Chapter 20: Structure of the Heritage Range, Ellsworth Mountains, West Antarctica
Published:January 01, 1992
K. B. Spörli, Campbell Craddock, 1992. "Chapter 20: Structure of the Heritage Range, Ellsworth Mountains, West Antarctica", Geology and Paleontology of the Ellsworth Mountains, West Antarctica, G. F. Webers, C. Craddock, J. F. Splettstoesser
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The main structure of the Heritage Range is an anticlinorium that trends slightly oblique to the range and is flanked on the east by a major synclinorium. This structural pattern is due to probably simultaneous interference folding, with fold axes trending both northwest-southeast and north-south. Second-phase folding occurs only locally, and it is coaxial with the main folds; the folding and cleavage development were followed by the formation of thrust, strike-slip, and normal faults. During the initial faulting the axis of greatest principal stress was perpendicular to the range, but this axis subsequently rotated (counterclockwise) until it was oriented parallel to the tectonic grain. Breccia bodies in Cambrian limestones at the southern end of the range postdate most of the deformation, but they have been affected by late fault movements. All these structures are thought to have formed during the Ellsworth (Gondwanide) Orogeny, probably in early Mesozoic time.