南极半岛东北部海域碎屑矿物特征与物源分析

基于南极半岛东北部海域15个表层碎屑沉积物样品和1个柱状样的碎屑矿物学分析,对该区的沉积环境与物质来源进行了相关分析。结果显示,该区碎屑矿物共有31种,其中,重矿物19种,以石榴子石、紫苏辉石、绿帘石、普通角闪石为主;轻矿物12种,以石英、斜长石、火山玻璃(褐色、无色)为主。根据矿物组合分布特征,研究区可以划分为2个碎屑物沉积区:Ⅰ区为辉石-磁铁矿-火山玻璃型,主要物质来源为南设得兰群岛及南极半岛北段火山岩与火山喷发物,冰川为其主要搬运介质和动力来源;Ⅱ区为石榴子石-绿帘石-角闪石-石英型,南奥克尼群岛物质、南极绕极环流搬运南极半岛及其附近岛屿的物质对该区沉积物均有贡献。

CHARACTERISTIC AND PROVENANCE OF CLASTIC MINERALS IN SURFACE SEDIMENTS IN THE WATERS NORTHEAST OF THE ANTARCTIC PENINSULA

Based on the mineralogical analysis of 15 surface sediment samples and a core sample obtained on the northeastern off Antarctic Peninsula，the depositional environment and sediment provenance were studied. As revealed by this study 31 kinds of mineral were recognized，including 19 species of heavy mineral and 12 species of light mineral. Garnet，hypersthenes，amphibole，epidote are dominated heavy mineral，and quartz，plagioclase，volcanic glass (brown and white ) are main species of light mineral. According to the distribution of mineral assemblages，two minerral provinces could be identified，namely province I that is pyroxene - magnetite - volcanic glass type and province II of garnet- epidote - amphibole - quartz type. Volcanic rock and volcanic eruptions of the South Shetland Islands and the northern of the Antarctic Peninsula， transported by glacial process，are the main source of province I. Meanwhile，detrital materials from local area of South Orkney Islands and Antarctic Peninsula and adjacent islands carried by the Antarctic circumpolar circulation are the predominated source of province II.