Earth Science Final Review Part 2 Flashcards
Where do glaciers form? How do glaciers form?
Form in places that have cold temperatures year-round. The cold keeps fallen show from completely melting and each year the snow that has not melted accumulates in an area called a snowfield. The total thickness of the snow layer increases as the years pass and a glacier begins to form. The weight of the top layers of snow exert enough downward pressure to force the snow below to recrystalize into ice.
Compare and contrast valley glaciers with continental glaciers.
Valley- glaciers that form in valleys in high mountainous areas.
Continental- cover broad continent sized areas.
What are four features of glaciers?
- Arête
- Cirque
- Hanging Valley
- Horn
What are four landforms produced by glaciers?
1) moraines
2) outwash
3) drumlins
4) eskers
What are moraines?
Ridges consisting of till deposited by glaciers.
What is outwash?
Sediments deposited by meltwater.
What are drumlins?
Elongated landforms formed when glaciers move over older moraines.
What are eskers?
Long winding ridges of layered sediments that are deposited by streams flowing under a melting glacier.
What are four properties of minerals used for identification?
1) cleavage
2) hardness
3) lustre
4) streak
What are the two ways that minerals form?
From magma or from solution
How do minerals form from magma?
When magma cools as it is forced upwards into cooler layers of Earth’s interior, the compounds in magma no longer move freely and begin to interact chemically to form minerals.
How did minerals form from solution?
A given volume of water can only dissolve so much of a solid before the water becomes saturated. The saturated water can then not dissolve any more solids. If a solution becomes over saturated with another, mineral crystals begin to precipitate. Minerals can also form when elements dissolve in a supersaturated solution. when liquid evaporates from the solution, the elements remain behind and may begin to arrange into crystals.
Compare intrusive and extrusive igneous rocks.
Intrusive- coats-grained igneous rocks that cool slowly beneath Earth’s surface.
Extrusive- fine-grained igneous rocks that cool quickly on Earth’s surface.
What are the factors that affect magma formation?
- temperature
- pressure
- water content
- mineral content
Compare partial melting with fractional crystallization.
Partial melting- the process whereby some minerals left at low temperatures while other minerals remain solid. As each group of minerals melts, different elements are added to the magma, changing its composition
Fractional crystallization- when magma cools it crystallizes in the reverse order of partial melting. The process wherein different I reals form as different temperatures. As each group of minerals crystallizes, the changes occur because as each group crystallizes it removes elements from the remaining magma instead of adding new elements.
What are some common igneous rock examples?
Granite, gabbro, pumice, rhyolite
What are some common uses for igneous rocks?
Construction, memorials, kitchen tiles, countertops.
List and describe the steps in the formation of clastic sedimentary rocks.
Erosion- the removal and movement of surface materials from one location to another.
Deposition- sediments are deposited when transport stops. Particles then settle out, forming layers of sediment.
Burial- most sediments are deposited on Earth’s surface in depressions called sedimentary basins which contain layers of sediments that are more than 8 km thick. More layers are deposited and lithification takes place to to increasing pressure and temperature.
Cementation- occurs when mineral growth cements sediment grains together into solid rock.
Lithification- begins with compaction as the weight of overlying sediments forces the sediment grains closer together, causing the physical changes.
How do chemical sedimentary rocks form?
When the concentration of dissolved minerals in a body of water reaches saturation, crystal grains precipitate out of the solution and settle to the bottom. Layers of the chemical sedimentary rocks that form as a result are called evaporites.
Classify and name examples of clastic, chemical and organic sedimentary rock.
Rock Type:
Clastic: coarse, medium, or fine grained
Chemical: calcite, halite, and gypsum
Organic: calcium carbonate (shells), plant matter
Rock Name:
Clastic: conglomerate or breccia, sandstone, siltstone, shale
Chemical: limestone, rock salt, rock gypsum
Organic: limestone, coal
Method of formation:
Clastic: formed from the lithification of clastic sediments
Chemical: formed from the precipitation of dissolved minerals from water
Organic: formed from the accumulation and lithification of remains of living things.
Why are sedimentary rocks important for understanding the Earth’s past and natural resources?
Sedimentary rock contain valuable information about the Earth’s history. They contain fossils, preserve the remains of plants and animals, indicate the location and direction of ancient rivers, and the wave and wind direction over lakes. Many of the natural resources used by humans come from sedimentary rocks, such as oil, natural gas, coal, uranium, phosphate, iron, and limestones.
What are the ways that metamorphic rocks form?
Regional Metamorphism- when high temperatures and pressure affect large regions of Earth’s crust. Can be low, intermediate, or high grade which will reflect the intensity of temperature and pressure.
Contact Metamorphism- when molten rocks come in contact with solid rocks. High temperatures and moderate-to-low pressure from the mineral assemblages that are characteristic of contact metamorphism.
Hydrothermal Metamorphism- when very hot water reacts with rock and laters its chemistry. Hydrothermal metamorphism can dissolve some minerals, break down others, and deposit new ones.
What are some common metamorphic rocks?
Marble, schist, quartzite
What are the layers of the Earth?
Lithosphere -crust -upper mantle Mantle Asthenosphere Core -inner core -outer core
