Role and Evolution of Organic Compounds within the Southeastern United States Kaolin Deposits

There have been numerous studies describing the events that lead to the formation of relatively pure kaolin deposits in Southeastern United States. Yet, many questions still remain pertaining to the distribution, role, and evolution of organic matter during diagenesis and post-depositional maturation. The focus of this study is to provide a better understanding of the organic matter evolution during depositional and post-depositional maturation of the kaolin deposits and how organic matter influences the physical/chemical properties of the kaolin. Samples from open mine faces and 3-inch drill cores were collected from the Buffalo Creek Formation (Cretaceous) and Huber Formation (Marion Member [Paleocene] and Jeffersonville Member [Eocene]) kaolin lenses of Central Georgia. Concentration and various types of organic matter present were characterized using complete combustion CO2 analyzer system and Gas Chromatography/Mass Spectrometry. Organic matter for GC/MS analyses was extracted from kaolin samples via a sequential Soxhlet extraction and HF/HCl complete clay digestion.

Total organic carbon (TOC) concentrations of the Buffalo Creek kaolin are around 0.042 – 0.057 wt.%, with kaolin of the Marion Member containing 0.041 -1.97 wt.% TOC and Jeffersonville Member containing 0.071 – 0.175 wt.% TOC. Lower organic concentrations present in the Buffalo Creek kaolin indicate that this material has undergone a greater degree of post-depositional maturation and oxidative weathering. Whereas the kaolin lenses associated with the Marion and Jeffersonville Members appear not to have undergone as much post-depositional alteration.