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High resolution oxygen isotope stratigraphy of Integrated Ocean Drilling Program sites U1394, U1395 and U1396, off-shore Montserrat, Lesser Antilles

小安的列斯群岛蒙特塞拉特近海综合海洋钻探计划地点 U1394、U1395 和 U1396 的高分辨率氧同位素地层学

基本信息

批准号：
NE/K002724/1
负责人：
Christopher Smart
金额：
$ 6.05万
依托单位：
Plymouth University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2013
资助国家：
英国
起止时间：
2013 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FK002724%2F1
关键词：
resolution oxygen isotope stratigraphy Integrated

项目摘要

Our proposed research is based on cores collected during the recent, and very successful, Integrated Ocean Drilling Program (IODP) Expedition 340. The aims of this expedition were to investigate the volcanism and landslide history of the Lesser Antilles volcanic arc, by collecting a number of cores offshore Montserrat and Martinique. As a shipboard planktic foraminifera (single celled calcareous plankton) biostratigrapher (dating sediment cores using the appearances and disappearances of fossil plankton), Deborah Wall-Palmer (proposed PDRA) has access to these cores during the one year moratorium period. Until IODP Exp. 340, the longest continuous record (~250,000 years) of volcanic activity on Montserrat was a 5.75 m core collected to the south-west of the island in 2002, CAR-MON 2. This core revealed a more extensive and complete record of volcanic activity than that available in terrestrial cores. The longest continuous sediment record collected during Exp. 340 extends this record considerably. At 139.4 m in length, Hole U1396C records events back to 4.5 million years ago. The majority of this Hole will undergo stratigraphic analysis at low resolution, which will be carried out by other Exp. 340 scientists (Andrew Fraass, Mohammed Aljahdali). The upper 7 m section of this Hole is estimated to span 300,000 years and is comparable to the time period recovered in sediments for Holes U1394A/B (0 to 125 cm) and U1395B (0 to 30 cm). Holes U1394A/B and U1395B were collected close to Montserrat, in the main path of eruptive material from the Soufriere Hills volcano and contain a high resolution, but interrupted record of volcanic eruptions and landslides. Our proposed research is to provide a high resolution (every 2000 yrs) age framework across the upper ~300,000 year sections of these three cores. This will be achieved by collecting specimens of the planktic foraminifera Globigerinoides ruber and analysing the stable oxygen isotope ratios contained within their calcium carbonate tests (shells). Oxygen isotope ratios provide information about the global ice volume and global climate, and the standard record can be identified world-wide. Correlation to this record can therefore be used to provide an age framework for sediments, which is more detailed than using the biostratigraphic range of species alone. Producing this age framework is essential for achieving the overall aims of Exp. 340 as it will be used, in collaboration with several other Exp. 340 scientists, to reconstruct the volcanic and landslide history of Montserrat. In addition to this, to ensure the conservative use of samples, some further work will be carried out on samples requested from the upper 7 m of Hole U1396C. This will assist in constructing the low resolution stable isotope and biostratigraphic framework for the remainder of this Hole. The majority of this work is being carried out by Andrew Fraass (University of Massachusetts) and Mohammed Aljahdali (Florida State University). We will analyse the upper 7 m of Hole U1396C, at low resolution, for stable oxygen isotopes of the benthic foraminifera Cibicidoides spp. and for planktic foraminifera datum species.

我们提出的研究是基于最近非常成功的综合海洋钻探计划（IODP）远征340收集的岩心。这次考察的目的是通过收集蒙特塞拉特岛和马提尼克岛近海的一些岩心，调查小安的列斯火山弧的火山作用和滑坡历史。作为一名船上浮游有孔虫（单细胞钙质浮游生物）生物地层学家（利用浮游生物化石的出现和消失来确定沉积物岩心的年代），Deborah Wall-Palmer（提议的PDRA）可以在一年的暂停期内访问这些岩心。在IODP Exp. 340之前，蒙特塞拉特火山活动的最长连续记录（~25万年）是2002年在该岛西南部收集的5.75米的岩心CAR-MON 2。该岩心揭示了比陆地岩心更广泛和完整的火山活动记录。实验340期间收集的最长连续沉积物记录大大延长了这一记录。U1396C洞长139.4米，记录了450万年前的事件。这个洞的大部分将进行低分辨率地层分析，这将由其他Exp. 340科学家（Andrew Fraass, Mohammed Aljahdali）进行。据估计，该孔上部7 m段的时间跨度为30万年，与U1394A/B孔（0 ~ 125 cm）和U1395B孔（0 ~ 30 cm）沉积物中恢复的时间相当。U1394A/B和U1395B洞是在Montserrat附近收集的，位于Soufriere Hills火山喷发物质的主要路径上，包含高分辨率，但火山喷发和山体滑坡的中断记录。我们建议的研究是在这三个岩心的上~30万年剖面上提供一个高分辨率（每2000年）的年龄框架。这将通过收集浮游有孔虫Globigerinoides橡胶的标本和分析其碳酸钙测试（壳）中包含的稳定氧同位素比率来实现。氧同位素比值提供了关于全球冰量和全球气候的信息，并且可以在世界范围内确定标准记录。因此，与这一记录的相关性可以用来提供沉积物的年龄框架，这比单独使用物种的生物地层范围更详细。制作这个年龄框架对于实现Exp. 340的总体目标至关重要，因为它将与其他几位Exp. 340科学家合作，用来重建蒙特塞拉特的火山和滑坡历史。除此之外，为了保证样品的保守使用，将对U1396C孔上部7m要求的样品进行进一步的工作。这将有助于为该孔的其余部分构建低分辨率稳定同位素和生物地层格架。这项工作的大部分由Andrew Fraass（马萨诸塞大学）和Mohammed Aljahdali（佛罗里达州立大学）完成。我们将以低分辨率分析U1396C洞上部7 m的底栖有孔虫Cibicidoides sp.和浮游有孔虫基准物种的稳定氧同位素。