|Brahana, John - UNIVERSITY OF ARKANSAS|
|Kresse, Timothy - ARKANSAS DEPT ENVIRONMENT|
|Murdoch, John - UNIVERSITY OF ARKANSAS|
Submitted to: Geological Society of America Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 4, 2000
Publication Date: N/A
Technical Abstract: More than ninety percent of the springs in northwestern Arkansas that have discharges of 0.15 m**3/sec or greater lie within 300 meters of regional faults and lineaments. The hydrogeologic importance of these structural features, which are systematic, brittle fractures that occur in near-horizontally, nonhomogeneous, anisotropic carbonate rocks, is that they serve as the primary vertical avenues of interaquifer flow. Mixing of waters from multiple shallow and deep flow sources is the rule rather than the exception at major springs, and assessment of water-quality changes provides a valuable constraint for conceptual models. Recent studies monitoring time-variable discharge and selected water-quality parameters in springs, wells, and surface drainages are being measured in six ground-water basins at the Savoy Experimental Watershed (SEW), Northwest Arkansas. Continuous sampling indicates that timing of sample collection can be critical at springs or wells affected by these structural controls. In addition to documenting system variability and helping formulate sampling rationale, preliminary data from continuous monitors and discrete hydrologic event sampling is providing valuable information on budget contributions from these complex ground-water systems.