Across
- 2. earth's outermost layer,
- 5. rigid,outermost layer of Earth that is about 100km thick, and is composed of the crust and part of the upper mantle
- 6. dating method to determine the order of events and relative age of rocks by examining the position of rocks in a sequence
- 8. core very dense, solid center od the Earth that is made of mostly iron with smaller amounts of oxygen, silicon, sulfur, or nickel
- 9. drift hypothesis proposed by Alfred Wegener that the states that continents have moved slowly to their current locations on Earth
- 11. plastic-like layer below the lithosphere
- 13. fossil formed when an organism is buried, decays, and leaves behind a hollow place in rock
- 14. tectonics theory that Earth's crust and upper mantle are broken into sections that move around on a plastic-like layer of the mantle
- 15. time needed for one half-life the mass of a sample of a radioactive isotope to decay
- 16. decay release of nuclear particles and energy from unstable atomic nuclei
- 17. dating process that uses the properties of atoms in rocks and other objects to determine their exact ages, in years
- 19. largest layer inside Earth, lying directly above the outer core and that is made mostly of silicon, oxygen, magnesium, and iron
- 20. core liquid core that surrounds Earth's solid inner core, and that is made mostly of iron to move back and forth in the same direction the wave is moving
- 21. measure of the energy released by an earthquake
- 22. remains or traces of a once living organism reserved by rock pertified remains/fossils that form when some or all of the original materials that made up the organisms are replaced with minerals
Down
- 1. fossil formed when sediments fill in a mold and harden into rock\
- 2. current cycle of heating, rising, cooling, and sinking that is thought to be the force behind plate tectioncs
- 3. fossil fossil of a species that existed on Earth for only a short time, were abundant, and were widespread geographically
- 4. states that Earth processes happening today are similar to those that happened in the past
- 7. single large landmass made up of all the continents connected together that broke apart 200 million years ago
- 9. film fossil formed when the remains of a once living organism are subjected to heat and pressure, leaving only a thin film of carbon behind
- 10. dating process to determine the absolute ages of rocks by measuring the amounts of parent and daughter materials in a rock
- 12. superposition states that for undisturbed layers of rock, older rocks lie underneath younger and younger rocks
- 18. spreading theory that magma from below Earth's crust is forced upward toward the surface at a mid-ocean ridge, flows from the cracks as the seafloor spreads apart and bcomes solid as it cools, forming new seafloor