Applying end-member modeling to extricate the sedimentary environment of yardang strata in the Dunhuang Yardang National Geopark, northwestern China
Applying end-member modeling to extricate the sedimentary environment of yardang strata in the Dunhuang Yardang National Geopark, northwestern China
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应用端元模型解救敦煌雅丹国家地质公园雅丹地层沉积环境
DOI：
10.1016/j.catena.2019.04.029
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发表时间：
2019-09
期刊：
影响因子：
6.2
通讯作者：
Niu Baicheng
中科院分区：
文献类型：
--
作者：
Liang Xiaolei;Niu Qinghe;Qu Jianjun;Liu Bing;Liu Benli;Zhai Xiaohui;Niu Baicheng
中国西北干旱半干旱区雅丹地貌分布独特，成因不明，其形成机制和沉积环境至今仍不清楚。雅丹沉积物是由风成作用还是由水成作用形成的，目前还没有可靠的定量方法来解决这个问题。通过对雅丹组地层与现代表层沉积物的对比分析，利用端元模拟分析（EMMA）对雅丹组的沉积环境进行了描述。结果表明，雅丹地区沉积物端员与表层沉积物端员具有良好的对应关系，雅丹地区的沉积环境可分为风成、风成和风成三种类型（200-550 μm（众数值范围）），冲积层（150-300 μm和8-20 μm），湖相（再细分为海岸线：80-110微米;湖心：3-15微米;过渡区（沿岸的和湖沼区之间的过渡区）：15-60微米）。在此基础上，我们确定了湖泊，风成和冲积物的浓度分别为63.92%，20.80%和15.28%（YA剖面）和53.68%，28.30%和18.02%（YB剖面）。此外，两个剖面的沉积过程之间存在显着差异，其中YA具有更多的湖泊沉积物和YB具有更多的风成沉积物，可能是古地形造成的。一般来说，雅丹是由湖相、风成和冲积沉积物交替形成的。虽然湖泊沉积物占主导地位，风成沉积物也占相当大的比例。这一研究为雅丹地貌的形成和发展提供了新的认识，也为古地貌格局的重建提供了依据。
Formative mechanisms and sedimentary environments of yardang landform distribution in arid and semiarid regions of northwestern China remain poorly understood due to their unique formation and enigmatic causation. Considerable controversy remains as to whether yardang deposits evolve from aeolian or aqueous forces, and no reliable, quantitative method has yet been made available to resolve this issue. This study conducted a comparative analysis between yardang strata and modern surface sediments to characterize the sedimentary environment using end-member modeling analysis (EMMA). Results show that yardang and surface sediment end-members corresponded well, and that the yardang depositional environment can be classified into three typical types: aeolian (200–550 μm (mode value range)), alluvial (150–300 μm and 8–20 μm), and lacustrine (subclassified into shoreline: 80–110 μm; lake center: 3–15 μm; and transitional (the transition between the littoral and limnetic zones): 15–60 μm). Based on this method, we determined that lacustrine, aeolian, and alluvial concentrations were 63.92%, 20.80%, and 15.28% (YA profile, respectively) and 53.68%, 28.30%, and 18.02% (YB profile, respectively). Additionally, a significant difference was found between the sedimentary processes of the two profiles, where YA had more lacustrine sediments and YB had more aeolian sediments, likely resulting from paleotopography. Generally, yardang derives from alternating lacustrine, aeolian, and alluvial sedimentary deposits. Although lacustrine sediments predominated, aeolian sediments also accounted for a considerable overall proportion. This study provides new insight into the formation and development of yardang landforms as well as evidence for the reconstruction of paleo-geomorphologic patterns.
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影响因子：
2.8
作者：
G. Weltje;M. Prins
通讯作者：
G. Weltje;M. Prins
影响因子：
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作者：
A. W. Ward
通讯作者：
A. W. Ward
测试将颗粒尺寸成分与现代碎屑湖湖水位状况联系起来的模型
影响因子：
2.2
作者：
Fan, J.W.;Zhai, D.Y.;Wen, R.L.;Qin, X.G.
通讯作者：
Qin, X.G.
影响因子：
2.3
作者：
Xiaonan Zhang;Aifeng Zhou;Can Zhang;S. Hao;Yongtao Zhao;C. An
通讯作者：
Xiaonan Zhang;Aifeng Zhou;Can Zhang;S. Hao;Yongtao Zhao;C. An
影响因子：
2
作者：
B. Sahu
通讯作者：
B. Sahu