The Mineralogy And Stratigraphic Setting Of The Rocklandian (Upper Ordovician) Deicke And Millbrig K Bentonite Beds Along The Cincinnati Arch And In The Southern Valley And Ridge. Open Access Deposited
Downloadable ContentDownload PDF
Date Modified: 03/26/2018
Petrographic study of the Deicke and Millbrig K-benonite beds (altered volcanic ash) of Rocklandian age has revealed that they can be distinguished by their non-clay mineralogy. The Deicke phenocryst assemblage is primarily labradorite, Fe-Ti oxides, apatite, and zircon, while the Millbrig assemblage is primarily andesine, quartz, biotite, apatite, and zircon. The Deicke is altered dacitic ash, while the Millbrig is altered rhyodacitic ash.
Permanent link to this page: https://scholar.uc.edu/show/cn69m4153