南海中北部表层沉积物的矿物沉积

Mineral sedimentation in the surface sediment of northern and central South China Sea

本文研究了南海中北部500多个样品的矿物学。认为,本区表层沉积物中矿物种类繁多,分布较为普遍,碎屑矿物(含火山物质)、粘土矿物、自生矿物常有出现。以前者为最显著(共60多种,其中重矿物50多种,轻矿物近10种),主要分布于陆架区及深海盆;粘土矿物次之,多分布于陆坡～深海盆;自生矿物较少,陆架～深海盆均有分布。文中根据矿物沉积特征和环境差异,把它划分为6个矿物区。

The paper studies mineralogy of more than 500 samples from waters north to 12°N in the South China Sea. Many species of we suggest sedimentary minerals are widely distributed with clastic mineral (including volcanic matters),clay minerals, authigenic minerals the common ones. Clastic minerals are the most abundant, distributing mainly in the continental shelf and deep sea basin; clay minerals come the second, distributing in the continental slope～deep sea basin; authigenic minerals the third, distributing in the continental shelf～deep sea basin.There are altogether over 60 species of terrigenous clastic minerals types, more 50 heavy minerals and about 10 light minerals. The minerals are dominated by silicate and oxide, followed by carbonate and phosphote and then others. Volcanic matters consist of volcanic glass, volcanic clastic mineral, volcanic dust,volcanic silt ball and so on; clay minerals consist of Kaolinite Illite, Chlorite, Montmorillonite and mixed-layered clay minerals; authigenic minerals consist of Mn nodules, glauconite, pyrite, collophane and zeolite.Based on different sedimentary features and environments, six mineral zones may be classified: I . Ilmenite-Zircon-Chlorite-Mica zone; Ⅱ . Zircon-Ilmenite-Quartz zone; Ⅲ. Limonite-Zircon-Ilmenite-Quartz zone;Ⅳ. Zircon-Ilmenite-Epidote-Quartz zone; V . Quartz containing few volcanic matters-Feldspar-Clay mineral zone; Ⅵ. Clay mineral containing few volcanic matters zone.