The Terrane Puzzle: New Perspectives on Paleontology and Stratigraphy from the North American Cordillera
Stratigraphy of the Triassic Martin Bridge Formation, Wallowa terrane: Stratigraphy and depositional setting
Published:July 01, 2008
George D. Stanley, Jr., Christopher A. McRoberts, Michael T. Whalen, 2008. "Stratigraphy of the Triassic Martin Bridge Formation, Wallowa terrane: Stratigraphy and depositional setting", The Terrane Puzzle: New Perspectives on Paleontology and Stratigraphy from the North American Cordillera, Robert B. Blodgett, George D. Stanley, Jr.
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The Upper Triassic (Carnian–Norian) Martin Bridge Formation of northeastern Oregon, southeastern Washington, and western Idaho is characterized by rapidly shifting depositional processes within a tropical volcanic island arc setting. Martin Bridge sequences in the Hells Canyon and northern Wallowa Mountains document shallow-water peritidal evaporitic sediments that are succeeded by deeper and predominantly subtidal deposits. This indicates drowning of the carbonate platform and a transition to deeper-water turbiditic sedimentation before a late Triassic transition into the overlying mid-Norian to Jurassic Hurwal Formation. At the type locality in the southern Wallowa Mountains, dysaerobic shales, carbonate debris sheets, and turbiditic sediments indicate distal...