Transcript The Rock Cycle

The Rock Cycle
Ch 4 S 1
Introduction
• Rock: solid mixture of 1+ minerals and
organic mater that occurs naturally
• Rocks are always changing
• Rock Cycle: process in which a new rock
forms from older rock material
The Value of Rock
• Used as
– Tools
– Weapons
– Building Material
Weathering, Erosion, & Deposition
• Weathering: Process in which wind, water,
ice, and heat break down rock
– How sediment is formed
• Erosion: Process in which sediment is
removed from its source
• Deposition: Process in which the sediment
moved by erosion comes to a rest
– It is in this process that sedimentary rock may
be formed
Heat & Pressure
• Sediment + Pressure = Sedimentary Rock
• Sediment + High Temperature & Pressure
= Metamorphic Rock
– Rock can become hot enough to form magma
• Magma Cools = Igneous Rock
How the Cycle Continues
• Uplift: movement that causes rock inside
the Earth to be moved to the surface
– When rock reaches the surface weathering,
erosion, and deposition start
Illustrating the Rock Cycle
Round & Round It Goes
• Each rock type can change into any of the
three types of rock
• Variables such as time, pressure,
temperature, weathering, erosion, and
location determine what type of rock is
formed.
Rock Classification
• Scientists divide rock into 3 classes:
igneous, sedimentary, or metamorphic
• Scientists can classify rocks further by
their texture and composition
Composition
• Composition: the chemical makeup of a
rock (minerals or other material)
• Composition depends on what minerals
the rock contains
Texture
• Texture: quality of the rock based on size,
shape, and position of mineral grains
– Fine grained
– Medium grained
– Coarse grained