Geologic Time- Time Scale, Geologic Time Scale – Flashcards

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Why are there divisions in the Geologic Time Chart? (Why do we draw lines between time periods and between eras?)
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Changes in the fossils preserved
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What is the order of time divisions from large to small?
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Eons, Eras, Periods, Epochs
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Which "chunk" of time lasted the longest?
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Precambrian
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What is the oldest known fossil?
Blue-green algae
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Blue-green algae
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What types of fossils, other than blue-green algae, were found at the very end of the Precambrian?
Trilobites and brachiopods
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Trilobites and brachiopods
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What does the word "Paleozoic" mean?
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Old life
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The name for the large number of preserved fossils found immediately after the Precambrian.
Cambrian Explosion
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Cambrian Explosion
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What is the name of the formation that contains Cambrian Explosion fossils? It is in Canada
Burgess Shale formation
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Burgess Shale formation
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The age (time period) of the oldest known fish
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Ordovician
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The age (time period) of the oldest known land plants and animals (scorpions)
Silurian
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Silurian
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The time period known as "The age of the fishes". Also has the oldest known amphibian fossils.
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Devonian
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The time period known for the widespread forests that created vast coal deposits. Also contains the first gymnosperm fossils and the first reptile fossils.
Mississippian & Pennsylvanian
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Mississippian & Pennsylvanian
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The time period known for the first mammal-like reptiles (Dimetredon)
Permian
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Permian
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The age of the largest mass extinction *95% of all life on Earth goes extinct *Cause of the extinction is unknown
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The end of the Paleozoic Era
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"Middle life"
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Mesozoic era
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"Old life"
Paleozoic
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Paleozoic
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The time period when: *the first fossils of dinosaurs appear (small) *the first mammal fossils appear (nocturnal) *gymnosperms (nonflowering plants) common
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Triassic
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"The age of dinosaurs"
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Term for the Jurassic
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The time period when: *the dinosaur fossils are larger *the first fossilized bird is found (archaeopteryx)
Jurassic
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Jurassic
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The time period when: *there are many bird fossils found *the dinosaur fossils are very large *the first angiosperm (flowering plants) fossils are found
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Cretaceous
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The age of a very large mass extinction occurred. *75% of the Earth's species go extinct *The cause of the extinction is well documented
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The end of the Mesozoic era
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"Age of the mammals"
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Term for the Cenozoic era
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The time period when: *mammal, bird and fish fossils are abundant *angiosperms (flowering plants) are abundant *first hominid fossil found ("Lucy")
Tertiary
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Tertiary
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The time period when: *first homo sapien fossils found (human beings) *ice ages occurred (Pleistocene Epoch)
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Quaternary
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How would you describe right now?
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Holocene Epoch of the Quaternary Period of the Cenozoic Era
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A record of the geologic events and life forms in Earth's history.
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Geologic Time Scale
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name for the time in earths early history that accounts for ninety percent of earth's time, but only cellular organisms lived
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Precambrian Era
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it started with the cambrian explosion this is a time when a great number of organisms arose. During this time invertebrates developed along with vertebrates like fishes. Later animals began to reach land. Then the carboniferous period began and reptiles developed. Pangea formed and it ended with a mass extinction. This era lasted from 540 million years ago to 245 million years ago.
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Paleozoic Era
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The period of geologic time, from 250 million to 65 million years ago, during dinosaurs the dominant vertebrates. Ended with extinction of the dinosaurs. Also called Age of Reptiles.
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Mesozoic Era
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The most recent period of geologic time, beginning 65 million years ago, during which mammals became the dominant vertebrates. Also called Age of Mammals.
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Cenozoic Era
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Event in which many types of living things become extinct at the same time. They divide the Geologic Eras
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Mass extinction
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The most massive extinction that has ever occurred, caused by volcanism in Siberia
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Permian extinction
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Lowering of greenhouse gases, cooling, glacial ice and snow reflect heat.
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Snowball Earth
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birds, crocodilians
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Dinosaur descendants
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layered structures produced by the trapping of sediment by blue-green algae
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stromatolites
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blue-green algae that contain chlorophyll and liberate oxygen during photosynthesis
cyanobacteria
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cyanobacteria
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the interval of time since the formaiton of Earth
geologic time
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geologic time
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the division of geologic time into units based on evolutionary events of geologic history
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geologic time scale
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the longest division of geologic time that contains two or more eras
eon
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eon
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a major division of geologic time that contains two or more periods
era
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era
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a division of geologic time that contains two or more epochs
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periods
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a short division of geologic history that contains a notable event
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epoch
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a mineral which contains small traces of uranium, and has been dated back to 4 billion years.
zircon
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zircon
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the process in evolution where the traits of more successful organisms get passed on in favor of those in less successful organisms
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natural selection
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the end of a species
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extinction
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a catastrophic, widespread perturbation in which major groups of species become extinct in a relatively short time compared to normal background extinction
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mass extinction
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