Week 4 Flashcards
Rock cycle
Model that illustrates the origin of the 3 basic rock types and the interrelatedness of earth materials and processes
Igneous rock
Forms when molten rock solidifies. Can happen below or above the surface, or following a volcanic eruption. A result of CRYSTALIZATION
Sediment
(Clastic material) weathering breaks apart rocks that is transported and deposited to sediment
Sedimentary rock
Consists of particles derived from weathering of other rocks
Metamorphic rock
Crystallized rock formed through Solid state change: heat pressure and time. Rock formed by alteration of preexisting rock deep with in earth(still solid) by heat, pressure and or chemically active fluids
Crystallization
Magma cools and solidifies
Weathering
The disintegration and decomposition of rock at or near the surface of earth
Erosion
The incorporation and transportation of material by a mobile agent suck as water wind or ice
Deposition
When sediment is transported and deposited, biggest site is the ocean
Lithification
The process generally involving cementation and or compaction if converting sediments to solid rock
Metamorphism
rock is buried deep in the crust heat pressure and time change it to metamorphic, changes composition
Melting
Magma Forms when rocks melt deep beneath the surface
Molten material
Magma: molten rock that forms beneath earths surface
Characteristics used to determine the process that created the rock (2)
Mineral composition
Texture
Extrusive
Molten rock solidifies at the surface
Intrusive
Molten rock solidifies beneath the surface
Ways to transport material (4
Gravity
Water
Wind
Ice
Mineral rock
Rocks composed of minerals.
Cleavage
Tendency of a mineral to break along planes of weak bonding
Hardness
A minerals resistance to scratching and abrasion
Silicon oxygen tetrahedron
Elements abundant in the crust: A structure composed of 4 oxygen atoms surrounding a silicon atom that constitutes the basic building block of silicate materials
Silicate material
Any of the numerous minerals that have the silicon oxygen tetrahedron as their basic structure
Light (nonferromagnesian) minerals
Light in color, less gravity, contain aluminum potassium etc… NO IRON / MG
Dark (ferromagnesian) minerals
Contains IRON AND MG. Darker and have higher gravity
Characteristics of a mineral (5)
- Naturally occurring( geologic processes) ( not human/ lab made
- Generally inorganic
- Solid substance (ice, not water)
- Orderly crystalline structure:
- Definite chemical composition
How do rocks differ from minerals
Rocks are more loosely defined, a rock is any solid mass of mineral, rocks are composed of different minerals, some are 1 pure( limestone)
3 ways that minerals form
- Precipitation:
- crystalization of molten rock by cooking
- Mineral matter deposition by biological processes
4th way that minerals form (in class)
Solid state diffusion - slow movement of atoms through a solid, due to heat and pressure
What is a polymorph, give an example
(Many form)2 minerals with the same chemical composition with different internal structures and different formation environments
Example: graphite and diamond, when pure they are both just carbon. This is because they form at different places, depths, temperatures
What is the difference between a rock forming mineral and an economic mineral
Rock forming: Minerals that make up the rocks of the earths crust (abundant)
Economic: (less abundant) minerals used in manufacture of products.
Some rock forming minerals can be used in economic (calcite)
What is the most abundant mineral group, why?
Silicates, because the basic building block is silicon and oxygen, the most common elements in the earths crust.
Apart from color, what is the main distinction between light and dark silicates
Dark has iron and mg, making there be more gravity
Minerals are the ______ of rocks
Building blocks
Definition of a mineral
Any naturally occcuring inorganic solid that possesses an orderly crystalline structuring and a definite chemical composition that allows for some variation
Generally inorganic
You don’t need living things to make them. Inorganic crystalline solids such as table salt(halite) that are generally found in the ground are considered minerals. (Sugar is not, it is extracted)
Can also come from mammals secretion( calcite) in the form of shells or coral reefs, of they are buried and become part of the rock record they are minerals
What is an exception of a non liquid mineral
Mercury, is found in its liquid form in nature
Orderly crystalline structure
. Made up of atoms that are arranged orderly.(crystals)
Definite chemical composition that allows for some variation
We know what elements they are made of. Certain elements can substitute for others of similar size of similar size without changing the minerals internal structures
How do minerals form from precipitation
Water containing dissolved material matter(ions) a drop in temp and water lost from evaporation gets it closer to saturation. When saturation is reached the ions begin to bond forming crystalline solids(salts) that settle out (precipitation) from the solution
Crystallization of molten rock
Similar to water freezing. When magma is hot, the atoms are very mobile. As the molten material cools, the atoms slow and begin to chemically combine.
Mineral matter deposition from biological processes
Water dwelling organisms (coral mollusks clams) create limestone use calcium from water and secrete calcium carbonate and create reefs.
Clams secrete calcite and aragonite, the remains are buried and become part of limestone
Examples of dark silicates
Olivine
Pyroxenes
Amphiboles
Biotite mica
Examples of light silicates
Quartz Potassium feldspar Plagioclase feldspar Clay minerals Muscovite
Does glass have an orderly crystalline structure
No (not a mineral )
Is halite a mineral
Yes: orderly crystalline structure
Is ice a mineral
Yes, when water is solid
Melted- no
