Planet Earth
Outer most layer of Earth
Crust
Another name for deep valleys
trenches
plates collide or rub alongside
How are earthquakes caused
entire (whole) animals have been found preserved-even the soft tissues.
Original Remains
the movement of rock and minerals from one place to another
erosion
Inner most layer of earth
Inner core
another name for mountain chains
ridges
Explain how volcanoes are formed.
subduction when plates push together or pulling apart
Ancient (very old) worm holes, burrows and footprints are sometimes found that have been preserved over time.
Trace Fossils
the wearing away and physical breakdown of rocks
mechanical weathering
Layer under the crust
Mantle
These are found along narrow strips of land
Earthquakes and volcanoes
Explain how mountains are formed
plates push together or rub alongside
Sometimes dead organisms become covered with layers of sediment
Carbon Fossils
when particles of rock that have been eroded away from one place begin to collect or build up in another place
sedimentation
Layer beside inner core
Outer core
large areas have few or none of these
volcanoes
describe theory of sea floor spreading
scientists believe that new surface rock is being formed at the ocean ridges.
Over time, water dissolves the calcium in the bones of dead bodies and leaves silica behind.
Petrified Fossils
when rock is changed by chemical reactions
chemical weathering
pressure and consistency of inner core
increased pressure and rock is solid and hard
This moves very slowly away from ridges and towards the trenches
ocean floor
Describe the theory of continental drift
Scientists believe that the continents used to be connected and have drifted apart over time and continue to drift slowly.
Describe the geologic time scale
A set of dates based on the finding of simple and complex fossils that allows Earth's history to be broken into time periods. A theory from this is that organisms began as simple creatures and evolved to become more complex organisms.
when rock is changed and broken down by the plants and animals living in or on it.
Biological weathering