Geochemical Composition and Weathering Feature of Surface Sediment in the Dumeng Sandy Land, Northeast China
Received date: 2012-04-20
Revised date: 2012-05-21
Online published: 2012-05-21
The surface sediment samples from Dumeng sandy land were collected and divided into different grain size fractions (bulk sample, >63 μm, 63-30 μm, 30-11 μm and <11 μm ). These samples were analyzed in the laboratory to obtain composition of geochemical elements. The result shows that Si and Al take up a large part of chemical composition of surface sediment in Dumeng sandy land. Compared with the average composition of geochemical elements in the upper continental crust (UCC), Fe, Mg and Ca are depleted to a severe degree, Al and Na are depleted to a medium degree, and K are depleted slightly; Fe, Mg, Ca, P, Ti and Mn contents have high coefficients of variation; The variation degrees of major elements in different grain size fractions increase in the following order: Al<Si<Na<K<P<Fe<Ti<(Ca, Mn)<Mg, and variation of Al element is relatively slight. The volumes of Fe, Mg, Ca, Mn, Ti and P elements gradually increase with decreasing grain size, while the volumes of Si, Na and K are exactly the opposite, and the relationship between Al element and grain size is not significant. The influence of grain size on chemical weathering index is ranked in the following order: CIA<(Al+Fe+Ti+Mn)/(Mg+Ca+K+Na)<(CaO+K2O+Na2O)/Al2O3<Fe2O3/MgO<K2O/Al2O3<(CaO+MgO+Na2O)/TiO2. CIA is the best index reflecting chemical weathering degree, and next are (Al+Fe+Ti+Mn)/(Mg+Ca+K+Na) and (CaO+K2O+Na2O)/Al2O3, followed by Fe2O3/MgO and K2O/Al2O3, and (CaO+MgO+Na2O)/TiO2 ratio is greatly influenced by grain size, so it isnt a good index of chemical weathering degree of sediments. The CIA value of Dumeng sandy land is 52.28, A-CN-K ternary diagram shows that these sediments are in the early stage of continental chemical weathering characterized by slight loss of Na and K, and other geochemical elements are in a less weathering or leaching process. A-CNK-FM ternary diagram suggests that Fe and Mg only have undergone slight chemical differentiation because of weak physical weathering and chemical weathering under the condition of semi-arid and semi-humid climatic. In addition, short transport distance of sediments in Dumeng sandy land makes Fe and Mg differentiation not obvious.
XIE Yuan-yun1 , MENG Jie1 , GUO Ling-fen1 , HE Kui1 , KANG Chun-guo2 . Geochemical Composition and Weathering Feature of Surface Sediment in the Dumeng Sandy Land, Northeast China[J]. Journal of Desert Research, 2013 , 33(4) : 1009 -1018 . DOI: 10.7522/j.issn.1000-694X.2013.00143
[1]Xu Z W,Lu H Y,Zhao C F,et al.Composition,origin and weathering process of surface sediment in Kumtagh Desert,Northwest China[J].Journal Geographical Sciences,2011,21(6):1062-1076.
[2]Xie J,Ding Z L.Compositions of heavy minerals in northeastern China sandlands and provenance analysis[J].Science in China: Series D,2007,50(11):1715-1723.
[3]钱亦兵,吴兆宁,石井武政,等.塔克拉玛干沙漠沙物质成分特征及其来源[J].中国沙漠,1993,13(4):32-38.
[4]王进,周瑞莲,赵哈林,等.呼伦贝尔沙地和松嫩沙地草地沙漠化过程中土壤理化特性变化规律的比较研究[J].中国沙漠,2011,31(2):309-314.
[5]曹红霞,张云翔,岳乐平,等.毛乌素沙地全新世地层粒度组成特征及古气候意义[J].沉积学报,2003,21(3):482-486.
[6]刘冰,靳鹤龄,孙忠.近6 ka以来科尔沁沙地东部气候变化记录[J].中国沙漠,2011,31(6):1398-1405.
[7]李宜垠,吕金福.松嫩沙地晚更新世以来的孢粉记录及古植被古气候[J].中国沙漠,1996,16(4):338-344.
[8]Chen J,Li G J.Geochemical studies on the source region of Asian dust[J].Science China Earth Sciences,2011,54:1279-1301.
[9]Rao W B,Yang J D,Chen J,et al.Sr-Nd isotope geochemistry of eolian dust of the arid-semiarid areas in China:implications for loess provenance and monsoon evolution[J].Chinese Science Bulletin,2006,51(12):1401-1412.
