GEOCHEMICAL ANALYSIS OF THE MAJOR SPRINGS OF THE OZARK AQUIFER WITHIN THE BIG FOUR REGION OF SOUTH-CENTRAL, MISSOURI

There are scarce data regarding the geochemistry of the four major springs with the largest recharge areas (Big Four Region) in south-central, Missouri. This was made apparent when water erosion undercut a natural tufa dam within the Spring River, Arkansas, causing a hazardous whirlpool within a local kayaking area. The headwaters of the Spring River originate mostly from Mammoth Spring in Fulton County, Arkansas. An examination of satellite imagery revealed over two dozen tufa dams in the first twenty miles of the Spring River. This along with the increasing use of groundwater resources has prompted a state-led investigation into the geochemistry of the major springs of the Ozark Plateau Aquifer.

These current investigations have developed multiple questions for study. (1) What are the geochemical signatures of the major springs of the Ozark Plateau Aquifer? (2) Can the established baseline geochemical dataset along with the mineral chemistry of the tufa suggest implications of possible origins for tufa dam formation? These questions will be answered by analyzing spring water geochemistry in the field for temperature, conductivity, pH, and alkalinity. Spring water samples will be analyzed at the Missouri Department of Natural Resources laboratory for common cations (Ca⁺, Mg⁺, Na⁺, and K⁺) and anions (Cl^-, SO₄^-­­, and NO₄^-).

The four major springs in the Ozarks located in south-central, Missouri and north-central, Arkansas are Hodgson Mill Spring (Ozark County), Mammoth Spring (Fulton County, Arkansas), Greer Spring (Oregon Country), and Big Spring (Carter County). Together these springs discharge approximately > 1200ft­³/s of water from the Ozark Aquifer. The Ozark Plateau Aquifer provides water for public, irrigation, industrial, and domestic use for Missouri residents. If successful, this project will establish the largest geochemical dataset of the major springs within the state of Missouri and provide initial data for future work on tufa dam formations in north-central, Arkansas.