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The Permo - Triassic Mass Extinction

The Permo - Triassic Mass Extinction. Manuel Queisser. Outline. What happened? Methods of resolution A profound theory: From icehouse to hothouse - The extinction process - Recovery - Summary Discussion. What happened?. Maybe the largest extinction of the Phanerozoic.

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The Permo - Triassic Mass Extinction

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  1. The Permo - Triassic Mass Extinction Manuel Queisser

  2. Outline • What happened? • Methods of resolution • A profound theory: From icehouse to hothouse - The extinction process - Recovery - Summary • Discussion

  3. What happened? • Maybe the largest extinction of the Phanerozoic

  4. What happened? • Maybe the largest extinction of the Phanerozoic • 85% of all marine species and 70% of all terrestrial species died out

  5. What happened? • Maybe the largest extinction of the Phanerozoic • 85% of all marine species and 70% of all terrestrial species died out • E.g. trilobites, rugose corals, pelycosaurs vanished • E.g. brachiopods, ammonoids substantially reduced

  6. What happened? • 320 Ma ago (late Carboniferous) forests developed - CO2 drawdown (level as high as today)

  7. What happened? • 320 Ma ago (late Carboniferous) forests developed - CO2 drawdown (level as high as today) • Pangea assembled - little volcanic CO2 output

  8. What happened? • 320 Ma ago (late Carboniferous) forests developed - CO2 drawdown (level as high as today) • Pangea assembled - little volcanic CO2 output • 4th great glaciation took place

  9. What happened? • 320 Ma ago (late Carboniferous) forests developed - CO2 drawdown (level as high as today) • Pangea assembled - little volcanic CO2 output • 4th great glaciation took place • However, in Permian warming occured

  10. Outline • What happened? • Methods of resolution • A profound theory: From icehouse to hothouse - The extinction process - Recovery - Summary • Discussion

  11. Methods of resolution- Cosmic impact • Consistent with abruptness (< 1Ma)

  12. Methods of resolution- Cosmic impact • Consistent with abruptness (< 1Ma) • Iridium findings not convincing enough

  13. Methods of resolution- Cosmic impact • Consistent with abruptness (< 1Ma) • Iridium findings not convincing enough • Dust layer could have also been created by volcanism

  14. Methods of resolution- Volcanism • Volcanism in Siberia (1-3 Mio km3) produced toxicity and enhanced cooling, then caused greenhouse effect

  15. Methods of resolution- Volcanism • Volcanism in Siberia (1-3 Mio km3) produced toxicity and enhanced cooling, then caused greenhouse effect • Characteristic ash layer in South China (shocked quartz, acidic,…) • Consistent with drop in 13C relative and O18 Meishan section, south China. Bowring et al. 1998

  16. Methods of resolution- Volcanism • Volcanism in Siberia (1-3 Mio km3) produced toxicity and enhanced cooling, then caused greenhouse effect • Characteristic ash layer in South China (shocked quartz, acidic,…) • Consistent with drop in 13C relative and O18 Kidder & Worlsley, 2004

  17. Methods of resolution- Volcanism • critics say this all is not enough to explain the huge 13C drop • Could have never triggered a mass extinction on its own

  18. Methods of resolution- Formation of Pangea • reduced spreading and number of marine provinces (shelves), which regressed species

  19. Methods of resolution- Formation of Pangea • reduced spreading and number of marine provinces (shelves), which regressed species • Explains only marine extinction

  20. Methods of resolution- Formation of Pangea • reduced spreading and number of marine provinces (shelves), which regressed species • Explains only marine extinction • Occurred in early/mid Permian, before mass extinction

  21. Methods of resolution- Salinity drop • First formed by Beurlen in 1956

  22. Methods of resolution- Salinity drop • First formed by Beurlen in 1956 • Evidence that mainly stenohaline organisms suffered

  23. Methods of resolution- Salinity drop • First formed by Beurlen in 1956 • Evidence that mainly stenohaline organisms suffered • Among other reasons: brine-reflux hypothesis:

  24. Methods of resolution- Salinity drop • First formed by Beurlen in 1956 • Evidence that mainly stenohaline organisms suffered • Among other reasons: brine-reflux hypothesis: Evaporation deposited dense salt brines that sank to the ocean bottom and left the surface water “salt free” (drinkable)

