青藏高原东北边缘黄土磁化率各向异性揭示古风向的初步研究  

The Anisotropy of Loess Magnetic Susceptibility in The Northeastern Fringe of Qinghai-Xizang (Tibetan)Plateau as an Indicator of Palalowind Direction

作　　者：王建力[1] 方小敏[1] 张宇田 曹继秀 

机构地区：[1]兰州大学地理科学系

出　　处：《兰州大学学报（自然科学版）》1995年第4期155-159,共5页Journal of Lanzhou University(Natural Sciences)

基　　金：国家攀登计划

摘　　要：利用磁化率各向异性系统地研究了黄土沉积时的近地面风向。根据兰州、临夏、武都三个典型剖面共计１４０个风成黄土样品的磁化率各向异性的研究发现青藏高原东北边缘地区各时代黄土沉积的近地面风向是各不相同的，自早更新世中期到中更新世直至晚更新世，随着时间的推移，古风向都存在着一个明显的逆时针方向的改变。究其原因，这可能与青藏高原的隆起和局地特殊的地形效应以及环流形式的调整有关。Estimates of the palaeo-subaerial wind direction were studied systematically for the first time by using the anisotropy of loess magnetic susceptibility (AMS) measurements in the northwestern China. One hundred and fourty undisturbed oriented aeilian loess samples were collected from Lanzhou. Linxia and Wudu areas for AMS measurements, which indicates the subaerial wind directions were not the same while the loess deposited. From early Pleistocene to middle Pleistocene till late Pleistocene, the wind direction experienced an anticlockwise rotation in the studied area. We suggest this change is related to the uplift of the Tibet Plateau and adjustment of current and landform effects.

关 键 词：磁化率 各向异性 风向 青藏高原 古风向 

分 类 号：P425.1[天文地球—大气科学及气象学] P318