基于碎屑锆石U-Pb年龄对黄土高原黄土的空间物源差异分析
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摘要
黄土高原地处我国中部,面积广阔。虽然前人使用多种研究方法对黄土高原的黄土物源进行了研究,但目前仍然缺乏对黄土高原黄土空间物源差异的系统研究和分析,分析黄土高原黄土的空间物源差异也对阐释粉尘的运输机制有重要意义。通过对黄土高原及周边不同区域的17个黄土样品进行了碎屑锆石U-Pb年龄测试,其年龄组成主要有7个年龄区间:0～100Ma,100～350Ma,350～600Ma,600～1 100Ma,1 100～1 500Ma,1 500～2 300Ma和2 300～2 800Ma。通过对17个样品点锆石U-Pb年龄谱的对比发现,黄土高原黄土因多种因素呈现了一定的相似性,促使黄土高原不同空间位置的黄土中碎屑锆石的U-Pb年龄谱总体上呈现相似性的原因主要为多次沉积和充分混合。但仍然在局部存在差异,主要表现为:黄土高原北部黄土与南部黄土相比,北部黄土缺少年龄小于100Ma的锆石,这组年龄的锆石可能来自鄂尔多斯盆地南缘。而最西部的西宁黄土和最东部的邙山黄土相比缺少年龄为1 500～2 300Ma、峰值为2 000Ma左右的锆石,而邙山黄土被证明主要来自黄河河漫滩,这可以证明黄河在黄土高原形成中起了重要的作用。黄土高原是多源区、多成因的,而不同区域的黄土物源组成与其最近源区的相关性最大,因此,在进行黄土高原物源分析时应充分考虑区域沉积环境。
The Loess Plateau covers a vast area in the central part of China.Our predecessors have used a variety of research methods to study the provenance of the loess from different points of view.However,systematic researches are still lacking on the spatial difference in provenance of the loess,which is critical important to the explanation of transport mechanism of the dust.A total of 17 samples are collected by the authors from both the Loess Plateau and its surrounding areas for detrital zircon U-Pb dating.Results show that there are seven zircon age groups,i.e.0-100 Ma,100-350 Ma,350-600 Ma,600-1 100 Ma,1 100-1 500 Ma,1 500-2 300 Ma and 2 300-2 800 Ma.After comparison of the zircon U-Pb age spectra of the 17 samples,it is found that the loess from the plateau has certain similarities,and the main reasons for the similarity are multiple redeposition and thorough mixing.However,there are still differences in some areas.For examples,the loess in the northern part of the plateau lacks zircons younger than 100 Ma,which may come from the southern margin of the Ordos Basin,while the western Xining loess is short of zircon with a peak value of about 2 000 Ma comparing to the eastern Mangshan loess.The Mangshan loess is mainly from the floodplain of the Yellow River,which may suggest that the Yellow River has played an important role in the formation of Loess Plateau.The loess Plateau has multiple provenances and different genesis,and the composition of the loess is dominated by its nearest source area.Therefore,the regional sedimentary environment should be fully considered when the provenance analysis of Loess Plateau is carrying out.
The Loess Plateau covers a vast area in the central part of China.Our predecessors have used a variety of research methods to study the provenance of the loess from different points of view.However,systematic researches are still lacking on the spatial difference in provenance of the loess,which is critical important to the explanation of transport mechanism of the dust.A total of 17 samples are collected by the authors from both the Loess Plateau and its surrounding areas for detrital zircon U-Pb dating.Results show that there are seven zircon age groups,i.e.0-100 Ma,100-350 Ma,350-600 Ma,600-1 100 Ma,1 100-1 500 Ma,1 500-2 300 Ma and 2 300-2 800 Ma.After comparison of the zircon U-Pb age spectra of the 17 samples,it is found that the loess from the plateau has certain similarities,and the main reasons for the similarity are multiple redeposition and thorough mixing.However,there are still differences in some areas.For examples,the loess in the northern part of the plateau lacks zircons younger than 100 Ma,which may come from the southern margin of the Ordos Basin,while the western Xining loess is short of zircon with a peak value of about 2 000 Ma comparing to the eastern Mangshan loess.The Mangshan loess is mainly from the floodplain of the Yellow River,which may suggest that the Yellow River has played an important role in the formation of Loess Plateau.The loess Plateau has multiple provenances and different genesis,and the composition of the loess is dominated by its nearest source area.Therefore,the regional sedimentary environment should be fully considered when the provenance analysis of Loess Plateau is carrying out.
引文
[1]刘东生,等.黄土与环境[M].北京:科学出版社,1985:1-148.
[2]Sun J,Li S H,Muhs D R,et al.Loess sedimentation in Tibet:Provenance,processes,and link with Quaternary glaciations[J].Quaternary Science Review,2007,26(17/18):2265-2280.
