There are about 20 rock-forming minerals that make up most of
Earth's crust.
Granite can be described as a
Light-colored rock with high silica content.
A metamorphic forms when
Heat and pressure change an existing rock.
Texture
Describes how a rock's surface looks and feels.
Color alone does not provide enough information
To identify a rock.
To study a rock sample,
Geologists observe the rock's a mineral composition,color,and texture.
The way in which each of three major groups
Of rocks forms is different.
A rock's grains give the rock the
Texture.
Rock's that have
Large grains you can easily see are described as coarse grained.
Rock's that are
Banded have grains that lie in a pattern of flat layers or form swirls.
What characteristics do geologists observe when studying a rock sample?
They look for the rock's mineral composition,color, and texture.
Name the three major groups of rock's and describe how each forms.
Igneous rock forms when magma or lava cools. sedimentary rock forms when small particles of rock's or the remains of plants and animals are pressed and cemented together. Metamorphic rock forms when a rock is changed by heat and pressure,or by chemical reactions.
The series of processes that slowly change Earths rock's from one kind to another is called the
Rock cycle.
Plate movements helping to form
Magma,the source of igneous rocks.
Deep beneath the surface,
Heat and pressure can change sedimentary rock to metamorphic rock.
Through processes of,
Melting metamorphic rock can become magma.
Sediment piles up on the ocean floor through the the process of deposition.
on the ocean floor through the the process of deposition.
The process that breaks down granite into sedimentary is
Weathering.
There are many pathways by which rock's move through
The rock cycle.
As rock's move through the rock cycle,
Material is not lost or gained.
Forces of the rock cycle operate
Inside Earth and Earth's surface.
The collision of continental plates can push up a mountain range,
After which weathering and erosion begin.
Describe how the granite of a mountain could change first into sandstone and then into quartzite.
As the forces of mountain building slowly push the granite upward, weathering and erosion wear away the granite to form sand. Streams carry the sand to the ocean where layers of sedimentary pile up on the ocean floor. The sediments get compacted and cemented together to form sandstone. If pressure compacts the sandstone particles further and silica replaces the calcite holding the rock together,quartzite will form.
Describe how a collision between continental plates can result in the formation of metamorphic rock.
A collision between continental plates can push rock's down deep beneath the surface. Here, heat and pressure could change the rock's to metamorphic rock.