Three-dimensional model of a mushwad and its implications for the evolution of an Appalachian subrecess in northwestern Georgia
Published:August 12, 2020
Brian S. Cook*, William A. Thomas, 2020. "Three-dimensional model of a mushwad and its implications for the evolution of an Appalachian subrecess in northwestern Georgia", The Appalachian Geology of John M. Dennison: Rocks, People, and a Few Good Restaurants along the Way, Katharine Lee Avary, Kenneth O. Hasson, Richard J. Diecchio
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In a well-defined subrecess in the Appalachian thrust belt in northwestern Georgia, two distinct fold trains intersect at ~50° in the down-plunge depression of the Floyd synclinorium. A mushwad (ductile duplex) of tectonically thickened weak-layer rocks (primarily the shale-dominated Cambrian Conasauga Formation) filled the space beneath folds and faults of the overlying Cambrian–Ordovician regional stiff layer (mushwad roof). Measurements of the mushwad thickness from balanced cross sections provide the basis for three-dimensional (3-D) models. Tectonically thickened weak-layer shales in a model using a simple line-length balance of the stiff layer have a volume of ~64% of the volume in...
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The Appalachian Geology of John M. Dennison: Rocks, People, and a Few Good Restaurants along the Way
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Dr. John M. Dennison spent his career studying the Appalachians; teaching and mentoring his students and professional colleagues; publishing papers; leading field trips; and presenting ideas at regional, national, and international conferences. This volume is a collection of papers contributed by former students and colleagues to honor his memory. Topics include stratigraphy and paleontology ranging in age from Ordovician to Mississippian in Kentucky, New York, Tennessee, Virginia, and West Virginia; Devonian airfall tephras throughout the eastern United States; a Devonian lonestone; a Middle Eocene bentonite in North Carolina and its relationship to a volcanic swarm in western Virginia; and a 3D model of a ductile duplex in northwestern Georgia. The stratigraphic and geologic diversity of the papers reflects Dennison's many interests and collaborative relationships.