Dissolution in a variably confined carbonate platform : effects of allogenic runoff, hydraulic damming of groundwater inputs, and surface–groundwater exchange at the basin scale

Auteur(s) et Affiliation(s)

GULLEY, J.

Michigan Technological Univ., Dept. of Geological and Mining Engineering and Sciences, Houghton, Etats-Unis

MARTIN, J.

Dept. of Geological Sciences, Univ. of Florida, Gainesville, Etats-Unis

SPELLMAN, P.

Michigan Technological Univ., Dept. of Civil and Environmental Engineering, Houghton, Etats-Unis

MOORE, P.

Dept. of Geological Sciences, Univ. of Florida, Gainesville, Etats-Unis

SCREATON, E.

Dept. of Geological Sciences, Univ. of Florida, Gainesville, Etats-Unis

Description :
Gradient reversals cause flood waters to flow from rivers and conduits into the aquifer where they can dissolve limestone. The AA. used legacy data to assess how a gradient of aquifer confinement across the Suwannee River Basin, north-central Florida affected locations, magnitudes and processes of dissolution during 2005–2007, a period with extreme ranges of discharge. During intense rain events, runoff from the confining unit increased river stage above groundwater heads in unconfined portions of the platform, hydraulically damming inputs of groundwater along a 200 km reach of river. Hydraulic damming allowed allogenic runoff to fill the entire river channel and flow into the aquifer via reversing springs. Storage of runoff in the aquifer decreased peak river discharges downstream and contributed to dissolution within the aquifer. Post-depositional porosity in variably confined carbonate platforms should thus be enhanced along rivers that originate on confining units.

Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2013, vol. 38, n°. 14, p. 1700-1713, nombre de pages : 14, Références bibliographiques : 1 p.

Date :
2013

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley

Langue :
Anglais