UNFINISHED BUSINESS – COMPLETING A MENTOR’S SURFICIAL GEOLOGIC MAPS
Two new surficial geologic maps including shallow subsurface geology for the Tupelo and Marietta quadrangles have been compiled. In addition to the field data, USDA Natural Resources Conservation Service (NRCS) Soil Survey data and Mississippi Department of Environmental Quality, Office of Geology (MDEQ) geophysical logs were utilized to complete both quadrangles. Mississippi Department of Transportation borings and NRCS/US Geological Survey LIDAR data were also utilized in completing the Tupelo quadrangle. Neither of those two data sources were available for the Marietta quadrangle. Existing small scale geologic maps were also utilized but were of limited use due to their scale and age. The resulting geologic maps have been digitized and will be delivered to the National Park Service as a portion of the National Park Service Geologic Resources Inventory. The maps will then be published by the MDEQ.
Surficial units mapped on both quads were Cretaceous sediments with Quaternary alluvium and terrace deposits. The Cretaceous units on the Tupelo quadrangle are the Demopolis Formation chalk, and the Coffee Formation sands, including the Tupelo Tongue with the Mooreville Formation chalk in the shallow subsurface. The Cretaceous units on the Marietta quadrangle are the Coffee Formation sands and the Eutaw Formation sands, including the Tombigbee Sand.