Hydrogeology and hydrogeochemistry of the Spring Mountains, Clark County, Nevada
Hydrogeology and hydrogeochemistry of the Spring Mountains, Clark County, Nevada
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内华达州克拉克县斯普林山的水文地质和水文地球化学
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
R. Hershey
中科院分区：
文献类型：
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作者：
R. Hershey
斯普林山脉是内华达州南部最大的地下水补给区，为拉斯维加斯、帕朗普和印第安泉谷提供了大量的地下水。山脉主要由高度断裂和断层的碳酸盐岩组成，被认为是内华达州东部区域碳酸盐含水层系统的一部分。由于斯普林山脉的补给潜力，它们靠近拉斯维加斯，以及它们与区域含水层系统的相互作用，对山脉水文地质的了解至关重要。对山脉和相关山谷的116个泉水和威尔斯井进行的同位素和化学分析表明，地下水的质量一般良好，温暖的天气降水正在补充较高海拔的地下水系统，在拉斯维加斯山谷的北方，包括较老的区域水在内的几种地下水团正在混合。研究区地下水的高质量是由山块中部碳酸盐岩的优势控制的。水质下降，因为岩石的变化，石英岩和页岩在北部和碎屑岩和蒸发岩在南部。研究区地下水、雪和雨的平均8D和8180的比较表明，需要40%的雨和60%的雪的混合物来获得地下水。对鹿溪泉1号的降水和地下水的8D和8180的详细研究也表明，一些夏季降水正在补充地下水系统。8.高海拔泉水的13C表明在较高海拔处有大量的补给。地下水8t3C模拟结果表明，土壤中8t3C含量较低，高海拔地区为开放系统条件。地下水中14 C分析和地下水地球化学模拟使用PHREEQE和BALANCE表明，来自Spring Mountain基岩含水层和冲积扇含水层的地下水与来自拉斯维加斯剪切带的区域含水层的水混合。模型还表明，在拉斯维加斯井场，90%的拉斯维加斯剪切带水与来自拉斯维加斯山谷西部的10%的水混合。
The Spring Mountains are the largest ground-water recharge area in southern Nevada and supply a significant amount of ground water to the Las Vegas, Pahrump, and Indian Springs Valleys. The m ountain range, composed predominantly of highly fractured and faulted carbonate rock, is considered part of a regional carbonate aquifer system found in eastern Nevada. Because of the Spring Mountains recharge potential, their proximity to Las Vegas, and their interaction with the regional aquifer system, an understanding of the hydrogeology of the mountain range is vital. Isotopic and chemical analyses from 116 springs and wells in the mountain range and associated valleys indicate that ground water is generally of good quality, warm weather precipitation is recharging the ground-water system at higher elevations, and mixing of several ground-water masses including older regional water is occurring in the northern Las Vegas Valley. The high quality of ground water in the study area is controlled by the predominance of carbonate rock in the central portion of the mountain block. W ater quality decreases as lithologies change to quartzite and shale in the north and to clastic and evaporite rocks in the south. Comparisons of average 8 D and 8 180 of ground water, snow, and rain in the study area suggest tha t a mixture of 40 percent rain and 60 percent snow is needed to derive ground water. A detailed study of 8D and 8 180 of precipitation and ground water at Deer Creek Spring #1 also suggest some summer precipitation is recharging the ground water system. 8 13C of high elevation springs suggest large amounts of recharge at higher elevations. Modeling of 8 t3C in ground water suggest low P co 2 anc ̂ enriched 8 13C in soil, and open system conditions at high elevations. Analysis of 14C in ground water and geochemical modeling of ground water using PHREEQE and BALANCE suggest tha t ground water from the Spring Mountain bedrock aquifer and alluvial-fan aquifers are mixing with water from the regional aquifer in the Las Vegas shear zone. Modeling also suggests mixing of 90 percent Las Vegas shear zone water with 10 percent water from the western portion of the Las Vegas Valley in the Las Vegas well field.