The Late Paleozoic - the Permo-Carboniferous
• Extensive carbonate platforms - Kaskaskia
• Siliciclastics and cyclic sedimentation - Absaroka
• Global Cooling
• Pangea fully formed
• Major Mountain Building
• Extensive Tropical Forests
• Very diverse marine and terrestrial communities
• Catastrophic End
Late Paleozoic Paleogeography and Geologic History
• Early Carboniferous
• North America flooded by warm shallow sea
– Limestones and evaporites
• Glaciers form on southern continents
– Major regression
Late Paleozoic Paleogeography and Geologic History
• Late Carboniferous
• continents in close proximity begin to collide
• southern continents glaciated
• extensive tropical forests near equator
• burial of organic carbon and mountain building
– low CO2 levels in atmosphere = Ice House World
Late Paleozoic Paleogeography and Geologic History
• Low levels of atmospheric CO2
• Earth’s climate more sensitive to orbital perturbations
– Cooling at high latitudes
• Variations in solar radiation
• Milankovitch Orbital Perturbations
– Waxing and waning of glacial ice
– Sea level change
The Rock Record of Climate Change = Late Carboniferous
• glacial and interglacial periods = high frequency oscillations of S/L
• Cyclothems = transgressive/regressive deposits
• alternating marine and non-marine deposits
The Rock Record of Climate Change = Late Carboniferous
• More marine in Midcontinent, more terrestrial in Appalachian Basin
• More complex than 1 T/R unit
Late Carboniferous Tectonism
• Europe and North Africa Collide with North America
• complex/folded mountain range
• Alleghenian/Hercynian Orogeny
• Largest and last eastern mountain building event
The Permian
• Pangea fully formed
• low global sea level - few continental oceans
• cold/dry climates - severe temperature gradients
• Early = small tropical seas (reefs)
• Late = continental “red beds”
Late Paleozoic Marine Life
• recovery and radiation following a mass extinction
• types of marine organisms similar to Middle Paleozoic
• forms of organisms change in response to rapidly fluctuating environments
and more mobile and efficient predators.
Early Carboniferous
• typical Paleozoic bottom community
– brachiopods, bryozoans, and crinoids
– crinoids very abundant
• fast/agile predators - cephalopods, sharks, and ray-finned fish
Late Carboniferous and Permian Marine Life
• bottom dwelling organisms develop spines = brachiopods
– support on soft substrate and protection
• new/very large “single-celled” organisms = foraminifera
– fusulinids - Late Paleozoic guide fossils
• new reef builders = sponges and algae
Late Paleozoic Land Plants
• The Carboniferous
• extensive tropical forests and wetlands (coal swamps)
• Trees = lycopods
• undergrowth = seed ferns
Permian Plants
• upland forests during Late Carboniferous and most
forests during the Permian = adapted to cold/dry
climates
• gymnosperms - including conifers
Land Plants
• most modern plants first evolved in either the tropical or upland forests
of the Permo-Carboniferous
Animals invade land
• first land animals = insects (flightless bugs and scorpions)
• first land vertebrates = amphibians
• evolved from lobe-finned fish
• innovations that made this possible
– skeletal structure
– Lungs
– eye lids
Late Paleozoic Land Animals
• Late Carboniferous
– insects, amphibians, and reptiles
• Insects become very abundant and very diverse
– flying insects
– some very large
• Amphibians = very diverse
Late Paleozoic Land Animals
• The reptiles evolve - pelycosaurs
– similar in structure to amphibians, but innovative reproduction
– the amniotic egg - allows for a fully terrestrial lifestylePermian Land
Animals
• therapsids = “mammal-like” reptiles
• adapted for harsh environmental conditions
• fur covered and endothermic
• agile and mobile organisms
Permian Mass Extinction
• largest extinction event in the Phanerozoic
• 80% of all life becomes extinct
• two stage event
• colder/dryer climate
• low global sea level
• reduction in shallow marine environments =overcrowding and stress
Late Paleozoic Summary