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新生代孟加拉湾深海扇沉积物的 TiO_2/Al_2O_3比,毫无疑问具有作为古水流流速指标的潜在可能。原因是,即便在最细的海底扇悬浮物中,水动力分选过程也决定着较重的富 TiO_2矿物相对于较轻的富 Al_2O_3粘土矿物的量。孟加拉湾及其南部的五个深海钻探计划钻孔(213—217)的岩心中,TiO_2/Al_2O_3比从晚中新世到现代与时间成比例地增加。这一增加反映了海底扇的进积以及孟加拉湾南部海底扇上底流活动的加剧。这些过程由于下述因素而与喜马拉雅山的抬升有关,如印度北部河系的成熟,地形季风雨的变化,以及山脉抬升造成的剥蚀率的上升。
The TiO 2 / Al 2 O 3 ratio of Cenozoic deep Bay fan sediments in the Bay of Bengal undoubtedly possesses the potential as an indicator of ancient flow velocity. The reason for this is that even in the finest submarine fan suspensions hydrodynamic separation processes determine the amount of heavier TiO 2 -rich minerals relative to lighter Al 2 O 3 -rich clay minerals. In cores of five deep-sea drilling programs in the Bay of Bengal and the south of it (213-217), TiO 2 / Al 2 O 3 is increased in proportion to the time from late Miocene to modern times. This increase reflects the progress of the seabed fan and the escalation of the seabed fan in the south of the Bay of Bengal. These processes are linked to the uplift of the Himalayas due to such factors as the maturation of river systems in northern India, the changes in the monsoon rains over the terrain, and the increase in the rate of erosion caused by uplift of the mountains.