Introduction

The Ozark National Scenic Riverways, one of America's natural resource treasures, contains more than 134 miles of clear spring-fed streams and superb scenery in the Ozarks of southeastern Missouri. It is located in a geologically and hydrogeologically complex area characterized by karstic recharge, major losing streams, and aggrading gravel beds along the Current and Jacks Fork Rivers. The spring system in this area is of world class dimensions and is unparalleled in North America. The region contains the three largest single-conduit springs in the United States, as well as numerous other major springs which issue billions of gallons of water per day. Ground water dye studies have shown conclusively that the recharge areas for these springs can be quite large and encompass source areas that have no obvious relationship to the pattern of surface drainage.
The Ozark National Scenic Riverways also lies at the southern end of the Viburnum Trend (Mississippi Valley Type ore deposit), which is the world's most productive lead mining district. The region surrounding the Ozarks National Scenic Riverways has been exploited in the past for mineral resources and still is being explored for new deposits of base-metals. The National Park Service, U.S. Forest Service, and many environmental agencies are extremely interested in knowing how the hydrogeology of this area might affect and be affected by future mining activity.

The primary goal of the Ozark National Scenic Riverways study is to develop a regional hydrogeologic framework. Emphasis is being placed on:

Mapping geologic contacts and structures
Fracture analysis
Karst mapping
Identifying and evaluating recharge areas
Identifying geologic controls on the locations of springs and losing streams
Determining the influence of protruding knobs of Middle Proterozoic volcanic rocks on ground-water flow through the Early Paleozoic carbonate sequences of the region

Detailed mapping of a number of 7.5-minute quadrangles is underway. These, along with existing reconnaissance maps of adjacent areas, will be used to compile 1:100,000 scale regional maps of the Spring Valley, West Plains, and Poplar Bluff map sheets. These will provide a detailed geologic framework for the Current River region.

Contact Project Chief: Richard W. Harrison (rharriso@usgs.gov)
U.S. Geological Survey, 926A National Center, Reston, VA 22092
Maintained by: Kerry Lagueux; klagueux@usgs.gov
Last modified: 11/08/99