Barite in the Central Equatorial Pacific: Implications for Marine Chemistry, Productivity, and Circulation of the Modern and Past Oceans

赤道中部太平洋的重晶石：对海洋化学、生产力以及现代和过去海洋环流的影响

• 批准号: 9116010
• 负责人: Miriam Kastner
• 金额: $ 16.97万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-12-15 至 1994-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9116010&HistoricalAwards=false
• 关键词: Barite; Central; Equatorial; Pacific; Implications

The mineral barite BaSO4) is an ubiquitous component of particulate material in the water column, and of pelagic sediments. Many workers have noted a correlation between the abundance of barite in sediments and productivity in overlying surface waters. Barite is clearly important in the geochemical cycle of Ba, and it is also quite insoluble and therefore resists dissolution and diagenetic exchange in sediments. Furthermore, three elements for which the seawater isotopic composition is important for solving many paleoceanographic problems (Sr, S and Nd) occur in barite in amounts that permit precise isotopic measurements to be made on very small amounts of the separated phase. For all of these reasons, barite appears to be an important tracer of productivity, geochemical cycling, and a host of processes that may affect seawater chemical and isotopic compositions, e.g. climate, tectonics, sealevel change and rates of marine hydrothermal activity. Nevertheless, the present understanding of the sites and mechanisms of barite formation, transport, and fate in the sedimentary column is very incomplete and the linkage between Ba, barite and C fluxes need to be clarified. In this research a mass- balance, morphological, geochemical and isotopic approach to the study of the cycling of barite in upper sedimentary layers of the equatorial Pacific and its relation to the C cycling will be made Novel aspects of the work include the use of Nd, Sr and S isotopes as clues to the environment of formation and possible recycling of barite. This study will make use of sediment trap, filtered and bottom sediment samples, and will be closely coordinated with geochemical and isotopic investigations of the water column by other workers. It will also be undertaken with close attention to the potential of barite as a contemporary as well as a paleo monitor of biogeochemical and isotopic characteristics of seawater.

重晶石（BaSO 4）是一种普遍存在的颗粒物成分， 水体中的物质和远洋沉积物。 许多 研究人员注意到， 沉积物和上覆地表沃茨的生产力。 重晶石 在Ba的地球化学循环中显然很重要，它也是 非常不溶，因此抵抗溶解和成岩作用 交换沉积物。 此外，三个要素， 海水同位素组成对于解决许多 古海洋学问题（Sr，S和Nd）发生在重晶石中， 量，允许精确的同位素测量， 非常少量的分离相。 对于所有这些 因此，重晶石似乎是生产力的重要示踪剂， 地球化学循环，以及一系列可能影响 海水化学和同位素组成，例如气候， 构造、海平面变化和海洋热液速率 活动 尽管如此，目前对这些遗址的了解和 机制的重晶石形成，运输，和命运的 沉积柱非常不完整， 重晶石和C通量需要澄清。 在这项研究中，一个质量- 平衡，形态，地球化学和同位素的方法， 塔里木盆地上部沉积层中重晶石的循环研究 赤道太平洋及其与C循环的关系 这项工作的新方面包括使用Nd、Sr和S同位素 作为线索的形成环境和可能的回收利用 重晶石。 这项研究将利用沉积物收集器，过滤， 海底沉积物样品，并将与 对水柱进行了地球化学和同位素调查， 其他工人。 还将密切注意以下方面： 重晶石作为现代和古生物的潜力 监测海水的地球化学和同位素特征。