中文摘要：

硅藻在全球碳循环中发挥着重要的作用。“树荫种”硅藻在次表层水体中的勃发成席，并迅速埋藏成为硅藻席沉积，使人们逐渐意识到次表层生产在整个生产力及输出生产中起着重要作用。介绍了首次在低纬度西太平洋区域发现的硅藻席沉积的分布特征，硅藻席发现站位呈带状分布，大致呈北西一南东向展布，大部分散布在17．5°～20°N之间。采集到硅藻席沉积物的站住其水深在碳酸钙补偿深度（CCD）以下4837～6150m的深水区，多分布在较平坦的海底，且受风力和陆源物质输入影响相对较强的区域。该区域硅藻席的形成可能是由于末次冰期时该海区有大洋锋面的形成所致。该区域的成席硅藻Ethmodiscus rex（wallich）Hendey为典型的“树荫种”硅藻，可以通过自身调节浮力的作用，在水体相对稳定的贫氧大洋中生存并勃发成席。末次冰期低纬度西太平洋硅藻席沉积的发生，可能使该区成为CO2的汇。

英文摘要：

Diatom plays a significant role in the carbon cycle of the whole world. Thriving to mats in the subsuface water, the ＂shade flora＂ is buried rapidly and becomes diatom mat deposits. The subsuface diatom production plays a considerable role in the whole productivity and output productivity. The distribution of diatom mat deposits discovered in the west low-latitude Pacific Ocean is introduced in this paper. Diatom mats are in banded distribution,spreading in NW-SE direction and most distributed in deep water areas, between 17.5°-20° N and with water depth of 4 837-6 150 m below CCD,where strong wind and land material input occur. The formation of diatom mats in this area may be due to the formation of ocean front in the last glacial period. The diatom Ethrnodiscus rex （Wallich） Hendey in this area is a typical ＂shade flora＂ diatom, which can live and thrive in the oligotrophic open ocean by their regulating and floatation abilities. The occurrence of diatom mat deposits in the west low-latitude Pacific Ocean in the last glacial period makes this area become the sink of CO2 probably.