Abstract: A Hydrogeological Study of the Chicot Aquifer in Lafayette Parish, Louisiana
Timothy W. Duex, Christopher B. Williams
Lafayette Parish uses 35.7 Mgal/d of groundwater that comes primarily from the Chicot Aquifer. In the Lafayette area the Chicot Aquifer consists of approximately 800 feet of Late Pleistocene arenaceous deposits. A major clay bed approximately 100 feet thick divides the aquifer into two informal units: an "Upper Sand Unit" and a "Lower Sand Unit".
This hydrogeological study integrates information from over 40 petroleum well logs, 40 municipal water well logs, several private wells, and several sand-analysis reports to produce a detailed top-of-sand map for both sand units in Lafayette Parish. These surfaces were input with key well logs and modeled with the Stratamodel 3D program to generate three dimensional pictures of resistivity that are called geobodies. These geobodies are an indication of the highest flow locations in the aquifer.
These three dimensional geobodies are significant in identifying possible water-well sites for local municipalities as well as in mapping ancestral deposition patterns. The top of sand map for the "Upper Sand Unit" is also significant in locating areas in the parish where the aquifer is closest to the surface and more rapid vertical migration is possible. This could be important for the siting of Municipal Solid Waste Disposal Facilities.
AAPG Search and Discovery Article #90955©1995 GCAGS 45th Annual Meeting and Gulf Section SEPM, Baton Rouge, Louisiana