[3]李高军.东亚风尘物源地球化学示踪研究[D].南京:南京大学,2010.
[4]汪海斌,于英鹏,刘现彬,等.黄土高原S1古土壤的地球化学特征及其对物源的指示[J].第四纪研究,2011,31(2):338-346.
[5]彭文彬.中国黄土高原黄土红黏土QEMSCAN重矿物研究[D].兰州:兰州大学,2014.
[6]Pullen A,Kapp P,Mccallister A T,et al.Qaidam Basin and northern Tibetan Plateau as dust sources for the Chinese Loess Plateau and paleoclimatic implications[J].Geology,2011,39(11):1031-1034.
[7]Derbyshire E,Meng X,Kemp R A.Provenance,transport and characteristics of modern aeolian dust in western Gansu Province,China,and interpretation of the Quaternary loess record[J].Journal of Arid Environments,1998,39(3):497-516.
[8]Stevens T,Carter A,Watson T P,et al.Sevastjanova.Genetic linkage between the Yellow River,the Mu Us desert and the Chinese Loess Plateau[J].Quaternary Science Reviews,2013,78(15):355-368.
[9]Bird A,Stevens T,Rittner M,et al.Quaternary dust source variation across the Chinese Loess Plateau[J].Palaeogeography,Palaeoclimatology,Palaeoecology,2015,435(1):254-264.
[10]Che X D,Li G J.Binary sources of loess on the Chinese Loess Plateau revealed by U-Pb[J].Quaternary Reaserch,2013,80:545-551.
[11]侯可军,李延河,田有荣.LA-MC-ICP-MS锆石微区原位U-Pb定年技术[J].矿床地质,2009,28(4):481-492.
[12]Geslin J K,Link P K,Fanning C M.High-precision provenance determination using detrital-zircon ages and petrography of Quaternary sands on the eastern Snake River Plain,Idaho[J].Geology,1999,27(4):295-298.
[13]M9ller A,O'Brien P J,Kennedy A,et al.Polyphase zircon in ultrahigh-temperature granulites(Rogaland,SW Norway):constraints for Pb diffusion in zircon[J].Journal of Metamorphic Geology,2002,20(8):727-740.
[14]杨石岭,丁仲礼.黄土高原黄土粒度的空间变化及其古环境意义[J].第四纪研究,2017,37(5):934-944.
[15]汪海斌,于英鹏,刘现彬,等.黄土高原S1古土壤的地球化学特征及其对物源的指示[J].第四纪研究,2011,31(2):338-346.
[16]饶文波,杨杰东,陈骏,等.中国干旱-半干旱区风尘物质的Sr,Nd同位素地球化学:对黄土来源和季风演变的指示[J].科学通报,2006,51(4):378-386.
[17]杨杰东,李高军,戴澐,等.黄土高原黄土物源区的同位素证据[J].地学前缘,2009,16(6):195-206.
[18]张建新,孟繁聪,万渝生,等.柴达木盆地南缘金水口群的早古生代构造热事件:锆石U-Pb SHRIMP年龄证据[J].地质通报,2003,22(6):397-404.
[19]孙国强.柴达木盆地中新生代构造运动学过程及原型盆地类型研究[D].兰州:中国科学院研究生院(兰州地质研究所),2004.
[20]李怀坤,陆松年,相振群,等.北祁连山西段北大河岩群碎屑锆石SHRIMP U-Pb年代学研究[J].地质论评,2007,53(1):134-142.
[21]王云山.青藏高原北部构造发展的主要阶段[J].青海国土经略,1991(2):14-24.
[22]张培震,张会平,郑文俊,等.东亚大陆新生代构造演化[J].地震地质,2014,36(3):574-585.
[23]黄志刚,任战利,高龙刚.鄂尔多斯盆地东南缘白垩纪以来构造演化的裂变径迹证据[J].地球物理学报,2016,59(10):3753-3764.
[24]孙少华,李小明,龚革联.鄂尔多斯盆地构造热事件研究[J].科学通报,1997,42(3):306-309.
[25]张岳桥,廖昌珍.晚中生代-新生代构造体制转换与鄂尔多斯盆地改造[J].中国地质,2006,33(1):28-40.
[26]李高军,车旭东,肖国桥,等.西宁黄土碎屑锆石年龄特征及其对黄土高原黄土物源的指示意义[J].第四纪研究,2013,33(2):345-350.
[27]李高军,李乐,徐树建,等.中国东部黄土物源铀同位素碎粒年代学研究[J].第四纪研究,2017,37(5):1037-1044.
[28]岳保静,廖晶.黄河流域现代沉积物碎屑锆石U-Pb年龄物源探讨[J].海洋地质与第四纪地质,2016,36(5):109-119.
[2]Sun J,Li S H,Muhs D R,et al.Loess sedimentation in Tibet:Provenance,processes,and link with Quaternary glaciations[J].Quaternary Science Review,2007,26(17/18):2265-2280.
