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Hydrochemical characteristics and recharge sources of Lake Nuoertu in the Badain Jaran Desert 总被引:1,自引:0,他引:1
Yue Wu Naiang Wang Liqiang Zhao Zhenyu Zhang Li Chen Ying Lu Xiaonan L Jinlong Chang 《科学通报(英文版)》2014,59(9):886-895
We present a case study of physical and chemical indicators and isotope characteristics of Lake Nuoertu,one of the largest and deepest lakes of the Badain Jaran Desert.We analyze the concentrations of eight ions,total dissolved solids,and stable isotope composition of the lake and groundwater,as well as radioactive isotope tritium concentration in groundwater.The results show that annual and seasonal variations of the physical and chemical characteristics of Lake Nuoertu water are significantly greater than those of groundwater.The lake is uniformly mixed in the horizontal and vertical directions,and the hydrochemical types of the lake at different depths are consistent for Na–Cl–CO3–(SO4).Stable isotope composition of the lake and groundwater at Nuoertu is distributed along the local evaporation line(EL)slope,which is less than the slope of the global meteoric water line.The comparatively small slope shows the characteristic strong evaporation in the study area.Lake water isotopes are mostly in the upper right corner of the EL,whereas groundwater is mostly in the lower left corner.The main recharge source of Nuoertu lake water is groundwater,in combination with lake water and groundwater level change.The age of tufa springs around Nuoertu is about75–80 a,which shows that the initial recharge source of the lake is a mix between modern and 1952 or older;however,further research is required. 相似文献
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甘肃北山地区同位素定年与构造岩浆热事件 总被引:22,自引:1,他引:22
在面积约100000Km~2的甘肃北山地区,共搜集同位素年龄数据216个,其中22个是本次测定的。依据这些资料做了年龄频谱图和地质环境一岩浆热事件综合示意图,从这些结果中可以得出以下看法:1.哈萨克斯坦板块的东端前寒武纪褶皱基底以微大陆的形式延入了本区,即本区有两大构造单元—塔里木板块和哈萨克斯坦板块。2.虽然有30多属燕山期的表现年龄,但从年龄频谱的骤然下落和野外复查表明,这些是后期岩脉和矿脉的年龄,而不是大规模岩浆活动的记录,即本区没有燕山期的大规模的岩浆活动。3.从加里东到印支期的每一构造岩浆旋回中,岩浆活动似有滞后现象,甚至延至下一个旋回,很可能这种滞后具有普遍意义。4.在每一构造单元内,大陆边缘区、过渡壳区和海洋区的喷发、侵入及变质作用也不尽相同。海洋区内喷发作用强于侵入和变质作用,而大陆边缘区侵入作用强于变质和喷发作用。 相似文献
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为寻找一种经济又有效的裂缝期次定量划分方法,本文以重庆天府地区上二叠统长兴组地层为例,对构造裂缝形成期次的划分方法进行了研究。在大量野外观察与测量的基础上,以基于概率统计学的马尔科夫链为方法,进行了转移频数统计、马尔科夫性质检验、随机值计算、残差矩阵分析,得出研究区的裂缝发育期次主要为三期:第一期裂缝为近东西向,第二期裂缝为北西西-南东东向,第三期裂缝为北北东向-南南东向;结合基于地球化学的充填物碳氧同位素分析,取对应期次的裂缝充填物进行实验,对上述分析结果进行佐证,结果发现其同位素值主要散落在三个区域:第一期裂缝充填物δ18O平均值为-8.58‰,δ13C平均值为3.32‰,形成时平均埋深为3864m,形成温度为130℃;第二期裂缝充填物δ18O平均值为-7.16‰,δ13C平均值为3.79‰,形成时平均埋深为3084m,形成温度为107℃;第三期裂缝充填物δ18O平均值为-5.18‰,δ13C平均值为3.70‰,形成时平均埋深为2147m,形成温度为79℃。综合研究区构造演化史以及埋藏史分析认为:第一期裂缝形成于燕山早期,第二期裂缝形成于燕山晚期,第三期裂缝形成于喜山早期。实验结果成功验证了马尔科夫链的分析,因此马尔科夫链为一种可行的裂缝期次研究方法。 相似文献
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高纯Y2O3微量元素的火花源质谱法测定 总被引:1,自引:0,他引:1
利用同位素稀释法和内标法相结合,建立了火花源质谱法定量测定高纯Y2O3中20种微量元素的分析方法.大多数元素检测限为0.00xμg/g,相对标准偏差在20%以内 相似文献
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用示踪分析技术评价油藏特征 总被引:6,自引:0,他引:6
根据常规示踪剂分析技术存在的问题,提出了描述示踪剂运移规律的数学模型,对影响示踪剂运移规律的因素进行了平面网格加密、纵向网格加密、示踪物质的弥散性、纵向非均质性和平面非均质性的矿场规模的灵敏性分析,并用实验室五点井网平板模型进行了对比分析.结果表明.本模型可以很好地解决注水油田精细描述所面临的问题. 相似文献
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Chen Yongquan Jiang Shaoyong Ling Hongfei Yang Jinghong Wan Defan 《自然科学进展(英文版)》2007,17(10):1185-1191
Anabarites belong to small shelly fossils (SSF), which occur widely in the Lower Cambrian strata of Yangtze Platform in South China. They are phosphate shell in composition and represent the earliest stage of the Cambrian bioradiation of Bilateria, the so-called "Cambrian Explosion". In this study, we attempted to separate Anabarites fossils from Lower Cambrian dolostones, and we obtained samples of both the fossils (SSF) and the granular phosphates (GP). Isotopic analyses were performed on samples of SSF, GP, and matrix dolostone (DH-23). The results showed that the δ30Si values of the quartz filling in fossils celoms, and the siliceous materials in granular phosphates are -0.6‰ and -0.7‰, which is different from normal sedimentary siliceous rocks from the Lower Cambrian strata (0—0.7‰) as reported by Li et al., but is consistent with the data for siliceous rocks and cherts of submarine hydrothermal origin. It is likely that a later hydrothermal replacement could have taken place in the SSF-bearing sedimentary rocks. The oxygen isotope values of the phosphate of SSF and GP are 16.8‰ and 17.0‰, respectively. These are significantly higher than the Neoproterozoic phosphate ores (10.9‰—13.9‰) as reported by Ling et al., hence, late diagenesis and hydrothermal replacement may not have caused a significant change in the oxygen isotope compositions of the small shelly fossils, and the calculated temperatures (25.4—26.3℃) for palaeo-seawater using a SSF phosphate oxygen isotope thermometer are therefore considered here as the upper limit of seawater temperature in the Early Cambrian ocean of the Yangtze Platform. 相似文献
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