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mesozoic geology

Introduction. The Mesozoic began 248 mya and ended 65 myaThree periods - Triassic, Jurassic, Cretaceousbreakup of Pangaea was the major geologic eventtectonism and sedimentation are used to classify the Mesozoic in N. AmericaNote the overlap in three styles of Cordilleran Orogeny. Tectonism and Sedimentation.

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mesozoic geology

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    1: Mesozoic Geology

    2: Introduction The Mesozoic began 248 mya and ended 65 mya Three periods - Triassic, Jurassic, Cretaceous breakup of Pangaea was the major geologic event tectonism and sedimentation are used to classify the Mesozoic in N. America Note the overlap in three styles of Cordilleran Orogeny

    3: Tectonism and Sedimentation

    4: 1. The Breakup of Pangaea The movement of continents during and after the breakup affected global climate and oceanic regimes as well as that of individual continents ocean basins were created or closed before new mountain ranges were built sea-level changes

    5: Pangaea - Early Triassic

    6: Late Triassic – Rifting E Orogeny W

    7: Pangaea – Early Jurassic

    8: E Jurassic – Atlantic Rift Shallow

    9: E Jurassic – Another Look

    10: Pangaea – Jurassic

    11: Late Jurassic – Early Cretaceous

    13: Late K – Epeiric Sea until 70 mya

    14: Mesozoic Global Climates Carbonates (for example the stable isotope index d13C) reveal large concentrations of carbon dioxide present in the Mesozoic atmosphere. This suggests a greenhouse climate. No glaciers, no coal, so CO2 abundant. Greenhouse gasses pass sunlight which hits the land and sea. Re-radiate heat (IR) Greenhouse gasses hold the heat, not lost to space as quickly. Warmer equilibrium.

    15: Global Climates in the Mesozoic

    16: Next: Mesozoic Tectonics NA Cretaceous : global rise in sea level until 75 -70 mya, vast MOR Jurassic: Atlantic opens E, began building the Cordillera W, Gulf of Mexico begins to form and experiences evaporite deposition Late Triassic: Begin rifting in East

    18: Late Triassic: Rifting opens the Atlantic The Newark Supergroup documents the rifting of Pangaea to form the Atlantic Early Triassic saw coarse detrital sediments deposited from the erosion of Appalachian highlands fault-block basins developed as N. America separated from Africa and filled with nonmarine sediment plus dikes and sills eroded to a flat plain by the Cretaceous

    19: Mesozoic rift basins

    20: Structure of the Newark basin

    21: Lake cycles, East Berlin formation

    22: E. Jurassic Gulf Coast Evaporites

    23: Gulf Coastal Region First, as continents separate, restricted basin, thick evaporites formed in the Gulf Normal marine deposition returned to the Gulf by Late Jurassic, with transgressions and regressions thousand of meters of sediments were deposited

    24: Gulf Coast continental margin

    27: Next: Western North America Tectonics Building the western margin of North America and the Cordillera

    28: Western Region Cordilleran Orogeny Laramide - built the present day Rockies K-Tertiary Sevier – J-K thrust faulting to the east Nevadan - Jurassic batholith intrusion in the Sierra Nevada and elsewhere on the western edge

    29: Displaced terranes – Western Cordillera

    30: Western Margin during Orogens

    31: Sierra Nevada Mountains

    32: Mesozoic orogenic events

    33: Buoyant Subduction Laramide Orogeny

    34: Sevier thin-skinned deformation

    35: Sevier thrust belt

    37: Look in detail at western plate margin

    38: Next: Mesozoic Sedimentation on the Craton Cretaceous extensive marine deposition, thin to the east Jurassic clean cross-bedded sandstones marine sediments in the Sundance Sea Triassic shallow-water marine clastics red beds

    39: North America - Triassic

    40: Late Triassic Chinle Fm.

    41: Triassic caliche paleosol- Nova Sc.

    42: North America - Jurassic period

    43: Sedimentation

    44: Jurassic Eolian sandstone

    45: Jurassic Morrison Formation

    46: Fossils of Jurassic dinosaurs

    47: Late Cretaceous really big epeiric sea

    50: Dakota Sandstone

    51: Then, at 75-70 my, Regression

    53: 75 mya Regression

    54: K-T Boundary

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