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Earth History GEOL 2110. The Paleozoic Era Carboniferous and the Permian Periods in North America. Major Concepts. Carbonate deposition dominant in the Silurian and Devonian, persisted into the early Carboniferous (the Mississippian period).
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Earth History GEOL 2110 The Paleozoic Era Carboniferous and the Permian Periods in North America
Major Concepts • Carbonate deposition dominant in the Silurian and Devonian, persisted into the early Carboniferous (the Mississippian period). • After a major regression and subsequent transgression marking the Mississippian-Pennsylvanian break in North America, the Absaroka sequence was dominated by clastic sediments and great accumulations of land-based organic material creating coal seams. • This change in sedimentation, which persisted into the Permian, was triggered by creation of the final orogenic event of the Appalachian mobile belt caused by the collision of southeastern North America with Africa and South America and the creation of the large continental land mass ever on Earth - Pangea
Mississippian DepositsMore Limestone Chockful O’ Crinoids Madison LS, MT Redwall LS, AZ Pahasapa LS, SD
Late Mississippian Regression Immature clastic sediment appear in Eastern NA deposits Sourced from deeper erosion of rejuvenated Caledonian and Acadian Mts More Unconformities developed on warped craton highs
Pennsylvanian DepositsClastic Sedimentation Dominates (+Coal)
Pennsylvanian DepositsCyclothems – Trangressive Cycles Limestone Coal Organic Shale TRANSGRESSION Shale Sandstone Illinois Basin Cyclothem
Pennsylvanian DepositsOver 100 Cycles in 100 million years! • Cause of Cycles • Rapid sea level changes due to Gondwanaland glaciation • Spasmodic tectonic up-down oscillations • Cyclic climate change affecting erosion and sedimentation
Pennsylvanian Coal DepositsSubtropical Rain Forests Peat Anthracite Everglades Bituminous Coal AnthraciteCoal
Permian Deposits Craton Tilts West / Seas Retreat / Climate Dries
Late Paleozoic Strata of the Grand Canyon Kls Tf Css HSh Sgp
Permian Climate Dries In the Rain Shadow of the Appalachians
Continent-Continent CollisionMonster Thrust Faulting 1950’s Interpretation 1980 ~260 Km Displacement
Summary of Paleozoic Tectonics Acadian/Caledonian Appalachian/Hercynian Gondwanaland Taconian North American Paleozoic Orogenies
Next Lecture • The Paleozoic Era • Geological History of Gondwanaland and Late Paleozoic Life • Mid-term on Friday!! • Chapters 8-13