Proterozoic Eon Flashcards
How long did the Proterozoic Eon last
1.958 BY
The Proterozoic Eon accounted for _% of all geologic time
42.5%
What caused Kenorland’s rifting
magma plume rifting
The _ and _cratons began to drift apart by 2.45 Ga
Kola, Karelia
By _ Ga, Kola Craton was located at ~_ degrees and Karelia at ~_ degrees
2.4 Ga, 15 Degrees, 30 Degrees
The breakup of Kenorland was contemporary with what?
Huronian Glaciation
The Huronian Glaciation lasted from _ B.Y to _ B.Y
2.4 B.Y to 2.1 BY
What caused the Huronian Glaciation
The Great Oxygenation Event
What were the effects of the Great Oxygenation Event
- Deposition of Banded Iron Formation
- Huronian Glaciation
How did the Great Oxygenation Event cause an Ice Age?
Methane was the dominant greenhouse gas. However, the abundant oxygen reacted with it to create CO2, a much less effective greenhouse gas, causing an ice age.
Kenorland provided the _ around which the Proterozoic crust accreted
nuclei
What made up Laurentia
North America, Greenland, parts of Northwestern Scotland, parts of Baltic Shield of Scandinavia
Continent forming includes:
- Amalgamation of Cratons
- Accretion of Volcanic Arcs and Oceanic Terranes
- Extensive Plutonism, Metamorphism, and Volcanism
Oldest and Longest Ice Age (300 Million Years)
Huronian Glaciation
The Huronian Glaciation is also called as?
Snowball Earth Episode 1
What kind of organisms existed during the Huronian Glaciation?
Unicellular Organisms
True or False
The Great oxygenation event caused the first mass extinction on Earth.
True
The most famous rock of the Proterozoic Eon.
Banded Iron Formation
Are distinctive units of sedimentary rock that are
consists of repeated, thin layers (a few millimeters to a few centimeters in thickness) of silver to black iron oxides, either magnetite (Fe3O4) or hematite (Fe2O3), alternating with bands of iron-poor shales and cherts, often red in color, of similar thickness, and containing microbands (sub-millimeter) of iron oxides.
Banded Iron Formations
When the Cyanobacteria flourished, minerals and other sinks became saturated. It built up in the water, in the air . To the other bacteria living in the ocean—anaerobic bacteria, remember—oxygen was toxic. The cyanobacteria were literally respiring poison. Why did this event happen.
They could no longer absorb the oxygen being produced.
What triggered the Huronian Glaciation?
Drop in levels of greenhouse gases such as Methane (CH₄) and Carbon Dioxide (CO₂), which keeps the planet warm.
A landmass made up of what are now
North America, Greenland, parts of
northwestern Scotland, and perhaps some of
the Baltic shield of Scandinavia.
Laurentia
Delete card
True or False
The Paleoproterozoic History of Laurentia is not related to the Wilson Cycle.
False, it is also related.