Quiz 12 Bonus 2 (9:30-9:35 AM)
UNIVERSITY OF SOUTH ALABAMA GY 112: Earth History Lectures 32 and 33: Mesozoic Sedimentation Instructor: Dr. Douglas W. Haywick
Last Time Mesozoic Tectonics A) The Triassic B) The Jurassic C) The Cretaceous (web notes 31)
Mesozoic Tectonics Tectonics in North America during the Mesozoic was dominated by docking events involving terranes. Ultimately, continents grow bigger by scooping up geo-crap in their drift direction (Accretionary tectonics) Sonoman Orogeny
Mesozoic Tectonics Into the Triassic, many more terranes (mostly island arcs) began to be scooped up by North America as it drifted WNW Brooke Range Terrane (Alaska) Stikine Terrane (British Columbia) Sonoma Terrane (Nevada)
Mesozoic Tectonics In the Jurassic, we start to see terranes with mixed lithologies docking with North America (e.g., Klamath Terrane) Major (felsic) intrusions begin
Mesozoic Tectonics In the Cretaceous, more hits and more intrusions. More uplift Wrangellia Terrane docks
What s the Point? The Appalachians and Cordilleran Mountains were both formed via compressional tectonic events. Appalachians formed through collisions with other continents Cordilleran Mts. formed via accretionary tectonics
Today s Agenda Mesozoic Sedimentation A) Triassic Sedimentation (Breakup of Pangaea) B) Jurassic Sedimentation (Birth of the Atlantic Ocean) C) Cretaceous Sedimentation (Creation of the Coastal Plain Province) D) Mesozoic-Cenozoic climate (Greenhouse-Icehouse Earth Transition) (web notes 32)
Mesozoic Paleogeography
Mesozoic Sedimentation Triassic Initial opening of Gulf of Mexico
Mesozoic Sedimentation Triassic Initial opening of Gulf of Mexico
Mesozoic Sedimentation Triassic Initial opening of Gulf of Mexico
Mesozoic Sedimentation Triassic
Mesozoic Paleogeography
Mesozoic Sedimentation Early Jurassic Initial flooding of Gulf of Mexico and Northern Atlantic Ocean
Mesozoic Sedimentation Early Jurassic Initial flooding of Gulf of Mexico and Northern Atlantic Ocean
Mesozoic Sedimentation Late-Triassic/Early Jurassic
Mesozoic Sedimentation Late-Triassic/Early Jurassic
Alabama Mesozoic Stratigraphy
Alabama Mesozoic Stratigraphy Halite (evaporite basin) Great Salt Lake (evaporite basin) http://www.americansouthwest.net/utah/photographs700/salt.jpg
Alabama Mesozoic Stratigraphy Quartz Arenite (beach/desert) Sand dunes in the Gobi Desert
Alabama Mesozoic Stratigraphy Fossil. Limestone & Dolostone (shallow marine with stromatolitic reefs) The Great Barrier Reef http://www.anntorrence.com/blog/at-images/gbr_02.jpg
Mesozoic Sedimentation Mid-Late Jurassic More widespread flooding of Gulf of Mexico and Atlantic Ocean and
Mesozoic Sedimentation Late Jurassic major transgression and flooding of the craton begins Sundance Sea
Mesozoic Sedimentation Late Jurassic major transgression and flooding of the craton begins Sundance Sea Clastic wedges
Mesozoic Sedimentation Sundance Sea Late Jurassic major transgression and flooding of the craton begins Sundance Sea Clastic wedges
Mesozoic Paleogeography
Mesozoic Sedimentation Cretaceous Southern rifting in the Atlantic Ocean Gulf of Mexico stops opening
Mesozoic Sedimentation Cretaceous Southern rifting in the Atlantic Ocean Gulf of Mexico stops opening AL Coastal Plain sedimentation
Mesozoic Sedimentation North South Only key formations are labeled (those discussed in GY 112)
Mesozoic Sedimentation North South Only key formations are labeled (those discussed in GY 112)
Mesozoic Climate High latitudes were warm 50 F / 10 C Dinosaurs near south pole
Mesozoic Climate Period of high sea level Associated with rapid sea floor spreading Long period without reversal Long Cretaceous Normal Chron
Mesozoic Climate Oceans stagnated Epicontinental black muds when seas spilled over Normally thin oxygen poor zone expanded This will change in the early Cenozoic (Late Eocene)
Cenozoic Climate Oxygen isotopes Late Eocene cooling Deep sea foraminifera
Cenozoic Climate Temperature inferred from leaf margins
Cenozoic Climate Paleocene-Middle Eocene: No circumpolar current Late Eocene-today: Circumpolar current Permitted development of glaciers on Antarctica
Cenozoic Climate
Today s Homework 1. Time Chart 3 due Thursday April 28 th 2. Study. Lab Final April 26 th 3. Study. Lecture Final May 4 th 4. Online class evaluation bonus opportunity soon Next Time 1. Cenozoic overview/tectonics
GY 112: Earth History Lectures 32, 33: Mesozoic Sedimentation Instructor: Dr. Doug Haywick dhaywick@southalabama.edu This is a free open access lecture, but not for commercial purposes. For personal use only.