1 / 17

Early Paleozoic

Early Paleozoic. Geology. Basic Rules of Geology. Transgression rise in sea level. Regression lower in sea level. Convergence leads to orogeny. Orogeny leads to erosion. Continental Architecture. Stable, immobile part of a continent. Craton. Mobile Belt.

morey
Télécharger la présentation

Early Paleozoic

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Early Paleozoic Geology

  2. Basic Rules of Geology • Transgression • rise in sea level • Regression • lower in sea level • Convergence leads to orogeny • Orogeny leads to erosion

  3. Continental Architecture • Stable, immobile part of a continent • Craton • Mobile Belt • Located along continental margins, receive sediments, and deform during collision • i.e., Franklin, Corilleran, Quachita, Appalachian • Epeiric Seas • Widespread shallow seas that transgress and regress over the continent

  4. Phanerozoic Eon • Phanerozoic – comprises 12% of all geologic time • Paleozoic Era – 6.5% of all geologic time

  5. Paleozoic Eon Introduction • 6 major continents were present – as well as several microcontinents and island arcs • Deposition due to transgressions and regressions • Mountain building (orogeny) due to collision of continents

  6. Early Paleozoic Cordilleran Craton Appalachian Late Paleozoic Early Paleozoic • Major Events of North America • Sauk Sequence • Tippecanoe Sequence • Taconic Orogeny

  7. Paleozoic PaleogeographyGlobal History • Late Cambrian • H2O circulated freely • Polar regions ice free • Epeiric seas • Laurentia, Baltica, Siberia, Kazakhstania, China • Major highlands • Gondwana, Siberia • Late Ordovician • Gondwana moved southward and across the South Pole • Tillites in Sahara Desert • Late Silurian • Laurentia developed active convergent boundary in eastern margin • Baltica moved NW and collided with Laurentia

  8. Paleozoic – Late Cambrian Sauk Sequence • First major transgression • Most of N.A. covered by epeiric seas • N.A. along equator • Evidence of shallow-water deposition • well-sorted, clean sands (ancient shoreline) • Carbonates (stromatolites & ooids)

  9. Paleozoic – Late Cambrian Sauk Sequence • Grand Canyon • Good example of Sauk Sequence • Transgression – “fining upwards” • Tapeats Sandstone • Bright Angel Shale • Mauv Limestone • Time transgressive

  10. Paleozoic – Late OrdovicianTippecanoe Sequence • N.A. in tropical environment • Sauk Sea regressed • Produced unconformity • Boundary between Sauk and Tippecanoe Sequences • Limestone and dolostone experienced rapid erosion • Major transgression • St. Peter SS at base of sequence • Followed by widespread reefs and evaporites • Carbonates Carbonate--corals, bryzoans, dolostone--reefs/evaporites

  11. Paleozoic – Late OrdovicianTippecanoe Sequence • Modern reef structure • Tippecanoe famous for basin rimmed by reefs and evaporites (?) • 30º N&S of equator • Warm, shallow H2O • No sedimentation input • Normal salinity • Evaporites • Evaporation > precipitation • High salinity • Michigan Basin

  12. Paleozoic – Late OrdovicianMichigan Basin • Contradiction • Pinnacle reef • Evaporites • Possible Explanation • Rimmed coral basin • Periodically flooded • Pinnacle reef grew upwards in response to rising sea level • evaporation • Evaporite formation

  13. Paleozoic – Late SilurianAppalachian Mobile Belt • During L. Cambrian & L. Ordovician (Sauk and Tippecanoe Sequences) • Broad, passive margin along eastern edge of Laurentia • Deposition of carbonates overlying shallow-marine seds.

  14. Paleozoic – Late SilurianAppalachian Mobile Belt • Taconic Orogeny • Widening of Iapetus Ocean along divergent boundary • Baltica collided with Laurentia • Iapetus plate subducted beneath Laurentia • Passive  active margin • Results in arc volcanism (mountain-building) • Birth of Appalachian Mts

  15. Late Silurian

  16. Passive margin, L. Proterozoic-L.Ordovician Mid Ordovician Orogeny

  17. Silurian

More Related