Sedimentary Rocks
Explain how a clastic rock is formed then provide one example.
A clastic rock is formed from erosion, compaction, and cementation of clasts.
Sandstone, conglomerate
Define an extrusive igneous rock, then provide an example.
An igneous rock formed outside the Earth's surface with small or nonvisible crystals. Example: rhyolite.
Define a foliated rock, then provide an example.
A metamorphic rock that contains parallel lines of elongated minerals. Example: gneiss.
Name and define the two characteristics that are used to identify rocks.
Composition- what the rock is made of.
Texture- what the rock looks and feels like.
Explain how an organic rock is formed, then provide an example.
An organic rock is formed from the remains of something that was once living.
Conquina and coal
Define an intrusive igneous rock, then provide an example.
An igneous rock formed inside the Earth's surface with large, visible crystals. Example: granite.
Define a non-foliated rock, then provide an example.
A metamorphic rock that contains minerals with random interlocking texture. Example: quartzite
Classify the following rock. Rock A has a high percentage of silica and large crystals. Is this rock intrusive or extrusive? Is this rock basaltic or granitic?
Intrusive, granitic
Explain how a chemical sedimentary rock is formed and then provide an example.
A chemical sedimentary rock is created from precipitation, melting of the minerals which cements the rock sediment together and evaporation of the excess water.
Example: rock salt (halite)
What is volcanic glass? Provide an example.
Volcanic glass is lava that cools too quickly on the Earth's surface and forms without crystals. Sometimes it may contain holes from gas. Examples include pumice and obsidian.
Define metamorphism.
Altering the composition of rock by heat, pressure, or hydrothermal solutions.
Classify the following rock. Rock D is dark colored and has large grains. Is this rock intrusive or extrusive? Is this rock basaltic or granitic?
Intrusive, basaltic
Explain how an igneous rock can be changed into a metamorphic rock.
Igneous rock can be changed into a metamorphic rock by encountering pressure and heat.
How can a metamorphic rock be changed into sedimentary rock?
Metamorphic rock can be changed into sedimentary rock by being melted by magma thus creating an igneous rock, then weathering and depositing created the sedimentary rock.
Classify the following rock. Rock B is fine-grained and light in color. Is this rock intrusive or extrusive? Is this rock basaltic or granitic?
Extrusive, granitic
What is cementation?
Cementation is the process when sediments are glued together by dissolved minerals.
Explain how a sedimentary rock can be changed into an igneous rock.
A sedimentary rock can change to an igneous rock by melting from lava and cooling.
Explain this theory: During the rock cycle matter is neither created nor destroyed. What does this mean?
During the rock cycle matter is simply changed into a different form or version of itself. It never is created as it always comes from a previous form or matter. It is also never destroyed as the rock is eroded or changed form it but it never disappears.
Classifying the following rock. Rock C is from a Hawaiian volcano and contains no crystals. Is this rock intrusive or extrusive? Is this rock basaltic or granite?
Extrusive, basaltic