普里兹湾陆架表层沉积物粒度特征及其环境指示意义

基于对普里兹湾陆架表层沉积物粒度分析,结合海区动力环境特点,初步探讨了考察区类型、组成及冰海沉积作用特点。研究区表层沉积物大体可分为:砾(G)、泥质砂质砾(ms G)、砾质泥(g M)、砾质泥质砂(gm S)、含砾泥((g)M)、含砾泥质砂((g)m S)、砂(S)、砂质粉砂(s Z)和粉砂(Z)九种类型。依据沉积物粒度特征与地形变化,可将研究区划分为东部含砾泥质区和西部含砾砂质区。在东部含砾泥质区,包括四夫人浅滩、Svenner水道区、普里兹水道区和埃默里海盆区,沉积作用主要受海流影响,冰筏碎屑的影响有限,沉积物总体较细,粘土和细粉砂含量较高,粗粉砂和砂含量较低。在西部含砾砂质区,包括弗拉姆浅滩和埃默里冰架前缘,沉积作用受冰山、埃默里冰架和海流的共同影响,沉积物中粘土含量较低,砂和砾石含量较高,但也有个别站位可能受冰间湖的影响,沉积物粒度偏细。

CHARACTERISTICS OF GRAIN SIZE IN SURFACE SEDIMENTS FROM THE CONTINENTAL SHELF,PRYDZ BAY,AND IMPLICATIONS FOR SEDIMENTARY ENVIRONMENT

Through analyzing the grain size characteristic of continental shelf surface sediments obtained during Chinese 24th and 29th South Pole Exploration in Prydz Bay，Southern Ocean to discuss the main factors influence sedimentation. The surface sediments are divided into nine types: G, msG, gM, gmS, (g)M, (g)mS, S, sZ, Z. The study area can be divided into two sections by sediment types and topography of the bay: gravelly mud section in east and gravelly sand section in west. In the eastern gravelly mud section, coastal current dominates sedimentation processes in Four Ladies Bank and Svenner Channel. In Prydz Channel and Amery Basin, Prydz Bay Gyre is the dominant factor controlling sedimentary processes. In contrast, icebergs are the primary factors influence sedimentation in front of Amery Ice Shelf and Fram Bank, while the influencing of current is weak.