A GROUNDWATER SAPPING LANDSCAPE IN THE FLORIDA PANHANDLE

Drainage networks that have formed by ground-water sapping are develop ed in the highly permeable sands of the Citronelle Formation in the Fl orida Panhandle. The valleys resemble those formed on Hawaii, the Colo rado Plateau and on Mars, but they have developed without significant lithologic controls. Drainage patterns range from trellis to dendritic depending on the effect of beach ridges and relative relief. Many of the drainage networks are not fully developed, and the adjacent upland s have been modified by marine, aeolian, and to a limited extent fluvi al processes. Extension of the networks appears to be episodic, as a r esult of fires, hurricanes, and human activities, which damage or dest roy vegetation.