Flashcards in Geology Deck (22):
What's a metamorphic rock?
A sedimentary or igneous rock that has been chemically changed due to heat and/or pressure
What are some uses of metamorphic rocks?
They are good for building, because they are hard and won't get weathered.
What is regional metamorphism?
When rocks change due to tectonic plates moving.
What is contact metamorphism?
When rocks come into contact with hotter materials.
What are minerals and what do they have to do with rocks?
Minerals are pure materials that, when combined, can turn into rocks.
What are the diagnostic tests of minerals?
Streak, hardness, lustre, colour, cleavage.
What is Moh's scale of hardness?
It is a scale used to tell the hardness of minerals. It is listed from numbers 1 to 10. Harder minerals can scratch softer minerals, and this is how we tell how hard a rock is.
What is an igneous rock?
An igneous rock is a rock that has formed from molten materials that have cooled over time.
What is a volcanic/extrusive rock?
It is a rock formed from lava on the Earth's surface. It cools quickly and its crystals are smaller.
What is a plutonic/intrusive igneous rock?
It is a rock that forms from magma which has slowly cooled under the Earth's surface. Its crystals are larger.
How can intrusive rocks become visible?
When the rocks and soil above them wears away.
What is a sedimentary rock?
It is a rock that forms due to pressure in water, and it forms in layers.
How can we find out the speed of the water that a sedimentary rock forms in?
We can tell this by looking at the size of the sediments. Larger sediments were formed in fast water, smaller sediments in slow water.
What is a clastic sedimentary rock?
It is a rock that has formed from broken up and eroded sediments.
What is an organic sedimentary rock?
It is a rock that has formed from parts of previously living organisms.
What is weathering?
It is the breakdown of parent rocks to form sediments.
What is erosion?
It is the removal of weathered materials.
What is deposition?
It is when eroded materials are dropped elsewhere.
What is compaction?
It is when sediments are pressed together. This normally happens in water.
What is cementation?
It is when the pieces of the rock are stuck together.
What is the order of events to form sedimentary rocks?