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16 Cards in this Set
- Front
- Back
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General |
8 planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Four inner terrestrial planets Four outer jovian planets Asteroid belt composed of millions of rocky bodies. Kuiper belt composed of icy bodies beyond neptune. |
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Terrestrial planets |
Similar internal structure-Crust, mantle and core. Fixed topographical features. Composed of silicate rocks. Contain secondary atmospheres. Mercury, venus, earth, mars |
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The moon |
Lunar Maria: Dark in colour and made of basalt. Flat with few craters. Lunar highlands: Lighter made of onorthosite. Heavy cratering. |
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Random facts |
Olympus mons=largest volcano in solar system on mars. Noachian epoch=first several hundred years of the solar system. |
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Birth of solar system |
4.55 Ga old Nebula composed of mainly hydrogen and helium. Dense gas cloud contracts due to gravity. Causes temp to rise and nebula to spin. Clous flattens due to centrifugal forces to form a protoplanetary disc. Pressure and temp become high enough for nuclear fusion, creating helium, the sun is born. Cloud cools enough to allow solid particles to condense. Condensed materials accrete to form planets and their moons. |
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Meteorites |
Fragments of rock and/or metal that fall to earth from space. Come from asteroid belt. Stony: Most falls. Composed of silicate minerals. Similar in composition to earths mantle. Carbonaceous chondrites: Represent composition of original sun material. Iron: Small amount of falls. FE-NI Similar to earths core. |
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Evidence for meteorites |
Impact crater. Iridium anomaly. Shocked minerals. Impact melts (Tektites). |
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Radiometric dating |
Isotopes are atoms with same atomic number but different mass number. Unstable and decay over time. The rate of decay is constant. Half-life is the time taken for half the unstable parent isotope to decay and form daughter products. |
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Crust |
Continental crust: Density= 2.7g/cm cubed. Thickness=35Km on average. Age: 0-4 billion years. Silicic. Oceanic crust: Density=3g/cm cubed Thickness=6-7Km Age=200 million years Mafic Rich in Mg and Fe |
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Upper Mantle |
Lithosphere: Ultramafic Crust+upper mantle Rigid Brittle Olivine Asthenoshere: Remainder of upper mantle 100-670 Km Ultramafic Upper Asthenoshere=low velocity zone. Rheid Peridotite |
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Lower mantle |
Solid Similar in composition to stony meteorite. 670-2900Km Convection currents originate from core-mantle boundary. |
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Core |
Outer: Liquid Fe-Ni 2900-5150Km Source of magnetic field. Inner: Solid Fe-Ni 5150-6371Km |
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Discontinuity |
A boundary between the layers of the earth where the composition and/or state changes. Moho=crust and mantle Gutenberg=mantle and core Lehmann= inner core and outer core |
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Direct Evidence |
Mines and boreholes: Directly examine rocks below earths surface. Only reach so far because pressure and temp increase. Kimerlites: Volcanic rocks that occur occur in earth's crust in vertical structures called kimberlite pipes. Carry diomonds and mantle xenoliths to earth's surface. Xenoliths: As magma travels through the mantle, bits of rock may fall into the magma and eventually get carried to the surface. Evidence for mantle composition. Ophiolites: Sections of oceanic crust and upper mantle that have been obducted onto land land are called ophiolites. |
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Rocks |
Rapid cooling=basalt Medium cooling=dolerite Slow cooling=gabbro |
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Indirect evidence:Waves |
Seismic waves: Body waves: P waves: Compressional waves Travel fastest Travel through all mediums S waves: Shear waves Slower and arrive second Stopped by liquids Surface waves: L waves: Long wavelength Last to arrive. Seismic waves reflect and refract at discontinuities and travel and different speeds through the material. (faster if rock is more rigid and more incompressible). Shadow zones: P wave=103°-143° S waves=103°-103° |
