Late PaleozoicLate Paleozoic

GeologyGeology

Late PaleozoicLate Paleozoic

• Includes Devonian, Carboniferous, & PermianIncludes Devonian, Carboniferous, & Permian

Late PaleozoicLate PaleozoicIntroductionIntroduction

• Formation of supercontinent - PangaeaFormation of supercontinent - Pangaea

• Continental collisions – mountain buildingContinental collisions – mountain building

– Surrounded by global ocean - PanthalassaSurrounded by global ocean - Panthalassa• Fluctuating sea levelFluctuating sea level

• Various climatic conditions – arid & semiarid climatesVarious climatic conditions – arid & semiarid climates– Due to major continental ice sheets – advance/retreatDue to major continental ice sheets – advance/retreat

– Sedimentary rocks: coal, evaporites, & tillitesSedimentary rocks: coal, evaporites, & tillites

Late Paleozoic PaleogeographyLate Paleozoic PaleogeographyWorld ViewWorld View

• Late DevonianLate Devonian– Baltica meets Laurentia; Iapetus closesBaltica meets Laurentia; Iapetus closes

Caledonian OrogenyCaledonian Orogeny– Laurasia meets GondwanaLaurasia meets Gondwana

Acadian OrogenyAcadian Orogeny– Collision of island arc – western marginCollision of island arc – western margin

Antler OrogenyAntler Orogeny

Late Paleozoic PaleogeographyLate Paleozoic PaleogeographyWorld ViewWorld View

• Carboniferous Carboniferous (known for coal deposits)(known for coal deposits)

– Continents coming togetherContinents coming together Gondwana collides with LaurasiaGondwana collides with Laurasia Siberia meets KazakhstaniaSiberia meets Kazakhstania

– Quachita MountainsQuachita Mountains

Late Paleozoic PaleogeographyLate Paleozoic PaleogeographyWorld ViewWorld View

• Late PermianLate Permian– Assembly of Pangaea completeAssembly of Pangaea complete Surrounded by one large ocean - Surrounded by one large ocean - PanthalassaPanthalassa Bounded by mountainsBounded by mountains Rainshadow – arid climateRainshadow – arid climate

Late PaleozoicLate Paleozoic

• Major events of North AmericaMajor events of North America– Kaskaskia SequenceKaskaskia Sequence– Absaroka SequenceAbsaroka Sequence

Cordilleran AppalachianCraton

LatePaleozoic

EarlyPaleozoic

– Major OrogeniesMajor Orogenies Antler (Corilleran)Antler (Corilleran) Acadian, Quachitan, Alleghenian Acadian, Quachitan, Alleghenian

(Appalachian)(Appalachian)

Paleozoic – Early DevonianPaleozoic – Early DevonianNorth America PaleogeographyNorth America Paleogeography

– Major unconformityMajor unconformity

– Canadian reefsCanadian reefs

– Black shalesBlack shales

• Kaskaskia SequenceKaskaskia Sequence

– Clean SS (Oriskany); Clean SS (Oriskany); some carbonatessome carbonates

Between Tippecanoe Between Tippecanoe and Kaskaskiaand Kaskaskia

Source from eroding Source from eroding AppalachianAppalachian

Barrier reef restricts flow - Barrier reef restricts flow - evaporitesevaporites

Mtn source – Acadian OrogenyMtn source – Acadian Orogeny

Paleozoic – Upper Miss-Lower JurPaleozoic – Upper Miss-Lower JurNorth America PaleogeographyNorth America Paleogeography

• Absaroka SequenceAbsaroka Sequence– UnconformityUnconformity

Miss–Perm boundaryMiss–Perm boundary– CyclothemsCyclothems

Nonmarine-coal-MarineNonmarine-coal-Marine Transgression-RegressionTransgression-Regression

– Ancestral RockiesAncestral Rockies Gondwana collided with Gondwana collided with

LaurasiaLaurasia– Evaporite & Reef DepositionEvaporite & Reef Deposition

Basins within ancestral Basins within ancestral RockiesRockies

Absaroka SequenceAbsaroka SequenceTypical Coal-BearingTypical Coal-Bearing CyclothemCyclothem

• Represent transgression & regression sequencesRepresent transgression & regression sequences• Separated by erosional surfaceSeparated by erosional surface• Represents ideal conditions – not all beds are representedRepresents ideal conditions – not all beds are represented

Coal DevelopmentCoal Development

• Large lowland next to seaLarge lowland next to sea– Slight rise in sea level Slight rise in sea level flood; slight drop flood; slight drop exposure exposure

• Results in alternating marine & nonmarine environmentResults in alternating marine & nonmarine environment• Modern examples: Mississippi Delta, Florida EvergladesModern examples: Mississippi Delta, Florida Everglades

Ancestral RockiesAncestral RockiesSouthwest N. AmericaSouthwest N. America

• Collision of Gondwana and LaurasiaCollision of Gondwana and Laurasia• Fault-bounded uplifted blocksFault-bounded uplifted blocks• Exposure and erosion of pre-Exposure and erosion of pre-ЄЄ basement basement

– Coarse, red arkosic sand & conglomerateCoarse, red arkosic sand & conglomerate

Ancestral RockiesAncestral RockiesEvaporite & Reef DepositsEvaporite & Reef Deposits

• Occurred in various basins bordering ancestral RockiesOccurred in various basins bordering ancestral Rockies• Barrier reef restricted flowBarrier reef restricted flow• Evaporites (central basin); reefs (perimeter)Evaporites (central basin); reefs (perimeter)

Capitan Limestone, Guadalupe MtnsPermian Reef Reconstruction

Late PaleozoicLate PaleozoicOrogeniesOrogenies

• Cordilleran Mobile BeltCordilleran Mobile Belt

• Quachita Mobile BeltQuachita Mobile Belt

• Appalachian Mobile BeltAppalachian Mobile Belt

– Antler OrogenyAntler Orogeny

– Caledonian OrogenyCaledonian Orogeny

– Acadian OrogenyAcadian Orogeny

– The Old Red SandstonesThe Old Red Sandstones

– Alleghenian OrogenyAlleghenian Orogeny

– Quachitan OrogenyQuachitan Orogeny