Mountain Shear Zone, Northeastern Wisconsin: A Discrete Ductile Deformation Zone Within the Early Proterozoic Penokean Orogen

摘要

The existence of an extensive belt of well-exposed mylonitic rocks near Mountain, in Oconto County, northeastern Wisconsin, was revealed during reconnaissance geologic mapping in 1980. A detailed geologic map (scale 1:24,000) was prepared during 1985 and 1986, and detailed structural studies were carried out later to determine the nature of the deformation and the sense of displacement. The purpose of this report is to (1) describe the structural features within the shear zone, (2) outline and document the sequence of deformational events, (3) discuss the kinematics, including an analysis of strain, and (4) relate structures within the shear zone to the evolution of the Penokean orogen as a whole.