The Bengal Fan is world famous for its developed turbiditic system. This study identified turbidite records in a gravity core (BoB-104) taken from near a currently inactive channel (E4) based on lithology, geochemical and mineralogical parameters. This core contained turbidite and hemipelagic layers in this core. This study identified 21 turbidite layers which exhibited consistent provenance with the hemipelagic layers, showing a two end-member mixing pattern and indicating consistent sources since the last glacial period. Typical turbidite layer analysis was used to study the possible turbidite deposition mechanism. Features such as the lithology break interface, normal graded sequence, a consistent pattern of a sharp increase and gradual decrease in the variation of the mean grain size (Mz), and median grain size (D50) and Si/Al ratios commonly implied a continuous deposition in accordance with variations in densities and particle sizes. This study identified long-term evolution of turbidite deposition in the eastern middle Bengal Fan that appears to be the last and indispensable part of the systematic response of the “Bengal depositional system” to the climate. Four stages were identified from the turbidite records and all the identified intervals showed synchronous changes with the entire system. The Indian summer monsoon (ISM) played a dominant role in the system interactions. The sea level affects the turbidity system by regulating the transition of the deposition center between the deep-sea and the shelf, whereas the migration of the main channel to the “Active Valley (AV)” between 14.5 ka to 10.4 ka almost halted the deposition of turbidites along the E4 channel. Thus, turbidity activity in the eastern middle Bengal Fan is not an isolated incident but part of a comprehensive system resuling from global and regional changes at different scales.

孟加拉扇以其发达的浊流系统而闻名于世。这项研究根据岩性、地球化学和矿物学参数，确定了取自当前非活动通道 (E4) 附近的重力岩心 (BoB-104) 中的浊积岩记录。该岩心在该岩心中包含浊积岩和半远洋层。这项研究确定了 21 个浊积岩层，它们与半远洋层显示出一致的出处，显示出两个端元混合模式，并表明自上次冰期以来的来源一致。典型的浊流层分析被用来研究可能的浊流沉积机制。岩性断裂界面、正常的分级序列、平均粒度（Mz）变化的急剧增加和逐渐减少的一致模式等特征，和中值晶粒尺寸 (D50) 和 Si/Al 比通常意味着根据密度和颗粒尺寸的变化进行连续沉积。这项研究确定了中孟加拉扇东部浊流沉积的长期演变，这似乎是“孟加拉沉积系统”对气候的系统响应的最后和不可或缺的部分。从浊积岩记录中确定了四个阶段，所有确定的间隔都显示出与整个系统的同步变化。印度夏季风（ISM）在系统相互作用中起主导作用。海平面通过调节深海和陆架之间沉积中心的转变来影响浊度系统，而主通道向“活动谷（AV）”的迁移在14.5 ka到10之间。4 ka 几乎停止了沿 E4 通道的浊流沉积。因此，中东部孟加拉扇的浊度活动不是孤立事件，而是由全球和区域不同尺度变化引起的综合系统的一部分。