Ordovician

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EARLY PALEOZOIC LIFE
Ordovician
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EARLY PALEOZOIC LIFE
Silurian
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EARLY PALEOZOIC LIFE
Plants in the Paleozoic
Stromatolites Blue-green algae Abundant in
Cambrian
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EARLY PALEOZOIC LIFE
Plants in the Paleozoic
Green algae Receptaculids Chlorophytes Silurian
to Devonian
Unknown affinity Sunflower coral Not sunflower
or coral
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EARLY PALEOZOIC LIFE
Plants in the Paleozoic
Land Plants Cooksonia Silurian
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EARLY PALEOZOIC LIFE
Mass Extinctions
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EARLY PALEOZOIC LIFE
Mass Extinctions

• Extinction Processes
• Extinction strikes on the land and in the sea.
• On the land, while animals suffer repeatedly,
• plants tend to be highly resistant to mass
  extinctions.
• Preferential disappearance of tropical forms of
  life
• during mass extinctions.
• Tendency of certain groups of animals to
  experience
• them repeatedly (for example, trilobites and
• ammonoids).
• Alleged equal spacing, or periodicity in
  geological time
• (occurring about every 26 million years).

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EARLY PALEOZOIC LIFE
Mass Extinctions
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EARLY PALEOZOIC LIFE
Mass Extinctions
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EARLY PALEOZOIC LIFE
Mass Extinctions
Ordovician Mass Extinction Second most
devastating in earth history Caused by glaciation
and associated lowering of sea level
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EARLY PALEOZOIC LIFE
Mass Extinctions
Devonian Mass Extinction Caused by glaciation or
meteorite impact
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EARLY PALEOZOIC LIFE
Mass Extinctions
Permian Mass Extinction 90-95 of marine species
became extinct in the Permian Caused by formation
of Pangea, glaciation, volcanic eruptions
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EARLY PALEOZOIC LIFE
Mass Extinctions
Triassic Mass Extinction 25 of all families
became extinct at end of Triassic Caused by
climate change (increase in rainfall)?
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EARLY PALEOZOIC LIFE
Mass Extinctions
Cretaceous-Tertiary (K-T) Mass Extinction 85 of
all species died in the K-T extinction Caused by
meteorite impact and/or volcanic eruptions
15

THE DEVONIAN
The Age of Fishes Named for outcrops near
Devonshire, England Named by Sedgewick and
Murchison in 1839 prior to bitter
arguments Includes the Old Red Sandstone of
Scotland and Wales
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THE DEVONIAN
The Age of Fishes
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THE DEVONIAN
18
THE DEVONIAN
Kaskaskia Sequence Began in Devonian and
continued to the end of the Mississippian Craton
again flooded
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THE DEVONIAN
Kaskaskia Sequence Began with deposition of
clean quartz sand Initial deposit of
transgressing sea Oriskany Sandstone
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THE DEVONIAN
Kaskaskia Sequence Oriskany Sandstone Some heavy
minerals Indicate source area Sandstone
followed by Limestones Salts and
gypsum Shales
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THE DEVONIAN
Acadian Orogeny
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THE DEVONIAN
Devonian Paleogeography
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THE DEVONIAN
Devonian Paleogeography
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THE DEVONIAN
Impact of Avalonian Terrane Thick folded
sequence of turbidites Intruded with rhyolites
and granites Destroyed the marine depositional
basin off eastern US coast
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THE DEVONIAN
Impact of Avalonian Terrane Nonmarine clastics
shed to west
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THE DEVONIAN
Impact of Avalonian Terrane Changes from
conglomerate to shale going east to west
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THE DEVONIAN
Impact of Avalonian Terrane
Catskill Clastic Wedge
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THE DEVONIAN
Impact of Avalonian Terrane
Catskill Clastic Wedge
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THE DEVONIAN
Impact of Avalonian Terrane
Catskill Clastic Wedge Nonmarine rocks red
color Braided or meandering streams
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THE DEVONIAN
Impact of Avalonian Terrane
Catskill Clastic Wedge
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THE DEVONIAN
Impact of Avalonian Terrane
Catskill Clastic Wedge
First forests Gilboa, NY
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THE DEVONIAN
Impact of Avalonian Terrane
Gilboa, NY Fossils
Winifred Goldring NY State Paleontologist First
woman to hold title
Aneurophyton (foliage) Eospermatopteris (tree)
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THE DEVONIAN
Impact of Avalonian Terrane
Gilboa, NY Reconstruction of Forest
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THE DEVONIAN
Europe Old Red Sandstone Equivalent to Catskill
Clastic Wedge
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THE DEVONIAN
Acadian shales Chattanooga Shale Few fossils,
stagnant anoxic water High organic content,
black, phytoplankton bloom
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THE DEVONIAN
Western US Williston Basin Reefs developed Salt
and gypsum Extensive oil reserves
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THE DEVONIAN
Western US Antler Orogeny Late Devonian to
Pennsylvanian Began with subduction on west coast
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THE DEVONIAN
Western US Antler Orogeny Late Devonian to
Pennsylvanian Convergence of volcanic island arc
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THE DEVONIAN
Western US Antler Orogeny Convergence of volcanic
island arc
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THE DEVONIAN
Devonian Paleogeography