Kansas Geological Survey, Open-File Rept. 90-27
Annual Report, FY89--Page 3 of 10
There are only a few post-1942 studies of older Cretaceous strata in Kansas. The first subsurface studies of Lower Cretaceous strata in Kansas were by Frye and Brazil (1943) and Swineford and Williams (1945). These petrographic studies of well cuttings from Ellis and Russell counties in central Kansas distinguished the different Permian and Cretaceous formations and evaluated their potential as ground-water aquifers or brine-disposal zones. Regional studies of Mesozoic strata in Kansas by Merriam (1957a,b), Lee and Merriam (1954), and Lee (1953), provided more extensive descriptions of lithology distributions in the subsurface.
Franks (1966) described and mapped outcropping Kiowa and Dakota Formations in north-central Kansas. Scott (1967) studied the paleoecological significance of fossils within the Kiowa Formation. Siemers (1971) defined depositional environments within the uppermost part of the Dakota Formation in central Kansas. Franks (1966, 1979, 1980) defined the Longford Member of the Kiowa Formation as a separate lithostratigraphic unit. Scott (1970) examined Lower Cretaceous strata throughout the Western Interior including Kansas. Combining surface and subsurface data, he established faunal zones as a basis for time-rock correlations and described a transgressive-regressive cycle model for deposition.
Smith (1940) and Latta (1941) were some of the earliest investigators to recognize the role of regional flow in the movement of ground water from recharge areas in southeast Colorado to southwest Kansas. More recently the U.S. Geological Survey's CM RASA Program has focused on aspects of regional ground-water flow that affect the Dakota aquifer (Helgeson et al., in press; Jorgensen et al., in press). Using existing data, these reports describe the hydrogeology and water quality of the Dakota aquifer (Great Plains aquifer system) in a regional perspective that covers parts of Kansas, Nebraska, Wyoming, Colorado, New Mexico, and Oklahoma. Similar multi-state regional investigations have been conducted and reported in Belitz (1985), Tait (1986), and Belitz and Bredehoeft (1988). All of these studies have recognized that the Dakota and deeper aquifer systems are regionally subnormally pressured (i.e., fluid pressures significantly less than hydrostatic) due to their relative isolation from the surface and sources of overlying recharge. This relative isolation is attributed to the hydrostratigraphy of the Denver basin and relatively good hydraulic connection of the Dakota aquifer to ground-water-discharge areas eastward of the basin. Recognition of the effect of the regional ground-water-flow system on ground-water geochemistry in the Dakota aquifer has been implied but not strongly emphasized. Previous work in Kansas indicates that the chemical quality of ground-waters in the Dakota is highly variable and is controlled primarily by rock/water interactions and recharge. Early reports by Hay (1890, 1891) and Bailey (1902) document natural discharge of saline waters from the Dakota aquifer in springs, flowing wells and marshes in central Kansas. Work in central Kansas by Frye and Brazil (1943) and Swineford and Williams (1945) show a wide variation in water chemistry vertically and laterally. Additionally, both studies concluded that cross-formational flow across confining layers and along fractures may be a source of saline waters present in the upper part of the Dakota aquifer. Geochemical analyses, isotope work, and hydraulic head gradients indicating a potential for upward flow suggest zones of mixing along fracture zones in central Kansas (Townsend et al., 1988). Work by Latta (1948), Berry and Durum (1952), Hodson (1959), Swineford and Frye (1955), Jordan et al. (1964), and Hargadine et al. (1979) shows that saline waters from the Dakota aquifer aquifer eventually discharge into the Saline, Smoky Hill, Solomon and Republican stream-aquifers systems in central Kansas.