Title

Assessment of Hydrogeological Controls on Sandhill Wetlands in Covered Karst Using Ground Penetrating Radar

Document Type

Article

Publication Date

3-2017

Keywords

Sandhill Wetland, Karst, West-Central Florida, Ground Penetrating Radar, Borehole Log, Stratigraphic Investigation

Abstract

Sandhill wetlands are one of many types of karst-controlled wetlands and are defined by their isolated position in sandy upland environments. Ground penetrating radar (GPR) data were collected at a sandhill wetland in west-central Florida to resolve the stratigraphy both surrounding the wetland pool and beneath it - defining the stratigraphy allows a better understanding of recharge to the wetland and can aid in guiding wetland preservation. Survey transects were designed to cross through or radiate out from the wetland. The GPR data showed that sands thin or completely pinch out when approaching the wetland pool. Beneath the sand is relatively low permeability silty sand and sandy clay. Slope seepage occurs where these localized aquitards intersect with the ground. Strata gently dip away from the wetland pool. Although bedrock is not recorded in the borehole log, limestone is presumed to exist beneath clay. The bedrock surface is highly irregular and only slightly controls topography. Within the wetland pool, strata are truncated by the dissolution event that created the pool. These findings differ from other wetlands in the area (i.e. marsh wetlands and cypress swamps). The results of this survey, along with water level records, can assist in constructing a hydrogeological framework for the wetland at this site.

Citation / Publisher Attribution

FastTIMES, v. 22, no. 1, p. 43-51.

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