The Mu US Desert located in the semi-arid area of northwest edge of China's monsoon region is typically sensitive to the global climate change, so this area is usually regarded as ideal area for research of climate change and desert evolution. The Jinjie profile (38°44'45″N, 110°09'56″E) of Shenmu County that located in Southeastern of Mu US Desert, has developed representative aeolian sand-paleosoil sedimentary structure. We analyzed sediment in Jinjie profile, based on data of OSL dating, geochemical major element oxides and the ratio of these elements, in combination with magnetic susceptibility and grain size. The result showed that:(1)The sediment of Jinjie profile was mainly composed of SiO2 and Al2O3, with the contents of 69.72%-81.40% and 11.04%-12.71%, the other major element oxides' contents are in order of Na > K > Fe > Ca > Mg. Chemical activity of different geochemical elements in the section showed obvious variability:K, Na and Si were more migrated and leached; while Ca, Mg, Fe, Al were obviously enriched. (2)The geochemical parameters can be used as the sensitive index to indicate the variability of Asian summer monsoon and winter monsoon. (3)The climate change in Southeastern of Mu US Desert since 7.9 ka BP can be classified into 6 stages:7.9-7.3 ka BP, the paleosoil layer is developed, the summer monsoon was powerful and the climate was warmest and wettest during this period, chemical weathering is strong and indicating accessing to the Holocene Optimum; 7.3-6.8 ka BP, the aeolian sand is developed, and the winter monsoon became stronger and the climate was cold and dry; 6.8-4.3 ka BP, the climate was warm and wet as a whole but still occurs two climatic fluctuations which become dry and cold from warm and wet, more than, there were six aeolian events were recorded at 6.6-6.3 ka BP, 6.1 ka BP, 5.9 ka BP, 5.7-5.5 ka BP, 5.3-5.0 ka BP, 4.7-4.4 ka BP; 4.3-2.5 ka BP, the winter monsoon became stronger again, the cold and dry climate was dominated; 2.5-1.8 ka BP, the climate was warm and humid, but the summer monsoon is weaker than the Holocene Optimum; Since 1.8 ka BP, the climate becomes colder and arider. The climate change in the study area reflects the strong and weak changes of East Asian monsoon and is coincident with the regional and global climate change.
[1] 秦大河,Thomas Stocker.IPCC第五次评估报告第一工作组报告的亮点结论[J].气候变化研究进展,2014,10(1):1-6.
[2] 金章东,王苏民,沈吉,等.全新世岱海流域化学风化及其对气候事件的响应[J].地球化学,2004,33(1):29-36.
[3] Bond G,Showers W,Cheseby M,et al.A pervasive millennial-scale cycle in North Atlantic Holocene and Glacial climates[J].Science,1997,278(3):1257-1266.
[4] O'Brien S R,Mayewski P A,Meeker L D,et al.Complexity of Holocene climate as reconstructed from a Greenland ice core[J].Science,1995,270(5244):1962-1964.
[5] 姚檀栋,Thompson L G,施雅风,等.古里雅冰芯中末次间冰期以来气候变化记录研究[J].中国科学D辑:地球科学,1997,27(5):447-452.
[6] Bond G,Kromer B,Beer J,et al.Persistent solar influence on North Atlantic climate during the Holocene[J].Science,2001,294(5549):2130-2136.
[7] 黄春长,庞奖励,黄萍,等.关中盆地西部黄土台塬全新世气候事件研究[J].干旱区地理,2002,25(1):10-15.
[8] 刘冰,靳鹤龄,孙忠.中晚全新世科尔沁沙地沉积物化学特征及其气候变化[J].沉积学报,2012,30(3):536-546.
[9] 牛东风,李保生,王丰年,等.微量元素记录的毛乌素沙漠全新世气候波动——以萨拉乌苏流域DGS1层段为例[J].沉积学报,2015,33(4):735-743.
[10] 陈发虎,朱艳,李吉钧,等.民勤盆地湖泊沉积记录的全新世千百年尺度夏季风快速变化[J].科学通报,2001,46(17):1414-1419.
[11] 邵晓华,汪永进,程海,等.全新世季风气候演化与干旱事件的湖北神农架石笋记录[J].科学通报,2006,51(1):80-86.
[12] 杨劲松,王永,赵红梅.晚更新世以来萨拉乌苏河流域主元素的地球化学特征及古环境意义[J].干旱区资源与环境,2016,30(11):148-153.
