西菲律宾海现代风尘物质组成特征及其物源指示意义

Composition Characteristics and Provenance Implication of Modern Dust in the

为识别西菲律宾海现代风尘物质的具体来源及其携带动力,本次研究于2015年冬季对西菲律宾海上空风尘进行了采集,并系统分析了碎屑态组分的矿物组成和常、微量元素组合特征.西菲律宾海现代风尘沉积物中碎屑矿物成分主要有石英、伊利石、斜长石和石膏等,矿物形态均呈次棱角状,具有明显的风成沉积特征.所研究样品的Al2O3-TiO2投影主要与鄂尔多斯沙漠和巴丹吉林沙漠物质相似,而其微量元素Zr-Th-Sc组成则表现为鄂尔多斯沙漠和塔克拉玛干沙漠物质的两端元混合,说明鄂尔多斯沙漠是西菲律宾海现代风尘的主要源区,而塔克拉玛干沙漠和巴丹吉林沙漠的风尘输入对该区的影响较小.后向轨迹分析表明,西菲律宾海冬季的风尘携带动力主要是东亚冬季风.

To discriminate the provenances and the transport mechanism of modern eolian sediments in the West Philippine Sea,mineral compositions as well as major and trace elements in the detrital phase of modern dust samples collected from the sea in the winter of 2015 were analyzed.Quartz,illite,plagioclase and gypsum are the most common detrital minerals,which are subangular and show obvious characteristics of aeolian deposits.The samples in our study show similar characteristics with the eolian dust from the Ordos Desert and the Badain Jaran Desert in the TiO2 versus Al2O3 diagram.Furthermore,the Zr-Th-Sc compositions of our samples display a binary mixing of the sediments from the Ordos Desert and the Taklimakan Desert.These results indicate that the Ordos Desert is the dominant source of the modern dust input to the Philippine Sea,whereas the contributions of the Taklimakan Desert and the Badain Jaran Desert are relatively small.In terms of the backward trajectory analysis,the modern eolian dust in the Philippine Sea is dominantly transported by the Eastern Asian Winter Monsoon.