Topic 2: Unit-2 Flashcards
LITHOSPHERE -- The rock cycle (26 cards)
The Rock Cycle
is a natural continuous process in which rocks form, break down and re-form over long period times
4 stages of rock formation
- Formation of igneous rock
- Formation of sedimentary rock
- Formation of metamorphic rock
- Formation of magma
What are igneous rocks?
Rocks formed through the cooling and solidification of magma or lava.
What is magma?
Molten rock found beneath the Earth’s surface(Mantle).
What is lava?
Molten rock that has erupted onto the Earth’s surface.
How are intrusive (plutonic) igneous rocks formed?
By the slow cooling of magma beneath the Earth’s surface, resulting in large crystals.
How are extrusive (volcanic) igneous rocks formed?
By the rapid cooling of lava on the Earth’s surface, resulting in small or no crystals.
What are some examples of intrusive igneous rocks?
Granite, diorite, and gabbro.
What are sedimentary rocks?
Rocks formed from the deposition, compaction, and cementation of sediments.
What are some examples of extrusive igneous rocks?
Basalt, and pumice.
How can igneous rocks transform into other rock types?
Through processes such as weathering, erosion, and metamorphism, which can turn them into sedimentary or metamorphic rocks.
What are sediments?
Small pieces of rocks, minerals, and organic material that are broken down by weathering and erosion.
What are the main processes involved in forming sedimentary rocks?
Weathering, erosion, deposition, compaction, and cementation.
What is weathering?
The process of breaking down rocks into smaller particles by wind, water, temperature changes, or biological activity.
What is erosion?
The process by which weathered rock and soil particles are transported by wind, water, ice, or gravity.
What is deposition?
The process in which sediments are laid down or settled in a new location.
What is compaction?
The process by which sediments are pressed together under their own weight, reducing pore space.
How do sedimentary rocks transform into other rock types?
Through processes such as heat and pressure (metamorphism) or melting (igneous processes).
What is cementation?
The process where dissolved minerals crystallize and glue sediment grains together, forming solid rock.
What are some examples of sedimentary rocks?
- sandstone - formed from sand grains (building material)
- limestone - formed from shells of marine organisms (purify iron and manufacture glass)
- shale - formed from clay particles (source of natural gas and oil)
What are fossils, and how are they related to sedimentary rocks?
Fossils are preserved remains or traces of organisms, commonly found in sedimentary rocks due to the slow accumulation of sediments.
What are metamorphic rocks?
Rocks that have undergone transformation due to intense heat, pressure, or chemically active fluids.
What does the term “metamorphism” mean?
The process of change in the structure and mineral composition of a rock due to heat and pressure.
What are some examples of sedimentary rocks?
- slate - formed from sedimentary rock (shale) and used for roof tiles.
- marble - formed from sedimentary rock (limestone) and used for carving statues
