Trace Metals in Closed-Basin Lake Sediments: Reactions During Early Diagenesis

闭盆湖泊沉积物中的微量金属：早期成岩作用过程中的反应

• 批准号: 8706384
• 负责人: Sakiko Olsen
• 金额: $ 9.76万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1989-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8706384&HistoricalAwards=false
• 关键词: Trace; Metals; Closed; Basin; Lake

The processes by which trace metals such as FE, Mn, Cu, Pb, Zn, Mo, V, Cd and Co are incorporated into organic-rich sediments of saline lakes will be elucidated by studying three contrasting closed basins: Great Salt Lake, Utah, Mono Lake, Cal. and Walker Lake, Nevada. Great Salt Lake bottom waters are anoxic and consist of concentrated sulfate enriched brines, Mono Lake is highly productive and alkaline, with carbonate-enriched brines and an anoxic sediment sulfate. Walker Lake is alkaline, but less concentrated and less productive, and its sediment-water interface is only temporarily anoxic. Lake waters, pore fluids and sediment to 1 meter depth are to be analyzed and studied with special emphasis on metal complexing by organic matter, such as humic substances. Preliminary data suggest that at Great Salt Lake metals are precipitated as sulfides in the hypolimnion. At Mono Lake, metals are mobilized very near the sediment surface. Within the sediment, hydrogen sulfide production is high and metals are precipitated. At Walker Lake, an oxy-hydroxyde layer is formed at the sediment-water interface. A molybdenum maximum exists in the pore fluids at 10 cm and in the sediments at 15 cm depth, indicating considerable metal redistribution in response to redox changes. A comparison of metal distribution between lake waters, pore fluids and sediment in these three contrasting sites promises to provide significant insights into metal accumulation in black shles and oil shales deposited in saline lacustrine settings.

微量金属如铁、锰、铜、 Pb、Zn、Mo、V、Cd、Co等元素被有机质富集 盐湖沉积物将通过研究三个 对比封闭盆地：大盐湖，犹他州，莫诺湖， 卡尔和步行者湖，内华达州。 大盐湖底部沃茨 是缺氧的，由浓缩的硫酸盐组成， 莫诺湖是一个高生产力和碱性， 富含碳酸盐的盐水和缺氧沉积物硫酸盐。 步行者湖是碱性的，但浓度较低， 多产，其沉积物-水界面只是暂时的 缺氧 湖沃茨、孔隙流体和沉积物至1米深 将特别侧重于金属的分析和研究 被有机物络合，如腐殖物质。 初步数据表明，在大盐湖， 以硫化物的形式沉淀在下层水中。 在莫诺湖 金属在非常靠近沉积物表面的地方被移动。 内 沉积物中，硫化氢的产量很高， 是沉淀的。 在步行者湖， 形成于沉积物-水界面。 一个钼最大值 10 cm处存在于孔隙流体中，15 cm处存在于沉积物中 厘米深，表明相当大的金属重新分布， 对氧化还原变化的反应。 金属分布的比较 在这三个区域中，湖泊沃茨、孔隙流体和沉积物之间存在着 对比网站承诺提供重要的见解， 金属在黑色页岩和油页岩中的积累， 咸水湖环境