List each category of rock and describe how it forms.Explore Student Journal: The Rock Cycle aks on Earth can be classified into three categories based on the way they were formed. Igneous rocks are formed through volcanic action. Sedimentary ks are formed by deposition. Metamorphic rocks are formed when existing rocks undergo a change due to extreme heat and pressure. cks that have a volcanic origin are classified as igneous and form when magma or lava cools and hardens. As the magma or lava cools, crystals begin to im. The size of the crystals depends upon how fast the magma or lava cools. If magma cools quickly, small crystals form and can be observed on the rock iface, such as in basalt, for example. Lava can cool so quickly that crystals do not have time to form at all, such as with obsidian. If magma cools slowly. ger crystals form and can easily be seen on the surface of rock specimens. A commen cxample of igneous rock that exhibits large crystal formation is anite. Then Earth's materials are deposited in layers and pressed together over time, sedimentary rocks form. The formation of sedimentary rock begins with the eposition of sediments. As layers are added, the oldest or lower layers that were deposited first experience increased pressure. The sediments and the paces between them are crushed together in a process called compaction. During the cementation process, the sediments are bound together when a olution fills in around the particles like glue. If the sediments deposited are sand particles, such as in a beach environment, sandstone forms. If the ediments are fine silt or clay-sized particles, commonly called "mud." such as those found in basins worldwide, shale forms. Limestone typically forms from thells and other sediments deposited in ocean environments. A quiet and undisturbed environment will sometimes lead to fossil formation within the layers of sedimentary deposition. Metamorphic rock forms when one type of rock changes into another due to exposure to heat and pressure often coused by movement of material deep beneath Earthis surface. This change to rock appearance and composition takes an extremely long time. Metamorphic rocks are often characterized by wavy layers of mineral crystals or by the presence of unusual minerals. Any rock can become a metamorphic rock. For example, the sedimentary rock shale forms from layers of deposited silt. When exposed to high pressure due to geologic processes, the metamorphic rock slate forms. The sedimentary rock sandstone changes to quartzite when exposed to extreme heat and pressure beneath Earth's surface. Another example of a metamorahic rock is marble. which forms when limestone is exposed to extreme temperatures or pressure. Igneous basalt changes to schist in the metamorphic process. The interesting thing about the metamorphic process is that any rock-igneous, metamorphic, or sedimentary-will change and form new metamorphic rock given enough. time, heat, and/or pressure. The .

1. List each category of rock and describe how it forms.Explore Student Journal: The Rock Cycle aks
on Earth can be classified into three categories based on the way they were formed. Igneous
rocks are formed through volcanic action. Sedimentary ks are formed by deposition. Metamorphic
rocks are formed when existing rocks undergo a change due to extreme heat and pressure. cks
that have a volcanic origin are classified as igneous and form when magma or lava cools and
hardens. As the magma or lava cools, crystals begin to im. The size of the crystals depends upon
how fast the magma or lava cools. If magma cools quickly, small crystals form and can be
observed on the rock iface, such as in basalt, for example. Lava can cool so quickly that crystals
do not have time to form at all, such as with obsidian. If magma cools slowly. ger crystals form and
can easily be seen on the surface of rock specimens. A commen cxample of igneous rock that
exhibits large crystal formation is anite. Then Earth's materials are deposited in layers and
pressed together over time, sedimentary rocks form. The formation of sedimentary rock begins
with the eposition of sediments. As layers are added, the oldest or lower layers that were
deposited first experience increased pressure. The sediments and the paces between them are
crushed together in a process called compaction. During the cementation process, the sediments
are bound together when a olution fills in around the particles like glue. If the sediments deposited
are sand particles, such as in a beach environment, sandstone forms. If the ediments are fine silt
or clay-sized particles, commonly called "mud." such as those found in basins worldwide, shale
forms. Limestone typically forms from thells and other sediments deposited in ocean
environments. A quiet and undisturbed environment will sometimes lead to fossil formation within
the layers of sedimentary deposition. Metamorphic rock forms when one type of rock changes into
another due to exposure to heat and pressure often coused by movement of material deep
beneath Earthis surface. This change to rock appearance and composition takes an extremely
long time. Metamorphic rocks are often characterized by wavy layers of mineral crystals or by the
presence of unusual minerals. Any rock can become a metamorphic rock. For example, the
sedimentary rock shale forms from layers of deposited silt. When exposed to high pressure due to
geologic processes, the metamorphic rock slate forms. The sedimentary rock sandstone changes
to quartzite when exposed to extreme heat and pressure beneath Earth's surface. Another
example of a metamorahic rock is marble. which forms when limestone is exposed to extreme
temperatures or pressure. Igneous basalt changes to schist in the metamorphic process. The
interesting thing about the metamorphic process is that any rock-igneous, metamorphic, or
sedimentary-will change and form new metamorphic rock given enough. time, heat, and/or
pressure. The rock cycle illustrates how rocks move on and under Eartiss crust and change from
one type of rock into another. As rocks move through the rock eycle. their mineral compositions
and physical structures change to reflect the processes under which they are formed. The rock
cycle shows how any rock can undergo change to form any other type of reck. For example, an
igneous rock formed by a volcanic lava llow can crumble to become sand, the sand can be
deposited on a beach and eventually be compacted end cemented to become the sedimentary
rock, sandstone. The sandstone can be buried deep into Earth's crust where extreme pressure
and heat from the overlying layers change the sandstone into a metamorphic rock. Any rock can
be carried so deep that the temperature becomes so great that the rock melts, becomes magma,
and is then ready to move toward the surface to form new igneous rocks. Unlike life cycles, rocks

2. do not have to move through nach stage. An ianeous rock can be changed into a metamorphic
rock, a metamorphic rock can erumble to become a sedimentary rock and sedimentary rocks can
be re-melted to bocome magma. The pathway a rock takes on the rock cycle depends upon the
movements of the rock that place the rock in the position to either ciumble be put under ipeat
pressure, or melt.