[13] 何元庆,姚檀栋,沈永平,等.冰芯与其他记录所揭示的中国全新世大暖期变化特征[J].冰川冻土,2003,25(1):11-18.
[14] 王绍武.全新世大暖期[J].气候变化研究进展,2011,7(5):383-384.
[15] 杨帆,靳鹤龄,李孝泽,等.中晚全新世毛乌素沙地东南部气候变化过程[J].中国沙漠,2017,37(3):431-438.
[16] 陈骏,季峻峰,仇纲,等.陕西洛川黄土化学风化程度的地球化学研究[J].中国科学:D辑,1997,27(6):531-536.
[17] 靳鹤龄,李明启,苏志珠,等.220ka BP来萨拉乌苏河流域地质剖面地球化学特征及其对全球气候变化的响应[J].冰川冻土,2005,27(6):861-868.
[18] 李后信,李保生,祝一志,等.150ka BP以来萨拉乌苏河流域主元素变动旋回[J].地球化学,2002,31(5):424-432.
[19] 陈渭南,高尚玉,孙忠.毛乌素沙地全新世地层化学元素特点及其古气候意义[J].中国沙漠,1994,14(1):22-30.
[20] 吉云平,杨振京,赵华,等.河北阳原盆地井儿洼剖面常量元素地球化学特征揭示的中更新世晚期以来气候变化[J].古地理学报,2016,18(3):487-496.
[21] 刘冰,靳鹤龄,孙忠.中晚全新世科尔沁沙地演化与气候变化[J].中国沙漠,2013,33(1):77-86.
[22] 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.
[23] Mclennan S M.Weathering and global denudation[J].Journal of Geology,1993,101:295-303.
[24] 陈璐,鲁瑞洁,刘小槺,等.萨拉乌苏河流域全新世气候变化的元素地球化学记录[J].北京师范大学学报:自然科学版,2017,53(3):308-315.
[25] An Zhisheng,Colman S,Zhou Weijian,et al.Interplay between the Westerlies and Asian monsoon recorded in Lake Qinghai sediments since 32 ka[J].Scientific Reports,2012,2(8):619.
[26] 吕厚远,张健平.关中地区的新石器古文化发展与古环境变化的关系[J].第四纪研究,2008,28(6):1050-1060.
[27] Lu Houyuan, Wu Naiqin, Liu Kambiu,et al.Phytoliths as quantitative indicators for the reconstruction ofpast environmental conditions in China Ⅱ:Palaeoenvironmental reconstruction in the Loess Plateau[J].Quaternary Science Reviews,2007,26(5/6):759-772.
[28] 马冀,岳乐平,杨利荣,等.毛乌素沙漠东南缘全新世剖面光释光年代及古气候意义[J].第四纪研究,2011,31(1):120-129.
[29] Jia F F,Lu R J,Gao S Y,et al.Holocene Aeolian activities in the Southeastern Mu Us Desert,China[J].Aeolian Research,2015,19:267-274.
[30] 隆浩,王乃昂,李育,等.毛乌素沙地北缘泊江海子剖面粒度特征及环境意义[J].中国沙漠,2007,27(2):187-193.
[31] 鲁瑞洁,王亚军,张登山.毛乌素沙地15 ka以来气候变化及沙漠演化研究[J].中国沙漠,2010,30(2):273-277.
[32] 李明启,靳鹤龄,张洪,等.浑善达克沙地磁化率和有机质揭示的全新世气候变化[J].沉积学报,2005,23(4):683-689.
[33] 王绍武.全新世北大西洋冷事件:年代学和气候影响[J].第四纪研究,2009,29(6):1146-1153.
[34] 赵琦,樊荣,李保生,等.内蒙古萨拉乌苏河流域滴哨沟湾全新世早-中期湖相沉积的地球化学古气候响应[J].海洋地质与第四纪地质,2013,33(4):103-112.
[35] 黄昌庆,冯兆东,马玉贞,等.巴汗淖孢粉记录的全新世环境变化[J].兰州大学学报:自然科学版,2009,45(4):7-12.
[36] 王丰年,李保生,牛东风,等.萨拉乌苏河流域MGS1层段粒度与CaCO3记录的全新世千年尺度的气候变化[J].中国沙漠,2012,32(2):331-339.
[37] 丁大林,李广雪,徐继尚,等.全新世亚洲季风演变[J].地学前缘,2017,24(4):114-123.
甘公网安备 62010202000688号