[3]李高军.东亚风尘物源地球化学示踪研究[D].南京:南京大学,2010.
[4]汪海斌,于英鹏,刘现彬,等.黄土高原S1古土壤的地球化学特征及其对物源的指示[J].第四纪研究,2011,31(2):338-346.
[5]彭文彬.中国黄土高原黄土红黏土QEMSCAN重矿物研究[D].兰州:兰州大学,2014.
[6]Pullen A,Kapp P,Mccallister A T,et al.Qaidam Basin and northern Tibetan Plateau as dust sources for the Chinese Loess Plateau and paleoclimatic implications[J].Geology,2011,39(11):1031-1034.
[7]Derbyshire E,Meng X,Kemp R A.Provenance,transport and characteristics of modern aeolian dust in western Gansu Province,China,and interpretation of the Quaternary loess record[J].Journal of Arid Environments,1998,39(3):497-516.
[8]Stevens T,Carter A,Watson T P,et al.Sevastjanova.Genetic linkage between the Yellow River,the Mu Us desert and the Chinese Loess Plateau[J].Quaternary Science Reviews,2013,78(15):355-368.
[9]Bird A,Stevens T,Rittner M,et al.Quaternary dust source variation across the Chinese Loess Plateau[J].Palaeogeography,Palaeoclimatology,Palaeoecology,2015,435(1):254-264.
[10]Che X D,Li G J.Binary sources of loess on the Chinese Loess Plateau revealed by U-Pb[J].Quaternary Reaserch,2013,80:545-551.
[11]侯可军,李延河,田有荣.LA-MC-ICP-MS锆石微区原位U-Pb定年技术[J].矿床地质,2009,28(4):481-492.
[12]Geslin J K,Link P K,Fanning C M.High-precision provenance determination using detrital-zircon ages and petrography of Quaternary sands on the eastern Snake River Plain,Idaho[J].Geology,1999,27(4):295-298.
[13]M9ller A,O'Brien P J,Kennedy A,et al.Polyphase zircon in ultrahigh-temperature granulites(Rogaland,SW Norway):constraints for Pb diffusion in zircon[J].Journal of Metamorphic Geology,2002,20(8):727-740.
[14]杨石岭,丁仲礼.黄土高原黄土粒度的空间变化及其古环境意义[J].第四纪研究,2017,37(5):934-944.
[15]汪海斌,于英鹏,刘现彬,等.黄土高原S1古土壤的地球化学特征及其对物源的指示[J].第四纪研究,2011,31(2):338-346.
[16]饶文波,杨杰东,陈骏,等.中国干旱-半干旱区风尘物质的Sr,Nd同位素地球化学:对黄土来源和季风演变的指示[J].科学通报,2006,51(4):378-386.
[17]杨杰东,李高军,戴澐,等.黄土高原黄土物源区的同位素证据[J].地学前缘,2009,16(6):195-206.
[18]张建新,孟繁聪,万渝生,等.柴达木盆地南缘金水口群的早古生代构造热事件:锆石U-Pb SHRIMP年龄证据[J].地质通报,2003,22(6):397-404.
[19]孙国强.柴达木盆地中新生代构造运动学过程及原型盆地类型研究[D].兰州:中国科学院研究生院(兰州地质研究所),2004.
[20]李怀坤,陆松年,相振群,等.北祁连山西段北大河岩群碎屑锆石SHRIMP U-Pb年代学研究[J].地质论评,2007,53(1):134-142.
[21]王云山.青藏高原北部构造发展的主要阶段[J].青海国土经略,1991(2):14-24.
[22]张培震,张会平,郑文俊,等.东亚大陆新生代构造演化[J].地震地质,2014,36(3):574-585.
[23]黄志刚,任战利,高龙刚.鄂尔多斯盆地东南缘白垩纪以来构造演化的裂变径迹证据[J].地球物理学报,2016,59(10):3753-3764.
[24]孙少华,李小明,龚革联.鄂尔多斯盆地构造热事件研究[J].科学通报,1997,42(3):306-309.
[25]张岳桥,廖昌珍.晚中生代-新生代构造体制转换与鄂尔多斯盆地改造[J].中国地质,2006,33(1):28-40.
[26]李高军,车旭东,肖国桥,等.西宁黄土碎屑锆石年龄特征及其对黄土高原黄土物源的指示意义[J].第四纪研究,2013,33(2):345-350.
[27]李高军,李乐,徐树建,等.中国东部黄土物源铀同位素碎粒年代学研究[J].第四纪研究,2017,37(5):1037-1044.
[28]岳保静,廖晶.黄河流域现代沉积物碎屑锆石U-Pb年龄物源探讨[J].海洋地质与第四纪地质,2016,36(5):109-119.