He content increased significantly, compared with other samples 4 to 5 times, and 3He content in deep-sea sediment in 8Ma to reach the maximum value in the unphosphated shell, The 3He / 4He ratios of D4, D5 and D7 are also comparable with the 3He / 4He ratios of deep sea sediments (n × 102Ra). The relatively low 3He / 4He ratio in the phosphated shells is due to the formation of The enrichment of 4He and lean 3He in the fluorocarbon apatite caused a significant increase of the 4He content in the phosphated shell, resulting in a decrease in the 3He / 4He ratio of the phosphated shell.The relatively loosely packed shell in the crust favored the reduction of Ar Adsorption, most of the Ar may be adsorbed directly into the crust from the surrounding seawater during crustal growth.