新疆伊犁地区黄土的粒度特征与物质来源  

DEPOSITIONAL FEATURES AND MATERIAL SOURCES OF LOESS IN YILI REGION, XINJIANG

作　　者：叶玮[1] 靳鹤龄[2] 赵兴有[1] 陈险峰 

机构地区：[1]中科院新疆生态与地理研究所,乌鲁木齐830011 [2]中科院兰州沙漠研究所,兰州730000

出　　处：《干旱区地理》1998年第4期1-8,共8页Arid Land Geography

基　　金：国家自然科学基金!49671009

摘　　要：伊犁地区是新疆重要的黄土分布区之一。黄土的粒度分析结果表明，与东部季风区黄土类似，黄土组成中以粉砂占优势，但伊犁地区的黄土却以砂含量低，细粉砂和粘粒含量高而显著区别于黄土高原的典型黄土沉积和新疆其它地区的黄土，反映西风的远源输送在该区域黄土形成过程中扮演着重要角色，粉尘来自西部荒漠。Located in the western section of the Tianshan Mountains, China, Yili region is an intermontane basin between the northern and southern Tianshan Mountains. It is one of the maindistribution areas of loess in Xinjiangs. Many researches about loess in Xinjiang have been carried out. Compared woth that on the Leoss Plateau, however, Xinjiang still has a long way to go in both comprehensive and in－depth studied, especially in north Xinjiang mainly affected by westerly system. There are still many gapsin on loess study, such as depositional features of loess, substitute indexes of palaeoclimate, material sources of loess. The contention also exists in the loess formation causes and age as well as the depositional palaeoenvironment. Yili region is a typical climate area of westerly wind, and its loess distribution is chacterized by spatial extensiveness. In this paper, it is attempted to approach the material sources of loess in Yili region through analyzing the loess distribution patterns and granularity features and comparing the loess depositional features with that in the monson areas. The analyzed results of loess granularity show that the loess compition in Yili region is dominated by silt, with low content of sand and high content of fine silt and cay, which is similar to that in the monsoon areas in east China but obriously different from that of the typical loess deposition on the Loess Plateau and that in other regions of Xinjiang. It indicates that the long－distance transport by westerly wind played an important role in the loess deposition in Yili region and the material came from weatern deserts.

关 键 词：伊犁地区 黄土 沉积特征 粒度特征 物质来源 

分 类 号：P512.2[天文地球—地质学] P931.6