In the High Plains (HP) region of northeastern New Mexico (NE NM), USA, underlying bedrock aquifers are utilized where the High Plains Aquifer is thin, absent, or unsaturated. These usage patterns, aquifer depletion, and increasing regional aridity imply that NE NM is a possible analogy for more easterly portions of the central HP. To examine the relationship between recharge, residence time, and hydrogeologic setting, 85 well and spring samples were analyzed for environmental tracers (δD, δ¹⁸O, δ¹³C, and limited tritium and carbon-14 activities). Approximately half of the wells were open to strata of the Dakota Group. δD was −105.0 to −41.7‰ (median −58.2‰) and δ¹⁸O was −13.7 to −4.4‰ (median −8.1‰). Overall, isotopic composition is correlated with elevation and influenced by hydrogeologic setting. Ten anomalously depleted waters, most near volcanic-capped mesas, may represent higher-elevation or winter-biased recharge, a different modern precipitation source, or recharge from a cooler climate. Recharge, estimated by chloride mass balance using groundwater chloride concentrations, averages 6 mm/year below 2,000-m elevation and 16 mm/year above 2,000 m. Tritium (nondetectable to 5.7 tritium units) and carbon-14 activities (modern carbon fraction 0.23–1.05) suggest that Holocene to modern waters occur, possibly as mixtures, and that alluvial channels and other surficial features promote recharge, likely at higher rates than regional averages. It is noteworthy that isotopically depleted waters in this study tended to be tritium-free. Additional residence time tracers and seasonal precipitation isotopic sampling could address recharge and the origin of depleted waters.

在美国新墨西哥州东北部（NE NM）的高平原（HP）地区，在高平原含水层薄，不存在或不饱和的地方，利用了基岩含水层。这些使用模式，含水层枯竭以及区域干旱加剧，都暗示NE NM是中央HP偏东地区的一种可能比喻。为了检查充值，停留时间和水文地质设置之间的关系，以及85和弹簧分析样品的环境示踪剂（δD，δ ¹⁸ O，δ ¹³ C，和有限的氚和碳-14的活动）。大约一半的油井对达科他集团的地层开放。δD是-105.0至-41.7‰（中值-58.2‰）和Δ ¹⁸O为-13.7至-4.4‰（中值为-8.1‰）。总体而言，同位素组成与海拔高度相关，并受水文地质环境影响。十个异常耗竭的水域（最接近火山覆盖的台地）可能代表着海拔更高或冬季偏向的补给，不同的现代降水源或较凉爽的气候补给。通过使用地下水中氯化物浓度的氯化物质量平衡来估算补给量，在海拔2000米以下时，补给量平均为6毫米/年，在海拔2000 m以上时，补给量平均为16毫米/年。ium（不可检测到5.7 units单位）和碳14活性（现代碳分数0.23–1.05）表明，全新世可能以混合物的形式出现于现代水域，冲积通道和其他地表特征促进了补给，其速率可能高于区域性补给。平均。值得注意的是，在这项研究中，同位素贫化的水倾向于不含tri。额外的停留时间示踪剂和季节性降水同位素采样可以解决补给和枯竭水源的问题。