Kinematic constraints on buckling a lithospheric-scale orocline along the northern margin of Gondwana: A geologic synthesis

摘要: Abstract The Paleozoic Variscan orogeny was a large-scale collisional event involving amalgamation of multiple continents and micro-continents. Existing data, suggests oroclinal buckling an originally near-linear convergent margin during the last stages deformation in late Paleozoic. Closure Rheic Ocean resulted E–W shortening (present-day coordinates) Carboniferous, producing near linear N–S trending, east-verging belt. Subsequent Carb-Permian boundary buckling. This late-stage orogenic remains enigmatic part final Pangea amalgamation. present-day arc curvature has inspired many tectonic models, with little agreement between them. While there is general consensus that two separate phases occurred, various models consider caused by: dextral transpression around Gondwana indentor; strike-slip wrench tectonics; or change transport direction due to changing stress fields. More recent explain as orocline, potentially opposite-facing bends, by secondary rotations. Deciphering kinematic history curved orogens difficult, requires establishment phases: initial compressive phase forms relatively belt, second causes vertical-axis rotation limbs. Historically most robust technique accurately quantify vertical axis-rotation paleomagnetic analysis, but recently other types including fracture, geochemical, petrologic, paleo-current calcite twin have been used corroborate A review existing new data from Iberia presented argues for system. Together, these constrain Cantabrian Orocline occurred about 10 Ma latest which agrees well geodynamical structural relate lithospheric delamination Variscan.