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

我们提出的研究是基于最近收集的核心，非常成功的，综合大洋钻探计划（IODP）远征340。这次考察的目的是通过收集蒙特塞拉特和马提尼克岛近海的一些岩心，调查小安的列斯群岛火山弧的火山活动和山崩历史。作为船上的浮游有孔虫（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）在一年的暂停期内可以接触到这些岩心。直至IODP失效340年，蒙特塞拉特火山活动最长的连续记录（约250 000年）是2002年在该岛西南部收集的5.75米岩心，CAR-MON 2。该岩芯揭示了比陆地岩芯更广泛、更完整的火山活动记录。最长的连续沉积物记录收集在实验。第340章这一记录的延续U1396 C洞长139.4米，记录了450万年前的事件。该孔的大部分将进行低分辨率地层分析，这将由其他实验室进行。340名科学家（Andrew Fraass、Mohammed Aljahdali）该孔上部7米的部分估计跨越30万年，与U 1394 A/B孔（0至125厘米）和U 1395 B孔（0至30厘米）沉积物中恢复的时间段相当。U 1394 A/B和U 1395 B孔是在蒙特塞拉特附近采集的，位于苏弗里埃山火山喷发物质的主要路径上，含有高分辨率但间断的火山喷发和山崩记录。我们建议的研究是提供一个高分辨率（每2000年）的年龄框架，在这三个核心的上30万年的部分。这将通过收集南极有孔虫Globigerinoides ruber的标本并分析其碳酸钙测试（贝壳）中所含的稳定氧同位素比率来实现。氧同位素比值提供了有关全球冰量和全球气候的信息，并且标准记录可以在世界范围内识别。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。制定这一年龄框架对于实现Exp的总体目标至关重要。340，因为它将被使用，与其他几个实验室合作。340名科学家，重建蒙特塞拉特火山和滑坡的历史。除此之外，为了确保样品的保守使用，将对要求从U1396 C孔上部7 m采集的样品进行一些进一步的工作。这将有助于建立该孔剩余部分的低分辨率稳定同位素和生物地层框架。这项工作的大部分由Andrew Fraass（马萨诸塞州大学）和Mohammed Aljahdali（佛罗里达州立大学）进行。我们将在低分辨率下分析U1396 C孔上部7 m的底栖有孔虫Cibicidoides spp的稳定氧同位素。和浮游有孔虫基准种。

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.