Paper No. 84
Presentation Time: 9:00 AM-6:00 PM

INDURATED, IRON-RICH LAYERS RELATED TO MICROBES IN CENTRAL MISSISSIPPI SANDSTONE


CUPIL III, Andrew Louis1, GRIFFITH, Collie2, HORNE Jr, Bobby L.3, WILLIAMS, Curlina3, MCGEE Sr, Jervis3, KILPATRICK, Jessica4, WAHIDI, Mahnaz2, COLLINS, Joe D.5 and BAGHAI-RIDING, Nina6, (1)Geoscience, Mississippi State University, Department of Geoscience, Mississippi State, MS 39762, (2)Department of Geosciences, Mississippi State University, Department of Geoscience, Mississippi State, MS 39762, (3)Biology, Delta State University, 1003 West Sunflower Road, Cleveland, MS 38732, (4)Department of Geosciences, Mississippi State University, Department of Geoscience, Starkville, MS 39759, (5)Department of Geosciences, Mississippi State University, P.O. Box 5448, Mississippi State, MS 39762, (6)Biological Sciences, Delta State University, 1003 West Sunflower Road, Cleveland, MS 38732, alc605@msstate.edu

The purpose of the study is to investigate the role of microbes within layers of iron oxide in central Mississippi sandstone along Highway 19 near Philadelphia, MS. The examined cut, approximately 100 ft above the highway, consisted of two exceptionally well-indurated iron layers above a bed of partially to poorly lithified sand. The iron layers were between 18 and 24 cm thick and were red to brown due to iron oxide. The lower 75 ft of outcrop showed erosional features including hoodoos and an approximately two-meter thick section of cross bedding. Four samples were taken along the upper indurated iron layers and from areas of partially lithified sand. They were studied using the SEM, XRD, and Confocal Microscopes at the I2AT Lab at Mississippi State University. The XRD results were inconclusive. Thin sections containing quartz grains and iron oxide were examined under a Nikon E400 POL microscope. SEM and petrographic microscopes revealed evidence of microbial growth such as root hairs, biofilm, and fungal hyphae. In addition, biofilm coats quartz grain surfaces, and numerous microbes occur within voids and fractures of the samples. Mucilage sheets occur on hematite needles forming botryoids. Their core is composed of small spherical organic textures that transition into needle-like crystals. The relationship between microbes and iron oxide is relevant in several applications including remediation techniques, solving oxidation issues, and furthering studies of bacterial growth in areas previously thought to be uninhabitable.