兰州“930505”特大尘暴沉积物重矿物研究  

STUDY ON THE HEAVY MINERALS IN THE DUSTFALL OF THE SEVERE DUSTSTORM NUMBERED 930505 IN LANZHOU AREA,GANSU PROVINCE

作　　者：陈国英[1] 戴雪荣[1] 张铭杰[1] 

机构地区：[1]兰州大学地质系,兰州大学地理科学系

出　　处：《中国沙漠》1995年第4期374-377,共4页Journal of Desert Research

基　　金：国家自然科学青年基金资助项目

摘　　要：本文对兰州“９３０５０５”特大尘暴沉积物进行了重矿物研究，鉴定重矿物共２７种，其中不稳定矿物３种、较稳定矿物１１种、稳定矿物６种和极稳定矿物７种。重矿物组合及含量特征指示特大尘暴沉积物主要来自中酸性花岗质侵入岩并混有变质岩的风化产物。从而可以认为尘暴物源区应在甘肃北山及其东邻沙漠地带，与特大尘暴开始“起沙成暴”的主要地区基本一致。若与兰州马兰黄土之重矿物组合特征相比，现代尘暴之物源区较之末次冰期时不同。This paper studies the heavy minerals in the dustfall of a catastrophic duststorm that tookplace on May 5, 1993 in Lanzhou Area, Gansu Province. Detailed determination under ,microscope reveals that there are totally 27 kinds of the heavy minerals, of which 3 kinds are of unstable,11kinds of less stable, 5 kinds of stable, and 8 kinds of extremely stable. According to the componentsand the conbination characteristics of heavy minerals and also the formation area of the duststorm,itsuggests that the wind-blown deposits are mainly derived from the sedentary products of neutral andacidic granolite and some sedentary products of metamorphic rocks.Clearly,the main source area of the dustfall deposits must be Beishan mountains(in Gansu)and the adjacent desert areas to the east .The source areas of the duststorm deposists differ from those of the Malan loess deposited in the lastglacial period.

关 键 词：特大尘暴 沉积物 重矿物 兰州 沙尘瀑 

分 类 号：P425.55[天文地球—大气科学及气象学]