Benthic Mineralization of Organic Matter on the Continental Rise and the Dissolution of CaCO 3 at the Deep Sea Floor

大陆隆升过程中有机物的底栖矿化和深海海底 CaCO 3 的溶解

• 批准号: 9201896
• 负责人: Richard Jahnke
• 金额: --
• 依托单位: Skidaway Institute of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-01-01 至 1996-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9201896&HistoricalAwards=false
• 关键词: Benthic; Mineralization; Organic; Matter; Continental

This project is a continuation of a study of the cycling and diagenesis of organic matter at the sea floor. Knowledge of the deposition flux, cycling rate and burial rate of biogenic elements in sediments is required to assess the influence of ocean processes on global climate and to properly interpret the sedimentary record. Recent results from this project have raised questions about the dissolution of CaCO3 from sea floor sediments as a result of CO2 metabolically released in the pore water. Models of the alkalinity change in benthic flux chambers predict an alkalinity flux from the sediments, but the chamber data show little if any alkalinity flux during sea floor deployments. The goals of the present research are 1. To determine the influence of metabolically released CO2 on the dissolution of CaCO3 in deep sea sediments; 2. To determine the kinetic expression that accurately represents CaCO3 dissolution on the dea floor. The first part of the project consists of a short cruise to the continental slope off North Carolina to test a new High Pressure Sediment Sampler and some alterations to the benthic chambers by the P.I. The project is being coordinated with work on the same topic by Sayles and Martin (using a wire-line in situ whole core squeezer) and by Reimers (using PCO2 microelectrodes. The short test cruise provides an opportunity to test all the equipment and in addition may provide date on carbonate dissolution in an area where flux of organic carbon to the sea floor is predicted to be high, but bottom waters are saturated with CaCO3. The major portion of the work will be focussed on the Ceara Rise- guiana Basin region where the presence of Antarctic Bottom Water undersaturated with CaCO3 should cause significant measurable dissolution. The sea floor fluxes of carbonate system parameters measured by the in situ benthic flux chambers (this project) will be compared to the results from the other techniques.

这个项目是海底有机物循环和成岩作用研究的延续。为了评估海洋过程对全球气候的影响和正确解释沉积记录，需要了解沉积物中生物元素的沉积通量、循环速率和埋藏速率。该项目的最新结果提出了关于海底沉积物中CaCO3溶解的问题，这是由于孔隙水中代谢释放的二氧化碳造成的。底栖通量室的碱度变化模型预测了来自沉积物的碱度通量，但通量室的数据显示，在海底分布期间，即使有碱度通量，也几乎没有。本研究的目标是：1。测定深海沉积物中代谢释放CO2对CaCO3溶解的影响；2. 确定准确表征CaCO3在dea底板上溶解的动力学表达式。项目的第一部分包括到北卡罗莱纳州的大陆斜坡进行一次短途巡航，以测试一个新的高压沉积物采样器和P.I.对底栖生物室的一些改动。该项目正在与Sayles和Martin（使用钢丝绳原位全芯挤压器）和Reimers（使用PCO2微电极）在同一主题上的工作进行协调。短期测试巡航提供了一个测试所有设备的机会，此外还可以提供一个区域的碳酸盐溶解的日期，该区域的有机碳到海底的通量预计会很高，但底部的水被CaCO3饱和。工作的主要部分将集中在Ceara Rise- guiana盆地地区，在该地区存在着CaCO3不饱和的南极底水，应该会导致显著的可测量的溶解。由原位底栖生物通量室（本项目）测量的碳酸盐系统海底通量参数将与其他技术的结果进行比较。