STROMATOLITIC FABRICS WITHIN CHERT NODULES IN THE KNOX GROUP OF NORTHWEST GEORGIA

Early diagenetic chert is commonly associated with stromatolitic fabrics and well-preserved individual microfossils in the Precambrian. With the evolution of silica-utilizing organisms in the Neoproterozoic and Cambrian, the process of chert deposition in peritidal environments changed. This change should be reflected in the preservation of microfossils in Neoproterozoic and Cambrian chert deposits. Stromatolites within the Copper Ridge Dolomite of the Knox Group were recently collected near Adairsville, Georgia. These stromatolites, which have only been briefly mentioned in previous literature in Georgia, are associated with large, discontinuous black chert nodules and the stromatolite fabrics include individual layers of black chert. Samples that are predominantly dolomite, tend to preserve columnar stromatolite fabrics with convex laminae. Here we describe the fabrics of these stromatolites and use traditional petrographic techniques to identify possible microfossils observed in the black chert nodules and laminae. We also investigate individual microfossil taphonomy to better describe the preservation of the microfossils present.