毛乌素沙地现代流动沙丘沙的矿物成分

doi:10.7522/j.issn.1000-694X.2014.00006

摘要/Abstract

摘要：

对毛乌素沙地16个现代流动沙丘沙样品矿物分析结果进行归纳与研究.结果显示:(1)毛乌素沙地现代流动沙丘沙轻矿物占绝对优势,平均含量为94.8%,以石英、长石为主;重矿物所占比例很小,平均含量为1.6%,但种类较多,共含22种重矿物.(2)重矿物中2/3以上属硅酸盐类矿物,其含量前三的为角闪石、绿帘石、石榴子石;(3)重矿物以不稳定矿物和较稳定矿物占较高比例,绝大多数为硅酸盐类矿物,分别为100%和98.75%;(4)重矿物中硬矿物和极硬矿物含量高达80.17%,分别为61.57%和18.60%.结果还显示,轻矿物石英/长石含量比值(平均值为6.10)和重矿物矿物风化系数(平均值3.89)都较高,重矿物中造岩矿物(平均值26.7%)含量占近1/3.由此,并考虑到高含量的硬-极硬的重矿物的存在,表明其沉积时属于气候干冷、生物化学风化作用较弱的强风沙流环境.本文除证明了高含量的不稳定矿物和较稳定矿物与气候干旱具有本质上的联系外,还说明了干旱环境下沙丘沙中多种类、高含量的硬-极硬矿物的存在,极大地抑制了物理风化和生物化学两个方面的风化的难度,从而使其向土壤化根本逆转也很难.即使沙丘得以固定,由于其丘体的这种矿物组分,仍然难以消除潜在沙漠化的客观存在,故土地沙漠化引起生态环境的退化实际上也与沙丘沙碎屑矿物的物理性质具有本质上的联系.因此,干冷多风的气候条件及其导致的沙丘沙所具有的物质组成的特殊性应该是土地沙漠化的两个不可或缺的原因.

关键词: 毛乌素沙地, 现代流动沙丘沙, 碎屑矿物, 干旱环境

Abstract:

Mineral composition of 16 modern mobile sand dunes sand particle samples from Mu Us Sandy Land was analyzed. Results show that: (1) Light minerals dominate in content, with 94.8% on average and the principal compositions are quartz and feldspar; In these samples little heavy minerals exist, with average 1.6%, but number of mineral species is various, with about 22 kinds. (2) More than 2/3 of heavy minerals are silicate minerals, and the TOP 3 are amphibole, epidote and garnet in content. (3) Unstable minerals and relatively stable minerals account for a big proportion in heavy minerals. In this two kinds of mineral assemblages, silicate minerals occupy absolute advantage, respectively 100% and 98.75%. (4) Hard minerals and ultrahard minerals in heavy minerals totally reach up to 80.17%, respectively 61.57% and 18.60%. The results also show high Q/TF ratio (average 6.10) in light minerals and high HW value (average 3.89) in heavy minerals. Rock-forming minerals (average 26.7%) account for nearly 1/3 in heavy minerals. Therefore, given the high content of hard and ultrahard heavy minerals, all these indicate that the dune sand particles was deposited in the dry-cold climate with strong wind-sand flow environment and weak biological and chemical weathering. The discussion of this paper on mineral components of sans particles of modern mobile sand dunes in Mu Us Sandy Land not only proves the essential relationship between the arid climate and the high content of unstable minerals and relatively stable minerals, but also shows the existence of various kinds and high content of hard and ultrahard minerals greatly inhibits both physical weathering and biochemical weathering and makes it difficult to reverse to pedogenesis fundamentally. Even though the dunes can be fixed, it is still difficult to eliminate the objective existence of potential desertification because of such mineral components of the dunes, so the degeneration of ecological environment resulted from desertification has essential relationship with the physical properties of clastic minerals in dune sand. Therefore, the dry-cold and windy climate conditions and its resulted special material composition in dune sand are the two essential causes of land desertification.

Key words: Mu Us Sandy Land, sand particles of modern mobile sand dunes, clastic minerals, arid environment

中图分类号:

P575

胡观冠, 李保生, 温小浩, 牛东风, 郭亿华, 郭元军, 司月君, 舒培仙. 毛乌素沙地现代流动沙丘沙的矿物成分[J]. 中国沙漠, 2014, 34(6): 1454-1460.

Hu Guanguan, Li Baosheng, Wen Xiaohao, Niu Dongfeng, Guo Yihua, Guo Yuanjun, Si Yuejun, Shu Peixian. Mineral Composition of Sand Particles of Modern Mobile Sand Dunes in the Mu Us Sandy Land[J]. JOURNAL OF DESERT RESEARCH, 2014, 34(6): 1454-1460.

