Flashcards
Phanerozoic [early paleozoic] (21)
Cards in this deck (17)
- 1What is the Phanerozoic Eon?The shortest eon in history
- 2What is the most obvious difference between Precambrian sedimentary rocks and Phanerozoic sedimentary rocks?There is abundant fossils in the Phanerozoic vs. the rare and microscopic fossils of the Precambrian
- 3How is the Precambrian-Cambrian boundary defined?1st appearance of -complex- trace fossils, exemplified by Treptichnus Pedum
- 4How many supercontinent cycles occurred during the Phanerozoic?~1.5 Wilson Cycles
-Panotia > breakup > collisions > Pangaea
-Pangaea > breakup > some collisions > now - 5How has global climate changed during the Phanerozoic?Greenhouse-Icehouse
Ordovician & Jurassic-cretaceous = globally warm to hot
-Pennsylvanian & Late Cenozoic = globally cool (ice ages) - 6How has global sea level changed during the Phanerozoic?Ordovician & Jurassic-Cretaceous = globally high sea levels
Pennsylvanian & late cenozoic = globally low sea levels - 7How has ocean chemistry changed during the Phanerozoic?-The type of CaCO3 that inorganically precipitates from seawater changes through time
-Calcite seas = during high sea level & warm/hot climate & rapid seafloor spreading
-Aragonite seas = during low sea level & cool/cold climate & slow seafloor spreading
-Today: aragonite oolites form
-Ord. & Jur.: calcite oolites formed - 8What is the Paleozoic Era?Means "ancient life"
- 9What is the Early Paleozoic?Cambrian and Ordovician
- 10What were the 4 major continents at this time?Llaurentia
Siberia
Baltica
Gondwana - 11Where were these 4 continents during the Cambrian & Ordovician?Laurentia = On the equator
Siberia = Near the equator
Baltica = High southern latitudes
Gondwana = equatorish? - 12☼What modern landmasses make up Gondwana?☼= South America + Africa + Arabia + Australia + Antarctica + India + Madagascar
- 13What is the Iapetus?An ocean between Laurentia & Baltica
- 14What is Panthalassa?Largest ocean in the Cambrian (most of the northern hemisphere)
- 15What is the Taconic Orogeny? When did it occur? Where did it occur?-A volcanic arc collision
-Volcanic islands crashed into east North America
-1st of 3 mountain building events that formed the Appalachian Mts.
-Middle Ordovician to Silurian - 16Was the western sides of ancient Laurentia passive margins or active margins during the Cambrian & Ordovician?The western side was passive
- 17Do lots of sedimentary rocks get deposited on passive margins?Yes