林震, 于洪军, 徐兴永, 杨继超, 易亮, 付腾飞, 吕文哲. 西南印度洋中脊扩张轴部(34.9°S)西翼沉积物地球化学分析及物源探讨[J]. 海洋地质与第四纪地质, 2018, 38(5): 14-29. DOI: 10.16562/j.cnki.0256-1492.2018.05.002
引用本文: 林震, 于洪军, 徐兴永, 杨继超, 易亮, 付腾飞, 吕文哲. 西南印度洋中脊扩张轴部(34.9°S)西翼沉积物地球化学分析及物源探讨[J]. 海洋地质与第四纪地质, 2018, 38(5): 14-29. DOI: 10.16562/j.cnki.0256-1492.2018.05.002
LIN Zhen, YU Hongjun, XU Xingyong, YANG Jichao, YI Liang, FU Tengfei, LV Wenzhe. Geochemistry and provenance of the sediment from the west flank of the spreading southwest Indian Oceanic Ridge (34.9°S)[J]. Marine Geology & Quaternary Geology, 2018, 38(5): 14-29. DOI: 10.16562/j.cnki.0256-1492.2018.05.002
Citation: LIN Zhen, YU Hongjun, XU Xingyong, YANG Jichao, YI Liang, FU Tengfei, LV Wenzhe. Geochemistry and provenance of the sediment from the west flank of the spreading southwest Indian Oceanic Ridge (34.9°S)[J]. Marine Geology & Quaternary Geology, 2018, 38(5): 14-29. DOI: 10.16562/j.cnki.0256-1492.2018.05.002

西南印度洋中脊扩张轴部(34.9°S)西翼沉积物地球化学分析及物源探讨

Geochemistry and provenance of the sediment from the west flank of the spreading southwest Indian Oceanic Ridge (34.9°S)

  • 摘要: 西南印度洋中脊沉积物来源广泛,是区域海洋环境演化的记录器,对其沉积物特征及物源研究是区域古海洋研究的基础。对采自西南印度洋中脊扩张轴部(34.9°S)西翼的重力柱沉积物样品进行总碳、总有机碳、生物硅、主量元素、微量及稀土元素测试, 测试结果显示,样品中生物成因组分为沉积物的主要组成,主要包括碳酸盐和二氧化硅;主微量元素除了Ca、Sr与LOI外,其余元素的分布趋势基本一致,且相关系数基本大于0.8。结合不同生物组分特点进行分析计算,获得了沉积物中各生物组分的含量。去除生物成因组分重新计算了非生物成因元素含量,通过潜在物源及相应地球化学指标对比分析,发现非生物成因组分主要由非洲南部风成陆源物质组成,含少量洋中脊硫化物与结壳物质。

     

    Abstract: The multi-origin sediments on the southwest Indian Ridge (SWIR) are the archive of environmental evolution of the region. The study of sediment characteristics and provenances founded the basis of paleoceanographic study. In this paper, we analyzed the deep-sea sediment samples from a gravity core sampled at 34.9°S on the spreading SWIR, and a comprehensive data set was constructed for their bulk chemical compositions, including major elements, trace elements, and bio-components. As the data show, the bulk samples are dominated by bio-components, consisting of high bio-carbonate and low bio-silica. The distribution patterns of major elements are rather accordant. Except for Ca, Sr, and LOI, the correlation coefficient of other major elements are greater than 0.8. Based on the properties of bio-components of sediment, we computed the weight percentage of each bio-component. Removed the bio-components from the bulk, we recalculated the weight percentage of non-biotic elements. The data is used as geochemical proxies to study the potential sources. It is found that the abiotic component of the sediment is mainly terrestrial and local origin. The primary source is the aeolian dust from southern Africa, with a small amount of deposits from hydrothermal sulfide and manganese crust.

     

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