WHAT WE DO AND DON'T KNOW ABOUT THE GEOMORPHOLOGIC HISTORY, SURFICIAL GEOLOGY, AND STRATIGRAPHY OF THE EQUUS BEDS AQUIFER IN CENTRAL KANSAS

The Equus Beds represents the easternmost extension of the Neogene Age deposits that are collectively known as the High Plains Aquifer System. No detailed studies of the surficial geology and stratigraphy of the entire Equus Beds have been conducted since the 1940s. The paucity of research efforts in this regard is surprising given that the Equus Beds Aquifer is arguably one of the most important parts of the greater High Plains Aquifer system. It provides drinking water to 15-21% of Kansas' population as well as large volumes of water for agricultural and industrial uses. It is remarkable therefore that our understanding of the geomorphologic history, surficial geology, and stratigraphy is so limited since a greater understanding of the geologic framework of the aquifer would greatly enhance our understanding of its water storage, recharge, and pollution potential characteristics. In this paper I will review the state of our knowledge of the Equus Beds in terms of its surficial geology, stratigraphy, and geomorphic history. I will also discuss obvious and not so obvious problems that must be addressed to improve our interpretations about Equus Beds to better manage this important aquifer.