Biotite phenocryst composition shows that two K-bentonites in the Little Oak limestone (Ordovician) at Old Ragland Quarry, Alabama, are the same structurally repeated tephra layer

Haynes, John T., Melson, William G., and Goggin, Keith E. 1996. "Biotite phenocryst composition shows that two K-bentonites in the Little Oak limestone (Ordovician) at Old Ragland Quarry, Alabama, are the same structurally repeated tephra layer." Southeastern Geology, 36, (2) 85–95.More...