2005-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/705018摘要：湄公河是東南亞最長的河川，亦是世界重要河川之一，其流經整個中南半島，最後從越南南部流入南海，對於南海陸源物質的來源扮演著重要的角色。故本研究之目的將藉由分析湄公河外海陸棚及陸坡沉積物中金屬鋁、鐵、錳、鋅含量及顆粒大小組成，來探討湄公河外海陸棚及陸坡地區沉積物之空間分佈變化，並進一步探討影響本研究區域金屬空間分佈變化的主要控制因子。 研究結果顯示湄公河外海陸棚地區沉積物主要由金屬含量較低的粗顆粒沉積物所組成，而僅於東方之南海陸坡海域發現有細顆粒沉積物堆積。這可能是湄公河的泥質懸浮顆粒未直接輸出至南海，而大多僅於河口三角洲沉積；或是受到季風、洋流等因素影響，細顆粒沉積物未沉積於陸棚地區，而被帶至南海陸坡或往西傳輸至暹羅灣內沉積。影響湄公河外海沉積物金屬含量分佈的控制因子為顆粒大小組成及沉積物之成岩作用。鐵、鋅金屬含量與鋁呈現明顯的正向關係，顯示沉積物鐵、鋅含量受到沉積物細顆粒鋁矽鹽黏土礦物的多寡所控制。而錳金屬含量於陸坡地區出現異常高值，這可能為沉積物成岩作用使錳金屬於沉積物表層富集所致。 <br> Abstract: Understanding terrigenous material burial in the marine environment is important in evaluating fate of terrigenous material transport to the ocean. Mekong River is an important source of terrigenous material entering the South China Sea. Very few data is currently available in evaluating fate of terrigenous from the Mekong River to the South China Sea. The purpose of this research is to investigate burial of inorganic metals associate with aluminosilicates in the shelf and slope region offshore Mekong River. Sediment grain size and metals (aluminum, iron, manganese, zinc) were determined. The results demonstrated that most suspended sediment may not reach the open shelf and slope. Coarse-grained sediments with lower metal concentrations were found in the shelf area offshore Mekong River while most fine-grained sediments were found in the slope region of the Southern South China Sea. Metals associated with aluminum silicate showed very good linear relationships with respect to the aluminum concentrations. Almost no fine-grained sediment deposited in the shelf region offshore Mekong River indicated that most fine-grained suspended particle originated from the Mekong river do not reach offshore and were deposited within the Mekong Delta, or transported further offshore to the slope region.