Late Paleozoic Era

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Late Paleozoic Era

• Chapter 11, part 2

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Last time

• Phanerozoic Eon
• Paleozoic Era
• Cambrian
• Ordovician
• Silurian
• Devonian
• Carboniferous
• Permian

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Late Paleozoic events

• Kaskaskia sequence
• Absaroka sequence
• Mountain building!!

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Signs of mountain building (orogens)

• Volcanic rocks
• Metamorphic rocks
• LOTS of new sedimentary rocks

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Orogenies so far

• Taconic orogeny on east coast in mid-Ordovician
• Iapetus ocean closing

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Devonian period

• Acadian orogeny
• Iapetus continues closing

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Acadian OrogenyClosing of Iapetus Ocean

• Ocean-continent collision first

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Acadian OrogenyClosing of Iapetus Ocean

• With Iapetus closed, forms continent-continent
  collision
• Laurentia and Baltica form Laurasia

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Acadian Orogeny

• Forms Acadian highlands
• Igneous and metamorphic rocks 360-410 Ma

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Devonian

• Acadian orogeny forms Acadian highlands
• Highlands erode

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Devonian

• Detrital sed rocks in deltas
• Catskill delta of New York shed westward

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Devonian

• Detrital sed rocks in deltas
• Catskill delta of New York shed westward

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Devonian

• Old Red Sandstone is sed. shed eastward
• Old Red Sandstone is now in British Isles

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Devonian

• Old Red Sandstone is sed. shed eastward
• Old Red Sandstone is in British Isles

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Orogenies so far

• Appalachian mobile belt
• Taconic
• Ocean-continent collision
• Acadian
• Continent-continent collision

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Orogeny on west coast

• Cordilleran mobile belt
• Passive continental Proterozoic and early
  Paleozoic

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Orogeny on west coast

• mid-Paleozoic, island arc forms off west coast
• Subduction
• Collision between arc and craton
• Antler orogeny
• 1st of many on west coast

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Orogeny on west coast

• mid-Paleozoic, island arc forms off west coast
• Subduction
• Collision between arc and craton
• Antler orogeny
• 1st of many on west coast

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Results of Antler orogeny

• Antler Highlands
• Devonian to Miss.

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Ouachita Mobile belt

• Mississippi to Texas
• Until Mississippian, shallow water sedimentation
• Passive continental margin

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Ouachita Mobile belt

• Mississippian turns active margin

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Ouachita Mobile belt

• Turns to continental collision between Laurasia
  and Gondwana
• Ouachita orogeny

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Ouachita Mobile belt

• Turns to continental collision between Laurasia
  and Gondwana
• Ouachita Mnts. are formed

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Ouachita Mobile belt

• Turns to continental collision between Laurasia
  and Gondwana
• Ouachita Mnts. are formed

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Ouachita orogeny

• Not an average collision collision

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• Marathon Mountains of west Texas also formed in
  Ouachita orogeny

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Ouachita orogeny Mississippian
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Ouachita orogeny Pennsylvanian
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Final orogenies

• Laurasia finishes collision with Gondwana
• Africa collides with southern Europe
• Pangea formed

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Pangea viewed from the South Pole

• Laurasia finishes collision with Gondwana
• Africa collides with southern Europe
• Pangea formed

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Huge collision between Laurasia and Gondwana

• Affects more than mobile belts affects craton
• Pennsylvanian (during Ouachita orogeny)
• Precambrian rocks in central craton brought to
  surface
• Formed ancestral Rockies

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Collision between Laurasia and Gondwana

• Severe affects more than mobile belts
• Affects craton
• Pennsylvanian (during Ouachita orogeny)
• Precambrian rocks in central craton brought to
  surface
• Formed ancestral Rockies

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Collision between Laurasia and Gondwana

• Severe affects more than mobile belts
• Affects craton
• Pennsylvanian (during Ouachita orogeny)
• Precambrian rocks in central craton brought to
  surface
• Formed ancestral Rockies

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Cross-section of Ancestral Rockies in
Pennsylvanian

• Uplift along vertical faults
• Faults 2 km long

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Cross-section of Ancestral Rockies in
Pennsylvanian

• Uplift along vertical faults
• Faults 2 km long

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Pennsylvanian highlands and basins out west

• Uplift new mountains
• Erosion/ sedimentation follows
• Expect to see Pennsylvanian sed rocks

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Erosion of Ancestral Rockies

• Pennsylvanian sedimentary rocksGarden of the
  Gods, Colorado Springs