  25. Methods of resolution- Salinity drop • First formed by Beurlen in 1956 • Evidence that mainly stenohaline organisms suffered • Among other reasons: brine-reflux hypothesis: Evaporation deposited dense salt brines that sank to the ocean bottom and left the surface water “salt free” (drinkable) • Consistent with a climate warming

  26. Outline • What happened? • Methods of resolution • A profound theory: From icehouse to hothouse - The extinction process - Recovery - Summary • Discussion

  27. From icehouse to hothouse • All this factors alone seem to be too weak to cause such a devastating event

  28. From icehouse to hothouse • All this factors alone seem to be too weak to cause such a devastating event • System of feedbacks: Theory of D. Kidder and Th. Worsley, Ohio State University

  29. Outline • What happened? • Methods of resolution • A profound theory: From icehouse to hothouse - The extinction process - Recovery - Summary • Discussion

  30. From icehouse to hothouse • 320 Ma ago (late Carboniferous) forests developed - CO2 drawdown (level as high as today) • Pangea assembled - little volcanic CO2 output • 4th great glaciation took place

  31. From icehouse to hothouse • 320 Ma ago (late Carboniferous) forests developed - CO2 drawdown (level as high as today) • Pangea assembled - little volcanic CO2 output • 4th great glaciation took place • Cessation of orogeny lowered silicate weathering - kickoff

  32. From icehouse to hothouse • In the mid Permian volcanism in Siberia outpoured CO2 Kidder & Worsley, 2004

  33. From icehouse to hothouse • In the mid Permian volcanism in Siberia outpoured CO2 • Interior of waste Pangea already hot and arid Kidder & Worsley, 2004

  34. From icehouse to hothouse • In the mid Permian volcanism in Siberia outpoured CO2 • Interior of waste Pangea already hot and arid • Now methane hydrates from ocean bottom melted Kidder & Worsley, 2004

  35. From icehouse to hothouse …warming more latent heat transfer warming of high latitudes

  36. From icehouse to hothouse …warming more latent heat transfer warming of high latitudes meridional temp. gradient weakened

  37. From icehouse to hothouse …warming more latent heat transfer warming of high latitudes meridional temp. gradient weakened less advection and further drying of Pangea

  38. From icehouse to hothouse …warming more latent heat transfer warming of high latitudes meridional temp. gradient weakened less advection and further drying of Pangea forests shrink & withdraw to higher latitudes

  39. From icehouse to hothouse …warming more latent heat transfer warming of high latitudes meridional temp. gradient weakened less advection and further drying of Pangea forests shrink & withdraw to higher latitudes CO2 burial and weathering decreases, less nutrients for plankton (positive feedback), dead material oxidized, O2 drawdown

  40. From icehouse to hothouse The Searing of Pangea: Kidder & Worsley, 2004

  41. From icehouse to hothouse • What happened in the oceans?

  42. From icehouse to hothouse • What happened in the oceans? - like in atmosphere O2 content decreased (anoxia)

  43. From icehouse to hothouse • What happened in the oceans? - like in atmosphere O2 content decreased (anoxia) – HOW?

  44. From icehouse to hothouse …warming ice shields melt

  45. From icehouse to hothouse …warming ice shields melt weaken thermohaline circulation

  46. From icehouse to hothouse …warming ice shields melt weaken thermohaline circulation cold, O2 rich bottom water substituted by warmer, saline, anoxic water (WSBW), due to enhanced evaporation, possibly released the methane hydrates (another positive feedback)

  47. From icehouse to hothouse Kidder & Worsley, 2004

  48. From icehouse to hothouse • In late Permian last forests vanished, increased feedbacks (lessened O2) Kidder & Worsley, 2004

  49. From icehouse to hothouse • In late Permian last forests vanished, increased feedbacks (lessened O2) • CO2 level 8 times of today’s level Kidder & Worsley, 2004

  50. From icehouse to hothouse • In late Permian last forests vanished, increased feedbacks (lessened O2) • CO2 level 8 times of today’s level • Average ocean temp. doubled to 30 deg. C in this model Kidder & Worsley, 2004

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