| Front | Back |
|
Igneous
|
Formed from the hardening of molten rock, magma, lava.
Ex: granite, pumice, basalt, obsidian. |
|
Sedimentary
|
Formed by sedimentation, gradual depositing or small bits of rock or clay. FOSSILS. Shale, sandstone, gypsum, dolomite, coal.
|
|
Metamorphic
|
Formed when existing rock material is altered through temperature, pressure, or chemical process. Ex: marble, slate, gneiss, quartzite.
|
|
Age of Earth
|
4.6 billion years old
|
|
Precambrian Eon
|
4.6 billion years ago - 570 million years ago. Before the fossil record began.
|
|
Life on Earth
|
3.5 billion years ago
|