Reconstructing the evolution of the Bengal Fan with physical properties (ReconFan)

用物理特性重建孟加拉扇的演化过程（ReconFan）

• 批准号: 320203302
• 负责人: Privatdozent Dr. Michael E. Weber
• 金额: --
• 依托单位: Institut für Geowissenschaften
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/320203302?language=en
• 关键词: Reconstructing; evolution; Bengal; Fan; physical

The Project ReconFan relies on my previous work and publications on different environments of the Bengal Fan and the resulting gaps in knowledge. The focus lies on sediment physical and optical property data collected during IODP Expedition 354. General objectives are to (i) unravel the history of turbiditic and hemipelagic deposition on the lower fan as a result of the interplay of Himalayan erosion and Asian monsoon development, (ii) provide high-resolution age control through orbital tuning, biomagnetostratigraphy, and ash identification, and (iii) study the response to climate and monsoon forcing on different time scales. These objectives have partially been fulfilled with the current funding, and three manuscripts have been compiled: one of which is under review, the second one is ready for submission, and the third one is near completion. During the renewal period, ongoing investigations shall be concluded and new, so far not used methods shall be employed. At least two more papers as first author shall be published. For the Pleistocene sections, age models based on orbital tuning and spectral analysis were constructed for all Expedition 354 sites, with the aid of paleomagnetic and biostratigraphic constraints. Also, Fourier Transform Infrared Spectroscopy has been used to determine bulk geochemistry. Both of these methods shall now be expanded to Plio-Miocene sections. Specifically, sediment physical (wet-bulk density, compressional-wave velocity, and magnetic susceptibility) and optical (LaCie L*, a*, b* reflectance color) properties shall be processed to assign sediment facies, i. e. determine, through geochemical calibration, the relative proportions of the three major sediment components detritus, biogenic opal, and biogenic carbonate. A novel color reflectance method, the so-called Q4/7 analysis shall be employed to test if facies variations can be discriminated based on geochemical properties. Relative proportions of sand, silt, and clay shall be determined for the detrital fraction, based on grain-size determinations, to provide highly-resolved sediment budgets for turbidites. The ultimate goals of the investigations are to obtain vital information to unravel the erosional history and the associated amount of fluvial transport via the Ganges Brahmaputra river systems, the depocenter migration with respect to sea-level changes, and the long-term changes in monsoon and climate as documented on the Lower Bengal Fan.

ReconFan项目依赖于我以前关于孟加拉扇不同环境的工作和出版物以及由此产生的知识差距。重点在于IODP第354次考察期间收集的沉积物物理和光学特性数据。总体目标是：（一）揭示由于喜马拉雅侵蚀和亚洲季风发展的相互作用而导致的下扇浊流和半远洋沉积的历史;（二）通过轨道调整、生物磁性地层学和火山灰鉴定提供高分辨率的年龄控制;以及（三）研究不同时间尺度上对气候和季风强迫的响应。这些目标在现有资金的支持下已部分实现，并已汇编了三份手稿：其中一份正在审查中，第二份准备提交，第三份即将完成。在延长期内，应结束正在进行的调查，并采用迄今为止尚未使用的新方法。以第一作者身份发表论文不少于2篇。对于更新世的部分，年龄模型的基础上轨道调谐和光谱分析的所有远征354网站，与古地磁和生物地层学的限制。此外，傅里叶变换红外光谱已被用于确定散装地球化学。这两种方法现在都应扩展到上新世-中新世剖面。具体而言，应处理沉积物物理（湿体积密度、压缩波速度和磁化率）和光学（LaCie L*、a*、B* 反射颜色）特性，以确定沉积物相，即：e.通过地球化学标定，确定沉积物中碎屑、生物蛋白石和生物碳酸盐三大主要成分的相对比例。应采用一种新的颜色反射率方法，即所谓的Q4/7分析，以测试是否可以根据地球化学性质区分相变化。应根据粒度测定结果确定碎屑部分的砂、粉砂和粘土的相对比例，以提供浊积岩的高分辨率沉积物预算。调查的最终目标是获得重要的信息，以解开侵蚀的历史和相关的量的河流运输通过恒河雅鲁藏布江河流系统，沉积中心迁移相对于海平面的变化，并在季风和气候的长期变化记录在下孟加拉扇。

项目成果

Middle to Late Pleistocene Evolution of the Bengal Fan: Integrating Core and Seismic Observations for Chronostratigraphic Modeling of the IODP Expedition 354 8° North Transect

• DOI: 10.1029/2019gc008878
• 发表时间: 2020-04
• 期刊: Geochemistry
• 影响因子: 3.7
• 作者: B. Reilly;F. Bergmann;M. Weber;J. Stoner;P. Selkin;L. Meynadier;T. Schwenk;V. Spiess;C. France‐Lanord

Hemipelagic and turbiditic deposits constrain lower Bengal Fan depositional history through Pleistocene climate, monsoon, and sea level transitions

• DOI: 10.1016/j.quascirev.2018.09.027
• 发表时间: 2018-11
• 期刊: Quaternary Science Reviews
• 影响因子: 4
• 作者: M. Weber;B. Reilly