Presentation on theme: "Carbon Dating Used for determining the age of earth materials"— Presentation transcript:
1Carbon Dating Used for determining the age of earth materials Age of rocks, fossilsEvery living organism on Earth has carbonWhen organism dies, carbon remains but begins to break down at a predictable rate- half lifeHalf-life of carbon-14 is 5,730 years
2How old is it?Every 5,730 years the amount of carbon will reduce by half.This means that no matter how old something is, the amount of carbon can get smaller and smaller but never go away.If a fossil of a fish is found and scientists know it originally had 2g of carbon-14 and now only has g, how old is it?
3If carbon is in all living things, it is in rocks and soil- decomposition. Carbon dating is used to help estimate the age of the earthBut the oldest rocks are usually located at the bottom of a rock profile. Why?
4Law of SuperpositionSediments or lava are deposited on top of the existing rocks or soil.Those sediments are compacted to form new rockNew rock on top, old rock at bottom
5Exceptions to the Law of Superposition FaultingNon-depositionIntrusion- injection of lava from the mantleWhich layer is the oldest?Which is the youngest?
6Layers of the Earthinner core - mass of solid iron with a temperature of Fouter core – liquid iron, responsible for our magnetic fieldsmantle - slow moving molten rock or magma, Fcrust - layer from 4-25 miles thick consisting of sand and rock
11Continental vs. Oceanic Plates Continental crust is less dense than oceanic crustWhen continental plate collides with oceanic plate, oceanic will go under the continental and oceanic plate is subducted or recycled back into the mantle.***See Plate Boundaries handout ***
12When Plates CollideConvergent Boundary- two continental plates collide forming mountains- Mt. Everest and Himalayan MtsSubduction Zone- oceanic vs. continental or oceanic vs. oceanic- Ring of Fire, Mt. St. Helens, Mt. Vesuvius
13Pull Apart Divergent Boundary- two plates pull apart Forms Mid-Ocean RidgesMid-Atlantic Ridge-Iceland Volcano
14Sliding Past Each Other Transform Boundary ↑↓- Creates FaultsFaults- cracks in the Earth where plates move past each otherSan Andreas Fault, New Madrid FaultEARTHQUAKES!
15Earthquake! Fault- plate boundary Focus- point inside the earth where earthquake beginsEpicenter- Point on SURFACE where earthquake begins
16Earthquakes Release Energy P-Wave- Primary WaveS-Wave- Secondary WaveSurface waveWaves are longitudinal or transverse
17Long Term Effects of Plate Movement Continental driftSlow and gradual movement of tectonic plates in the same directionAlfred WegenerPangaeaCaused by convection currents in mantle
18Day Night and More Rotation- spinning of Earth on axis Revolution- orbit of Earth around the SunEarth’s axis is tilted 23.5 degreesAltitude, longitude and latitudeDay and NightYearSeasonsDetermines the temp and climate of a region