Varve and Radiocarbon Chronology and Geochemistry of the Holocene Black Sea: Evolution of an Anoxic Basin

Varve 和全新世黑海的放射性碳年代学和地球化学：缺氧盆地的演化

• 批准号: 8711741
• 负责人: Michael Arthur
• 金额: $ 13.15万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-11-15 至 1990-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8711741&HistoricalAwards=false
• 关键词: Varve; Radiocarbon; Chronology; Geochemistry; Holocene

The Black Sea is the only extant, relatively larger ocean basin that contains a substantial volume of anaerobic deep water. The sediments deposited in deeper water over perhaps the last 5-7 Ky are sapropelic to finely laminated and calcareous. 21-day leg of the R/V Knorr in the Black Sea in 1988 will provide an examination of the geochemical record in sediments of the timing of initiation and expansion of deep water anoia. This will be accomplished by an integrated study of box cores and large diameter gravity cores from as many as 30 stations with extensive coverage of the basin deeps. Carefully collected and preserved cores will provide a varve- calibrated timescale for the late Holocene Black Sea sequence using various photographic methods, NMRI (nuclear magnetic resonance imaging), microdensitometry, radiocarbon dating. The results will be synthesized, in cooperation with other researchers, for interpretation of the imprint of anoxia on the sediment geochemical record and the changes in productivity and accumulation rates that accompanied climate and sea level changes; statistical treatment of varve records will yield patterns of quasi-cyclic variations on timescales of 1-1000 years. All such inferences are important for interpretation of ancient laminated, organic-carbon rich strata.

黑海是唯一现存的、相对较大的海洋盆地，含有大量的厌氧深水。 也许在过去的 5-7 Ky 里，沉积在更深水中的沉积物是腐泥到细层状和钙质的。 1988 年，R/V Knorr 在黑海进行了为期 21 天的航程，将对沉积物中的地球化学记录进行检查，以了解深水缺氧的起始和扩展时间。 这将通过对来自多达 30 个广泛覆盖盆地深处的箱式岩心和大直径重力岩心的综合研究来完成。 精心收集和保存的岩心将使用各种摄影方法、NMRI（核磁共振成像）、显微密度测定法、放射性碳测年法，为全新世晚期黑海序列提供经过校准的时间尺度。 将与其他研究人员合作综合结果，以解释缺氧对沉积物地球化学记录的影响以及伴随气候和海平面变化的生产力和积累率的变化；对 Varve 记录进行统计处理将产生 1-1000 年时间尺度上的准循环变化模式。 所有这些推论对于解释古代层状、富含有机碳的地层都很重要。