古洪水事件判别以及微形态学在古洪水事件判别中的应用  

Identification Marks of Paleo-flood Events and the Preliminary Application of Micro-morphology in It

作　　者：戴小国[1] 查小春[1,2] 庞奖励[1] 

机构地区：[1]陕西师范大学旅游与环境学院,陕西西安710062 [2]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100

出　　处：《干旱区研究》2009年第3期340-346,共7页Arid Zone Research

基　　金：国家自然科学基金项目(40571154;40471119);陕西省自然科学基金项目(2006D01);黄土与第四纪地质国家重点实验室基金项目(SKLLQG0604);中国科学院黄土高原土壤侵蚀与旱地农业国家重点实验室项目(10501-176);陕西师范大学优秀科技预研项目(200702001)资助

摘　　要：古洪水研究是全球变化研究的热点问题,而研究古洪水的关键是如何有效地寻找及准确判定古洪水平流沉积。在综述古生物学、考古学、沉积学、地球化学对研究古洪水事件作用的基础上,结合微形态研究方法,对古洪水和其他层位薄片的微形态进行了对比分析,表明二者在颗粒特征、矿物组合、孔隙及微垒结等方面存在明显的区别,说明微形态能够用来研究和判别古洪水事件,为古洪水研究提出了一个新的研究思路。Paleo-flood hydrology study is a hot field in global change study. It is the key for studying paleo-flood events how to look for and identify the paleo-flood slack-water deposits effectively and accurately. In this paper, the effects of paleontology, archeology, sedimentology and geochemistry in studying paleo-flood events are summarized at first, and then the micro-morphological features of paleo-flood deposits and other strata are compared and analyzed based on the theory of micro-morphology. The results show that the grain characteristics, mineral composition, pores and micro-configuration in paleo-flood deposits are obviously different from those in other strata： （1） The grains in the paleo-flood slack-water deposits are fine, well-sorted and subrounded or rounded; （2） Mineral composition in the paleo-flood deposits is similar to that in other strata, but the contents of unstable minerals are relatively low in paleo-flood deposits; （3） Soil in paleo-flood deposits is dominated by clay, and the clay content is second only to that in paleosol; （4） The pores are irregular, and the pore walls are coarse. These reveal that the micro-morphology can be used to research and identify the paleo-flood events.

关 键 词：古洪水 判别标志 微形态学 全球变化 平流沉积 

分 类 号：P531[天文地球—古生物学与地层学]