. . . . . "Barite nodules in Devonian shale and mudstone of western Virginia a proposed origin of barite nodules in Devonian shale and mudstone of the Appalachian basin in western Virginia based on physical characteristics of the nodules and on the stratigraphy, paleoenvironment, and geochemistry of the shale and mudstone" . . . . . . . . . "Barite Nodules in Devonian Shale and Mudstone of Western Virginia" . . . . . . . . . . . . . "Barite nodules in Devonian shale and mudstone of western Virginia"@en . "Barite nodules in Devonian shale and mudstone of western Virginia" . "Barytknollen" . . "From 345 to 405 million years ago" . . "Devon" . . . . "Virginia (West)" . .