PDF
Full
Outline
In this study, elemental and mineral compositions of three surface sediments collected from the South Atlantic Ridge affected by hydrothermal activities of various degrees were analyzed, and series of extraction experiments for carbonate phase, Fe-Mn oxide phase and insoluble residual phase were carried out. Mixed reagent of hydroxylamine hydrochloride (HH) with different concentrations and 25% acetic acid (HAc) were used to extract Fe-Mn oxide phase from the sample. In order to corroborate the reliability of the extracting methods, Ti/Nd and Ti/Pb ratios of the Fe-Mn oxide phase, rare earth elements (REE) patterns as well as δCe and δEu ratios of different chemical phase were used to determine that the ideal reagent conditions for extracting Fe-Mn oxide phase from three different types of hydrothermal sediments were all 0.5 mol/L HH in 25% acetic acid. The results show that the higher the degree of influence of hydrothermal activities, the higher the contents of Fe, Cu, Zn and other elements in the sediments, and the contents of Ca, Sr and Ba show an opposite trend. Manganese, Pb and REE are not significantly affected by hydrothermal activities. As the influence of hydrothermal activity increases, the proportion of Ca, Sr and Nd increases in the Fe-Mn oxide phase and decreases in the residual phase, while Mn, Co, Ni and Zn have an opposite trend, and the proportion of Cu increases in the carbonate phase and decreases in the residual phase. Lead is not affected by the influence strength of hydrothermal activity and mainly occurs in the Fe-Mn oxide phase. REE mainly occur in the residue state. The occurrence state of REE shows that the more significant influence by the hydrothermal activities of the sediments, the more enrichment of REE in the residual phase. And the chondrite-normalized REE patterns of the residual phase exhibit that the enrichment of light REE are less obvious. This study provides methods for extracting hydrothermal fractions and valuable geochemical data for further understanding of the characteristics of hydrothermal sediments and the effects of hydrothermal activities on the occurrence state of elements in the South Atlantic Ridge.
PDF
170
75
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
