EaES 455

1

• EaES 455
• Anton Migurskiy
• Deposition of Transgressive
• Black Shales

2
Black
shales- organic-rich gt1 TOC - fine
grained - dark gray to dark
brown- mature- 80 of hydrocarbons-
unique- greenhouse events- transgressive-
two major widespread deposition D-C J-K-
???????? origin
3
Origin ?

• Many factors involved
  
• Water depth
  - Climate
• Bottom-water environment -
  Primary productivity
• Geography
  - Tectonics
• - Sediment texture
  - Grain size
• Sedimentation rates

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Origin

• ? High primary productivity
• ? Sediment starvation
• ? Anoxia bottom water
• ? Active tectonics (subsidence)
• ? Low latitudes greenhouse events

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1. Sediment starvation
2. Tectonics (subsidence)3-5 High primary
productivity3-5 Anoxia bottom water3-5
Paleoclimate Paleogeography
Wignalls model
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Ettensohn model

• Tectonics (repositories)
• High primary productivity
• 3-4 Sediment starvation
• 3-4 Anoxia bottom water
• 18 Paleoclimate paleogeography

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Seasonal model1.
Dysoxia-anoxia (Tyson)2. Sedimentologic-biogeoch
emical-paleoceanographyc (Murphy et al.)

• 
  Tyson model
• Paleoclimate Paleogeography (seasons)
• Anoxia and Dysoxia bottom water (thermocline)
• 3-5 Sediment starvation
• 3-5 Tectonics
• 3-5 High primary productivity

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Murphy et al. model

• Paleoclimate Paleogeography (seasons)
• 2-3 Sediment starvation
• 2-3 High primary productivity
• Anoxia Dysoxia bottom water
• Tectonics

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Intermittent model (Kenig et al.)

1-2 High primary productivity

1-2
Euxinia bottom water

3-5 Sediment
starvation
3-5
Tectonics

3-5 Paleoclimate
Paleogeography

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Summary

• Primary productivity
• Anoxia
• Sediment starvation
• Tectonics
• Paleoclimate Paleogeography
• Slot
  mashine