参考文献

[1] 严钦尚.陕北榆林定边间流动沙丘及其改造[J].科学通报,1954,(11):28-34.
[2] 朱震达,刘恕,邸醒民.中国的沙漠及其治理[M].北京:科学出版社,1989:1-126.
[3] 陈育宁.鄂尔多斯地区沙漠化的形成和发展述论[J].中国社会科学,1986,(2):69-82.
[4] 朱震达,刘恕,侯仁之.历史时期的沙漠变迁[M]//中国自然地理(历史自然地理).北京:科学出版社,1982:249-260.
[5] 赖忠平,苗晓东,周杰,等.沙漠黄土边界带风成沙再生法单片技术等效剂量分布[J].核技术,2001,24(12):1022-1023.
[6] 赵华,卢演俦,尹金辉.科尔沁沙地全新世风沙沉积物的石英单测片蓝光释光测年和风沙活动年代学[J].核技术,2005,28(5):367-374.
[7] 覃金堂,周力平.沙漠边缘厚层黄土上部光释光测年的初步研究[J].第四纪研究,2007,27(4):546-552.
[8] 吴正.浅议我国北方地区的沙漠化问题[J].地理学报,1991,46(3):266-278.
[9] 董光荣,李保生,高尚玉,等.鄂尔多斯高原第四纪古风成沙的发现及其意义[J].科学通报,1983,16:998-1001.
[10] 董光荣,李保生,高尚玉.由萨拉乌苏河地层看晚更新世以来毛乌素沙漠的变迁[J].中国沙漠,1983,3(2):9-14.
[11] 董光荣,高尚玉,李保生,等.毛乌素沙漠的形成、演化和成因问题[J].中国科学(B辑),1988,(6):633-642.
[12] Li B S,Gao S Y,Dong G R,et al.Environmental evolution of Ordos Desert in China since 1.1Ma B.P.as indicated by Yulin stratigraphical section and its grain-size analysis results[J].Chinese Geographical Science,2005,15:34-41.
[13] 吴正,董光荣,李保生,等.从晚更新世以来我国沙漠的变迁看干旱区沙漠化问题[J].华南师范大学学报(自然科学版),1987,(2):72-77.
[14] 李保生,安芷生,祝一志,等.沙尘暴形成史初步研究——中国沙漠几个典型地质学记录的实证[J].地学前缘,2002,9(3):189-200.
[15] Li B S,Zhang D,Wen X H,et al.Multi-cycles of climatic fluctuation in the last Interglacial period[J].Acta Geologica Sinica,2005,79(3):398-404.
[16] 鹿化煜,李朗平,戈双文,等.中国北方沙漠-黄土体系的沉积和侵蚀过程与未来趋向探析[J].地学前缘,2010,17(5):336-344.
[17] 丁仲礼,孙继敏,刘东生.上新世以来毛乌素沙地阶段性扩张的黄土-红粘土沉积证据[J].科学通报,1999,44(3):324-326.
[18] 黄银洲,王乃昂,程弘毅,等.毛乌素沙地历史时期沙漠化——基于北大池湖泊周边沉积剖面粒度的研究[J].中国沙漠,2013,33(2):426-432.
[19] 花婷,王训明,次珍,等.中国干旱、半干旱区近千年来沙漠化对气候变化的响应[J].中国沙漠,2012,32(3):618-624.
[20] 黄杏珍,潘中海.应用粒度资料探讨毛乌素沙漠[J].地理学报,1981,36(1):70-78.
[21] Li B S,Wen X H,Qiu S H,et al.Phases of environmental evolution indicated by primary chemical elements and paleontological records in the Upper Pleistocene-Holocene series for the Salawusu River Valley,China[J].Acta Geologica Sinica, 2007,81(4):555-565.
[22] 王克鲁,裴静娴.山西隰县午城黄土矿物成分[M].北京:科学出版社,1964:89-110.
[23] 李保生,董光荣,高尚玉.萨拉乌苏河地区第四纪地层中的矿物成分与气候环境[M]//第四纪冰川和第四纪地质论文集(五).北京:地质出版社,1988.
[24] 李保生,董光荣,高尚玉,等.萨拉乌苏河地区地层中的碎屑矿物及其所反映的中更新世末期以来之气候环境变化[J].岩石矿物学杂志,1991,10(1):84-89.
[25] M II 彼得罗夫.鄂尔多斯、东阿拉善和黄河中游河谷的砂子的矿物成份及其成因[J].地理学报,1959,25(1):1-20.