An Investigation of the Origin and Extent of a Hillslope Wetland, Millsaps College, Jackson, Mississippi

Jeannie R. Bryson and Stan Galicki
Millsaps College, Jackson, Mississippi

The origin and extent of a hillslope wetland was investigated using historical topographic maps and hydrologic data. The area of investigation is situated on a gradual slope yet supports black willow (Salix nigra), soft rush (Juncus effusus), and cattail (Typha latifolia). Hydric soil development has also been documented. The extent and duration of the water table was determined using a network of shallow piezometers and a continuously monitored shallow well. Digital and manual head measurements documented the saturation of the root zone during a 12-month growing season.

Based on successive topographic surveys that were conducted over the past 44 years, the perched water condition appears to be related to the construction of a baseball field in the late 1970's. The hilltop grading of a pre-loess terrace of Pleistocene age facilitates the drainage of water. The pre-loess terrace deposits that were removed during construction of the baseball field were used in re-contouring the slope and fill of a drainage depression that had developed in the underlying Yazoo Clay. The margin of the localized (0.5 hectare) wetland corresponds to the extent of the filled-in drainage.

AAPG Search and Discovery Article #90032©2004 GCAGS 54th Annual Convention, San Antonio, Texas, October 10-12, 2004