Collaborative Research: Investigating Lithologic and Stratigraphic Controls on Hydrogeology in Neogene Strata of the Central High Plains Aquifer

合作研究：研究中部高平原含水层新近纪地层中水文地质的岩性和地层控制Jon Smith，University of堪萨斯，CN-1023285 Michael Petronis，新墨西哥州Highlands University，CN-1023278摘要高平原含水层占美国所有地下水抽取量的近30%。 该含水层正面临越来越大的开发压力，水位出现历史性下降，可能严重影响北美大平原的主要农业生产。本研究的目的是调查地下沉积相，地层格架，和年代地层的新近纪和上覆第四纪单位在中央高原含水层。这些特性控制着含水层的几何形状和水文地质关系，它们来自含水层和隔水层的形成过程和沉积历史。然而，由于含水层的松散和饱和间隔，高平原的高质量地层信息以前是不可能检索的。为此，PI将使用移动的安装在平台上的旋转振动钻机。这种最先进的钻探技术首次提供了一种有效且具有成本效益的收集完整岩心的方法，回收率接近100%。 长的连续岩心，加上岩性，光谱伽马射线和磁性地层岩心测井;稳定同位素化学地层学;和地质年代学的约束所施加的灰岩年代学，光释光（OSL），磁极性研究，和U/Pb测年的新近纪沉积物，将提供关键的时间元素，以限制允许的解释地层对比和水文地层结构。 这项研究将具有全球意义，因为在世界许多地方，源于大陆的新近纪沉积物的异源岩系中的含水层都处于发育压力之下。地下水资源的管理是最有效的，通过使用数值模拟来预测水文地质响应不同的管理策略，这样的模型依赖于准确表征含水层材料和地层框架。

Collaborative Research: Investigating Lithologic and Stratigraphic Controls on Hydrogeology in Neogene Strata of the Central High Plains AquiferJon Smith, University of Kansas, EAR-1023285Michael Petronis, New Mexico Highlands University, EAR-1023278ABSTRACTThe High Plains aquifer accounts for nearly 30% of all groundwater withdrawals in the United States. The aquifer is under increasing developmental stress and experiencing historic declines in water levels that could seriously compromise major agricultural production on the North American Great Plains. The objective of this research is to investigate the subsurface sedimentary facies, stratigraphic framework, and chronostratigraphy of Neogene and overlying Quaternary units in the central High Plains aquifer. These properties control aquifer geometries and hydrogeologic relationships and are derived from the formative processes and depositional histories of water-bearing and confining strata. Quality stratigraphic information from the High Plains, however, has been impossible to retrieve previously due to unconsolidated and saturated intervals of the aquifer. To accomplish this, PIs will use a mobile platform-mounted rotary-vibratory drill rig. This state-of-the-art drilling technology provides, for the first time, an efficient and cost effective means of collecting intact core with nearly 100% recovery. Long continuous cores, coupled with lithologic, spectral gamma-ray, and magnetostratigraphic core logging; stable isotope chemostratigraphy; and geochronologic constraints imposed by tephrochronologic, optically stimulated luminescence (OSL), magnetic polarity studies, and U/Pb dating of Neogene sediments, will provide the critical time element to constrain permissible interpretations of stratigraphic correlation and hydrostratigraphic architectures. This research will have global import because aquifers in heterolithic successions of continentally derived Neogene sediments are under developmental stress in many parts of the world. Management of groundwater resource is achieved most effectively by using numerical modeling to predict hydrogeological response to different management strategies and such models depend on accurate characterization of aquifer materials and their stratigraphic framework.