Sedimentary and Metamorphic Rocks

Let's finish-up talking about rocks.

Sedimentary Rocks:

• form from the weathering and erosion of previous rocks
• the process is- weathering, erosion, deposition, compaction, cementation
• clastic rocks form from fragments of material ex; conglomerate and sandstone
• chemical rocks form from the precipitation of minerals from water (oceans) ex; rock salt and rock gypsum
• fossils are found in sedimentary rocks, the other rock processes would destroy the fossils. Interesting fact, even ripple marks from streams or beaches can be fossilized.

Metamorphic Rocks:

• these rocks form from extreme heat and pressure placed upon pre-existing rocks.
• heat is the primary agent for contact metamorphism, this heat is supplied by nearby magma.
• during metamorphism minerals may recrystallize, crystals can grow larger and the rock will become more compact.
• running water is NOT an agent of metamorphism.

By the way Google Earth has a new version out- download it, pretty cool.