摘要
利用同位素实验室ICP-OES,分析杉木河流域内的19个岩石样品的Ca2+,Mg2+等元素特征,结合研究区喀斯特峡谷形态类型及分布特征,分析岩石地球化学特征对喀斯特峡谷形态与分布的影响,结果发现:研究区不同地层的地球化学特征大概分为3种类型.杉木河上游各支流河段以单循环谷为主,以灰质白云岩为主的高台组∈2g,发育喀斯特V型谷;以石灰岩、白云质石灰岩为主的炉山组∈3l和清虚洞组∈1q,发育喀斯特箱型谷.杉木河主河道中下游以喀斯特双循环谷为主,喀斯特峡谷套箱型谷(上部V形谷套下部箱型谷)发育在上部灰质白云岩、下部白云质灰岩地层,喀斯特峡谷套嶂谷发育在上部灰质白云岩、下部砂岩河段.由此可知,发育不同峡谷类型的地层,具有不同的岩石地球化学特征,喀斯特双循环谷上下不同峡谷形态,取决于上下岩层的岩石地球化学特征性质.
As one of the most important factors affecting landform development, lithology always plays an important role in landscape evolution. By analyzing the indexes, such as Ca2＋ and Mg2＋ , of 19 rock samples in the Shamu Drainage Basin by ICP-OES in Geochemistry and Isotope Laboratory of Southwest University, and combining them with the characteristics of the main landscapes distributed in the research area, the influences of geochemical characteristics on the forms and distribution of karst gorges are analyzed in this paper. The geochemical features of different formations in the research area are classified into three major types. Lithology affects landscape evolution slightly because in spite of the differences of lithology from watershed to valley, the landscapes do not change simultaneously but manifest reversal serial from peak cluster-valley to peak cluster-depression to peak cluster-gorge. Lithology has a great influence on gorge form in the same development stage. Analysis of four kinds of gorge formations in the research area shows that in the sections of the tributaries of the upper reaches of the Shamu River, single cycle-process gorges are mainly distributed, of which V-shaped valleys are mainly in the dolomite lithology layer ∈2g, box-shaped valleys are mainly in the limestone lithology layers ∈ 3l and ∈ 1q; and double-cycle-process gorges are mainly distributed in the middle and lower reaches of the Shamu River, including V-shaped gorges up and box-shaped gorges down （karst gorges up and box-shaped gorges down） and karst gorges up and box shaped gorges down.
出处
《西南大学学报（自然科学版）》
CAS
CSCD
北大核心
2012年第6期114-120,共7页
Journal of Southwest University(Natural Science Edition)
基金
国家自然科学基金资助项目(41001367)
贵州省科学技术基金资助项目(黔科合J字[2009]2036号)
西南大学博士基金资助项目(SWUB2008060)
