• 作者： 陳民本
• 作者服務機構： 國立臺灣大學海洋研究所
• 中文摘要： 從南中國海所採之七十八根活塞岩心的頂部來研究表面沉積物中組織的特性及其成份。從地形和海水深度兩方面可將 南中國海分成三部份，即大陸棚帶、礁灘複合帶以及深海平原帶。礁灘複合帶包括西沙、中沙和南沙諸?島和珊瑚礁，他 們主要位於水深介於二百公尺及二千公尺之間。南中國海的深海平原水深在四千公尺以上。沙質的陸源沉積在孫達陸棚上之含量超過百分之四十。在中沙?島及南沙?島東部之粗粒沉積中，主要含有孔蟲和翼足類。在深海平原上及南沙?島的 東部沙粒物質僅含不到百分之五，但黏土部份可達百分之五十。在婆羅乃海槽內之黏土含量可達百分之八十。碳酸鹽的補 償層約與四千公尺的等深線相合，也就是說深海平原的碳酸鹽含量不到百分之十，因?中沙?島及南沙?島之東部富含有孔蟲，因此該地之碳酸鹽含量可達百分之九十以上。 一般言之，南中國海大陸棚上之碳酸鹽含量介於百分之二十與百分之 四十之間，放射蟲是深海平原上主要生物遺骸。
• 英文摘要： --
• 中文關鍵字： --
• 英文關鍵字： Seventy eight piston core tops have been analyzed in order to understand the textural characteristics of the sediments from the South China Sea. According to the topography and sea water depth, the South China Sea can be divided into three parts; continental shelf, bank-shoal complex and abyssal plain. The bank-shoal complex contains the Paracels Islands, the Macclesfield Banks and the Nan-Sha Islands. These three bank-shoal complexes are of depths located between 200 m and 2000 m. The water depth of the South China Sea Abyssal Plain is below 4000 m. Terrigenous sandy detritals are above 40% on the Sunda Shelf. The coarse fractions ( > 63 μm) in the Macclesfield Banks and the eastern Nan-Sha Islands mainly consist of planktonic foraminifers and pteropods. The sandy materials in the South China Sea Abyssal Plain and the eastern Nan-Sha Islands are below 5%, but the clayey materials are above 50%, whereas in the Borneo Trough, the clay content may reach 80%. The carbonate compensation depth almost coincides with the 4000-meter contour. In other words, the carbonate contents in the South China Sea Abyssal Plain are not over 10%. Because of the existence of abundant planktonic foraminifers at Macclesfield Banks and at eastern Nan-Sha Islands, the carbonate content in these area may be beyond 90%. In general, on the South China Sea continental shelf, the carbonate contents are between 20% and 40%. Radiolaria is the only abundant organism on the abyssal plain.