Lecture 16 - Events of the Middle Paleozoic Era
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Historical Geology Lecture 16 The Middle Paleozoic Era Historical Geology Outline I II III Paleozoic Timeline Middle Paleozoic Paleogeography, Climate, and Sea Level Geologic Framework A) B) C) D) Carbonate Sedimentation Organic Reefs Evaporite Basins Clastic Wedges A) B) C) D) Paleogeography and Lithofacies Appalachian (Southern) Margin The Continental Interior Cordilleran (Northern) Margin A) B) C) D) Paleogeography and Lithofacies Kaskaskia Sequence Appalachian (Southern) Margin Cordilleran (Northern) Margin IV V The Silurian Period The Devonian Period Historical Geology The Middle Paleozoic Era Historical Geology Middle Paleozoic Era Paleogeography Ron Blakey http://jan.ucc.nau.edu/~rcb7 Historical Geology Middle Paleozoic Era Climate Average Global Temperature Early Silurian 440 mya Early Devonian 415 mya Historical Geology Middle Paleozoic Sea Level Historical Geology Middle Paleozoic Era Geologic Framework • Carbonate Sedimentation • Organic Reefs • Evaporite Basins • Clastic Wedges Historical Geology Middle Paleozoic Era Geologic Framework - Carbonate Sedimentation • Shallow "Carbonate Factory" • Deep Ocean Calcareous Ooze (since Mesozoic) Carbonate Factory Currents supply nutrients Light for photosynthesis Warm waters Normal salinity Greatest biological productivity <10m Times of high sea level generally allow the factories to be below the depth of the wave base and circulation. This prevents erosion or mixing of the sediments due to normal energy wave abrasion to the carbonate factory and results in a time of high sediment accumulation. Times of low sea level expose the carbonate factory to the zone of wave energy circulation and can even place the factory above the water level. This results in erosion and lithification of the carbonate sediments and can be seen in the sediment record. Historical Geology Middle Paleozoic Era Geologic Framework - Organic Reefs Growth Stages and Architectural Elements through Time Historical Geology Middle Paleozoic Era Geologic Framework - Organic Reefs Windjana Gorge Devonian Australia Historical Geology Era Middle Paleozoic Geologic Framework – Evaporite Basins rock salt NaCl anhydrite CaSO4 rock gypsum CaSO4. H2O Historical Geology Middle Paleozoic Era Geologic Framework - Clastic Wedges Historical Geology Middle Paleozoic Rocks of Laurentia Historical Geology The Silurian Period Panthallasic Ocean Siberia Siberia AntlerArc Paleo-Tethys Ocean Laurentia Rheic Ocean Gondwanaland Ron Blakey http://jan.ucc.nau.edu/~rcb7 Baltica Baltica Gondwanaland Historical Geology Silurian Laurentia • Historical Geology Silurian Laurentia Appalachian (Southern) Margin • Ron Blakey http://jan.ucc.nau.edu/~rcb7 The Continental Interior Basins – Convergence in Iapetus Ocean – Evaporite Deposition – Approach of Avalonia – Niagara Falls – Erosion of Taconic Highlands – Caledonian Orogeny • Cordilleran (Northern) Margin – Convergence and Subduction – Approach of Antler Terrane HistoricalLaurentia Geology Silurian Paleogeography and Lithofacies HistoricalLaurentia Geology Silurian Appalachian Margin • Approach of Avalonia • Erosion of Taconic Highlands • Appalachian Basin Sedimentation • Caledonian Orogeny HistoricalLaurentia Geology Silurian Appalachian Margin - Caledonian Orogeny Historical Laurentia Geology Silurian Continental Interior Basins • Michigan Evaporite Basin Historical Laurentia Geology Silurian Continental Interior Basins • Michigan Evaporite Basin Historical Laurentia Geology Silurian Continental Interior Basins HistoricalLaurentia Geology Silurian Continental Interior Basins - Niagara Falls Historical Geology Silurian Laurentia Cordilleran Margin Ron Blakey http://jan.ucc.nau.edu/~rcb7 Historical Geology The Devonian Period Siberia Panthallasic Ocean Siberia Mongol Arc Kazakh Arc 354 Antler Arc Laurasia Laurasia China fragments Gondwanaland Rheic Ocean 364 370 380 391 Panthallasic Ocean Antler Arc Siberia 400 Siberia Proto-Tethys Ocean 417 Laurasia Gondwanaland Ron Blakey http://jan.ucc.nau.edu/~rcb7 412 Gondwanaland Historical Geology Devonian Laurentia Kaskaskia Transgression ● Oriskany Sandstone Appalachian (Southern) Margin ● Acadian Orogeny ● Catskill Clastic Wedge Ron Blakey http://jan.ucc.nau.edu/~rcb7 Cordilleran (Northern) Margin ● Antler Orogeny Franklin Margin ● Ellsmere Orogeny Historical Geology Devonian Laurentia Paleogeography and Lithofacies Historical Geology Devonian Laurentia Kaskaskia Transgression Historical Geology Devonian Laurentia Kaskaskia Transgression - Oriskany Sandstone initial transgressive deposit over unconformity • very mature sandstone • Historical Geology Devonian Laurentia Appalachian Margin Acadian Orogeny • Catskill Clastic Wedge • Historical Geology Devonian Laurentia Appalachian Margin - Acadian Orogeny Ron Blakey http://jan.ucc.nau.edu/~rcb7 Historical Geology Devonian Laurentia Acadian Orogeny - Old Red Continent Historical Geology Devonian Laurentia Appalachian Margin – Catskill Clastic Wedge Historical Geology Devonian Laurentia Appalachian Margin – Catskill Clastic Wedge Historical Geology Devonian Laurentia Cordilleran Margin Antler Orogeny • Ron Blakey http://jan.ucc.nau.edu/~rcb7 Historical Geology Devonian Laurentia Cordilleran Margin – Antler Orogeny Ron Blakey http://jan.ucc.nau.edu/~rcb7
