Presentation on theme: "Rocks can fall in love?. * The approximate age of a rock layer or fossil determined by the age of the layers or fossils above or beneath."— Presentation transcript:
Rocks can fall in love?
* The approximate age of a rock layer or fossil determined by the age of the layers or fossils above or beneath.
* A layer of sedimentary rock is older than the layer above it
* Rocks may be folded, tilted, or overturned out of position
* Faults may push rock layers out of position
* Intrusions of magma may cut through rock layers
* Weathering may cause gap in order of layers
* This is the actual age of a substance. * This is measured by using the half life of radioactive elements. * Radioactive elements - These are isotopes (varieties of certain elements containing different masses) of elements whose nucleus is decaying (breaking down, releasing energy and particles at a constant rate).
* EX. Uranium 238 Carbon 14 * - The number stands for the mass of the isotope * - Uranium decays until it reaches lead 206. When an element stops decaying it is considered stable.
* This is the time it takes half the mass of a radioactive isotope to decay into its stable form.