摘要
内蒙古五原县塔尔湖地区发育一系列湖泊,与当地干旱气候形成鲜明的对比,湖泊成因机制对河套地区第四纪水文地质、气候环境研究具有重要意义。对色尔腾山山前—塔尔湖湖泊—黄河沿线不同水体样品进行水化学测试后,利用Gibbs模型投影显示湖泊采样点主要落在蒸发-浓缩端元和岩石风化端元的过渡带,而远离大气降水作用带,地下水更靠近岩石风化端元,说明湖泊接受地下水补给,蒸发强烈;Piper三线图显示山前泉水以HCO_3—Ca型为主,河套平原地下水以HCO_3—Na、Cl—Na型为主,黄河水为HCO_3—Na型,湖泊以Cl—Na型为主,说明塔尔湖地区地下水与湖泊存在水力联系,HCO_3—Na型地下水经过蒸发浓缩作用转变成了盐度更高的Cl—Na型湖泊,导致盐分的聚集;地下水可溶性固体总量(TDS)自北向南由262 mg/l快速增加至2 296 mg/l,而湖泊TDS先升后降,最后小于地下水TDS,最大值在塔尔湖地区北部,为1 213 mg/l,说明湖泊还受现代黄河补给,地下水TDS变化满足山前—盆地的水文地质模型。塔尔湖地区的湖泊既可以发育于古河床亚相也可以发育于堤坝亚相,且湖泊呈零星分布,与古河道形成的牛轭湖特征不吻合,从而基本排除湖泊为古黄河残留的可能;潜水面之上的河流相沉积物由于风蚀作用被切穿,导致地下水出露,补给湖泊,从而推断塔尔湖地区湖泊主要为风蚀湖。
There are a series of lakes in Taerhu,Wuyuan of Inner Mongolia in the Hetao Plain,which is an obvious comparison to the local arid climate. Researching on the mechanism of lakes is important to hydrogeology and climate changes in Quaternary period. By carrying out chemical tests on the samples along the way from Serteng Mountain to Taerhu lakes and to Yellow River,the results show that Gibbs model projection indicates lake-water samples lie in the transition of evaporation and rock weathering effects,which is far away from the effect of precipitation while groundwater is mainly controlled by rock weathering effects,showing groundwater recharges lake water that suffers extremely evaporation; Piper trilinear diagram reveals hydrochemical types are mainly HCO_3—Ca for springs in front of mountains,HCO_3—Na and Cl—Na for groundwater,HCO_3—Na for Yellow River water and Cl—Na for lake water,which also shows there exists hydraulic relationship betweengroundwater and lake water that contains great concentration of the salt during the process of being recharged;TDS of the groundwater rapidly increases from the north to the south,varying from 262 mg/l to 2,296 mg/l.The lakes＇ TDS,however,after reaching the maximum value of 1,213 mg/l in the north of Taerhu,decreases and is finally lower than that of groundwater,which shows lake water is recharged by present Yellow River and the change of groundwater conforms to hydrogeology model. The results of Quaternary geological survey show lakes can not only develop upon the riverbed subfacies,but also upon the dam facies in Taerhu. In addition,the distribution features of scattered lakes are not similar to those of oxbow lakes. The two arguments above basically eliminate the possibility that lakes are left by the ancient Yellow River. Alluvial deposit was ever eroded by the wind,which led in occurrence of underlain groundwater. In conclusion,the basins of lakes were formed by wind erosion.
出处
《现代地质》
CAS
CSCD
北大核心
2016年第5期1170-1178,共9页
Geoscience
基金
国土资源部公益性行业科研专项"我国不同季风区古气候演化差异及成因机制研究"(201211077-3)
中国地质调查局"内蒙古1:5万呼勒斯太苏木
塔尔湖镇等四幅填图试点"项目(12120114042101)
内蒙古国土资源厅"狼山晚更新世(Qp3)以来新构造运动及其环境效应研究"项目(BSZFCG2015-HW-00403)
