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38 Cards in this Set
- Front
- Back
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How old is the earth |
Approx 4.65 billion years |
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Different time periods |
Eras, period, epoches |
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Geological time scale |
Cenozoic, mesozoic, palaeozoic, precambrian time |
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Order of time periods |
Era -> periods -> epochs |
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Cenozoic era time |
65 myrs |
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Mesozoic era time |
250 myrs |
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Palaeozoic era time |
570 myrs |
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Precambrian time |
4.65 byrs |
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Today's time period |
Cenozoic era, quaternary period, Holocene epoch but maybe be living in anthropocentric epoch |
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Epoch |
Holocene epoch started 10000 years bp to present day. Anthropocene epoch more about humans than ice sheets |
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Anthropocene time |
First atomic bomb new Mexico usa July 21 1945 5:28am |
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KT |
Thin layer of rock, iridium KT comes from meteorites |
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Structure of the earth |
1. Inner core 2. Outer core 3. Mantle 4. Crust |
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Magnetic field |
The inner and outer core are rich in iron, because the iron-rich outer core can flow the earth has a magnetic field |
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The crust |
Oceanic and continental |
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Oceanic crust |
Thinner 7-10km Dark in colour More dense (3.0g/cm3) |
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Continental crust |
25-70km Light/white in colour Less dense (2.7g/cm3) |
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Lithosphere |
Solid surface layer that includes the crust and the upper mantle. |
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Asthenosphere |
Semi liquid layer beneath the lithosphere |
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Rock types |
1. Igneous rock 2. Sedimentary rocks 3. Metamorphic rocks |
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Rock |
A rock is an aggregate of one or more minerals. Three types based on how they form. |
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Igneous rock |
Form when melted rock - lava or magma - cools and solidifies. Also form when solid rock fragments (ash) is ejected by a volcano |
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Sedimentary rock |
Form when a preexisting rock is subjected to weathering and the resulted sediment is eroded, transported, deposited, and lithified. These rocks may also form when new minerals precipitate from elements or molecules in solution (salt) |
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Weathering |
The disintegration of a rock or mineral by physical and chemical processes |
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Erosion |
The way in which sediment is set in motion |
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Transport |
The way sediment moves once it is in motion |
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Deposition |
The way sediment stops moving |
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Lithification |
The transformation of loose sediment (sand) into solid rock (sandstone) |
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Metamorphic rock |
Form when a preexisting rock is subjected to heat and pressure. There is no significant melting. |
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Plate tectonics |
Theory that the earth's crust is separated in pieces or plates and that these plates move |
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Plate margins |
Convergent Divergent Transform |
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Convergent |
Where plates collide |
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Cont vs ocean |
The oceanic plate us pushed user or subducted under because it is denser |
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Cont vs cont |
No subduction No melting No volcanism Becomes a mountain |
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Ocean vs ocean |
One slides under other |
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Divergent |
Where plates pull apart from one another |
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Transform |
Where two plates move past one another in a side by side motion. No subduction No melting No volcanism Limited mountain building |
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Hot spots |
These are areas of volcanism at the earth's surface because of increased heat flow from the mantle beneath. Hot spots are not found at plate margins. |
