Evidence of Earth’s History 8.E.2.1 and 8.E.2.2

Deposition is the process that A. dissolves sediment Warm up Deposition is the process that A. dissolves sediment B. breaks down rock C. drops sediment D. moves rock particles

QUIZ 1. This type of rock has layers. 2. This type of rock forms from magma or lava. 3. This type of rock changes from an existing rock. 4. Igneous rock from _______ has large grains 5. Igneous rock from _______ has small grains.

Group Activity

Evidence of Earth’s History Just as earth’s lithosphere has changed over time so has earth’s climate and life forms Fossils, ice cores and rock provide evidence about changes Geology is the study of earth’s history

Fossils Fossils- preserved remains or evidence of organisms that once lived Formed after the organism died and was covered by sediment If the organism decays it leaves a mold- a hollow space in the rock that shows the shape of the organism Hard parts( teeth, bones) are preserved Behaviors or actions can be preserved such as footprints

Fossils

Ice cores Ice core- a cylinder of ice removed from an ice sheet Ice builds up in layers like sediment in areas where ice doesn’t melt in the summer The texture of the snow is different in the winter and summer Air bubbles in the ice provide evidence about the atmosphere ( dust, ash and carbon dioxide)

Rocks Radioactive dating- measures the age of material by measuring the amount of radioactive material The decay process happens at predictable rates For example- uranium decays into lead