Abstract

Cenozoic sandstones of the North American interior host the voluminous High Plains Aquifer (HPA) system, which supplies water to c. 30% of all irrigated farmland in the USA. Sandstone bodies in the HPA have eluded characterization because the correlation of discrete sedimentary units between boreholes is exceedingly difficult or even impossible. Our work, however, demonstrates that sandstone-body geometry can be characterized at regional, if not basinal scales, using multi-resolution methods, including remote sensing, outcrop mapping, borehole geophysics, and airborne electromagnetics. These and other scientific advances suggest that the HPA contains a complex assemblage of fluvial sandstone bodies with predictable dimensions. Hydrologic property contrasts between these sandstones and the enclosing, finer-grained strata define a complex arrangement of hydrostratigraphic units. We present this evolving understanding of HPA hydrostratigraphy in a new conceptual model that aids in the understanding of water-supply challenges. We maintain that sustaining well yields and aquifer productivity into the future depends on mapping the architecture of sandstone bodies in the subsurface using advanced techniques.

Thematic collection: This article is part of the Hydrogeology of Sandstone collection available at: https://www.lyellcollection.org/cc/hydrogeology-of-sandstone