REU: Deep Water Carbonate Sedimentation in the Lesser Antilles Arc, Eastern Caribbean

REU：东加勒比小安的列斯群岛弧的深水碳酸盐沉积

• 批准号: 8818753
• 负责人: R. Reid
• 金额: $ 20.06万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-01-15 至 1992-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8818753&HistoricalAwards=false
• 关键词: REU; Deep; Water; Carbonate; Sedimentation

The proposed research will identify patterns, processes and controls of deep-water carbonate sedimentation in the Lesser Antilles arc. The study will be based on analysis of Holocene to late Pleistocene sediments in existing piston and gravity cores. The following questions will be addressed: 1. what are the sources and transport mechanisms of deep-water carbonate sediments in the arc?, 2. do the deep-water sediments record cyclic variations in carbonate content, carbonate mineralogy, and frequency of turbidites that correspond to sea level fluctuations?, and 3. how is carbonate sedimentation affected by arc volcanism and input of terrigenous detritus form South American sources? A stratigraphic framework for the cores will be developed using foraminiferal biostratigraphy, tephrochronology, and oxygen isotope stratigraphy. Detailed core descriptions, total carbonate analyses, thin section petrography, scanning electron microscopy, x-ray diffraction, and strontium determinations will establish the distribution of carbonate, the relative contributions of pelagic and neritic carbonate components, and the proportions of volcanic and terrigenous detritus. The study represents the first in-depth analysis of modern deep-water carbonate sediments in a convergent margin. It will complement previous studies of volcanogenic and terrigenous sediments in the Lesser Antilles to show how deep-water deposition in a volcanic arc compares with periplatform sedimentation in passive margin settings. The findings will aid interpretation of other volcanic arc sequences, both modern ancient.

拟议的研究将确定小安的列斯岛弧深水碳酸盐沉积的模式、过程和控制。这项研究将基于对现有活塞和重力岩心中全新世至晚更新世沉积的分析。将讨论以下问题：1.弧内深水碳酸盐沉积物的来源和输运机制是什么？2.深水沉积物中的碳酸盐含量、碳酸盐矿物学和浊积岩频率是否记录了与海平面波动相对应的周期性变化？弧火山作用和南美陆源碎屑的输入对碳酸盐沉积有何影响？将利用有孔虫生物地层学、年代学和氧同位素地层学建立岩心的地层格架。详细的岩心描述、总碳酸盐分析、薄片岩石学、扫描电子显微镜、X射线衍射和锶测定将确定碳酸盐的分布，远洋和浅海碳酸盐组分的相对贡献，以及火山和陆源碎屑的比例。这项研究是对汇聚边缘现代深水碳酸盐沉积的首次深入分析。它将补充先前对小安的列斯群岛火山成因和陆源沉积的研究，以显示火山弧中的深水沉积与被动边缘环境中的台地周围沉积相比如何。这些发现将有助于解释其他火山弧序列，无论是现代的古代。