[10]杨杰东,陈骏,饶文波,等.中国沙漠的同位素分区特征[J].地球化学,2007,36(5):516-524.
[11]Li G,Chen J,Chen Y,et al.Dolomite as a tracer for the source regions of Asian dust[J].Journal of Geophysical Research,2007,112:D17201.
[12]Chen J,Li G J,Yang J D,et al.Nd and Sr isotopic characteristics of Chinese deserts:implications for the provenances of Asian dust[J].Geochim Cosmochim Acta,2007,71:3904-3914.
[13]Li G J,Chen J,Ji J F,et al.Global cooling forced increase in marine strontium isotopic ratios:importance of mica weathering and a kinetic approach[J].Earth and Planetary Science Letters,2007,254:303-312.
[14]Yang X B,Zhu B Q,White P D.Provenance of aeolian sediment in the Taklamakan Desert of western China,inferred from REE and major-elemental data[J].Quaternary International,2007,175(1):71-85.
[15]Yang S L,Ding F,Ding Z L.Pleistocene chemical weathering history of Asian arid and semi-arid regions recorded in loess deposits of China and Tajikistan[J].Geochimica et Cosmochimica Acta,2006,70:1695-1709.
[16]裘善文,王其存,陈国双,等.松嫩沙地沙漠化及防治研究——以杜尔伯特蒙古族自治县他拉哈镇为例[J].中国沙漠,2011,31(2):331-338.
[17]裘善文.中国东北西部沙地与沙漠化[M].北京:科学出版社,2008.
[18]Pye K.Aeolian Dust and Dust Deposits[M].London:Academic Press,1987:1-256
[19]Taylor S R,McLennan S M.The Continental Crust:Its Composition and Evolution[M].London:Blackwell,1985:277.
[20]Xie Y Y,Zhang Y,He K,et al.Features of sand-dust deposits in Harbin city,China[J].Chinese Geographical Sciences,2006,16(4):327-333.
[21]谢远云,何葵,周嘉,等.哈尔滨沙尘暴的化学特征及其物质源探讨[J].地理研究,2006,25(2):255-261.
[22]谢远云.第四纪气候载体的环境意义[M].哈尔滨:哈尔滨地图出版社,2007.
[23]刘连文,陈骏,王洪涛,等.一个不受风力分选作用影响的化学风化指标:黄土酸不溶物中Fe/Mg值[J].科学通报,2001,46(7):578-582.
[24]高玲,丁仲礼.最近130 ka来黄土物质化学风化的空间观察[J].第四纪研究,2008,28(1):162-168.
[25]陈发虎,张维信.甘青地区的黄土地层学与第四纪冰川问题[M].北京:科学出版社,1990.
[26]谢远云,张丽娟,何葵,等.哈尔滨城市地表土的物质组成与沙尘天气[J].中国地质,2009,36(2):474-481.
[27]Nesbitt H W,Young G M.Prediction of some weathering trends of plutonic and volcanic rocks based on thermodynamic and kinetic considerations[J].Geochimica et Cosmochimica Acta,1984,48:1523-1534.
[28]Nesbitt H W，Young G M.Early Proterozoic climates and plate motions inferred from major element chemistry of lutites[J].Nature,1982,299(21):715-717.
[29]牛光明,强明瑞,宋磊,等.5000 a来柴达木盆地东南缘风成沉积记录的冬季风演化[J].中国沙漠,2010,30(5):1031-1039.
[30]McLennan S M.Weathering and global denudation[J].Journal of Geology,1993,101:295-303.
[31]陈骏,安芷生,刘连文,等.最近2.5 Ma以来黄土高原风尘化学组成的变化与亚洲内陆的化学风化[J].中国科学(D辑),2001,31(2):136-145.
[32]陈旸,陈骏,刘连文.甘肃西峰晚第三纪红粘土的化学组成及化学风化特征[J].地质力学学报,2001,7(2):167-175.
[33]李徐生,韩志勇,杨守业,等.镇江下蜀土剖面的化学风化强度与元素迁移特征[J].地理学报,2007,62(11):1174-1184.
[34]李徐生,杨达源,鹿化煜.皖南风尘堆积序列氧化物地球化学特征与古气候记录[J].海洋地质与第四纪地质,1999,19(4):75-82.
[35]Nesbitt H,Young G.Petrogenesis of sediments in the absence of chemical weathering:effects of abrasion and sorting on bulk composition and mineralogy[J].Sedimentology,1996,43(2):341-358.
[36]李取生.松嫩沙地的形成与环境变迁[J].中国沙漠,1991,11(3):36-43.
/
| 〈 |
|
〉 |