Exam 2

Question 1

What is the difference between a rock and a mineral?

Answer 1

Minerals are the letters of the alphabet and rocks are the words; minerals are what make up different rocks.

Question 2

What are the 6 requirements for a substance to be a mineral?

Answer 2

homogeneous 
naturally-occurring 
solid
generally inorganic substance with a 
definable chemical composition and an 
orderly internal arrangement of atoms

Question 3

What is a crystal lattice/crystal structure? What physical property does the crystal lattice control?

Answer 3

Crystal lattice- the orderly framework within which the atoms or ions of a mineral are fixed.
Crystal structure- the arrangement of atoms in a crystal.

The crystal lattice may control the shape of the crystal.

Question 4

How do minerals differ from glasses?

Answer 4

Glass has no organized molecular structure. Minerals have organized molecular structures.

Question 5

There are 5 types of bonds. Know them and know which are strongest and which are weakest.

Answer 5

Covalent - Strong
Ionic - Moderate
Metallic - Strong
Van der Waals - Weakest
Hydrogen - Weak

Question 6

What is a polymorph? Example? Why does graphite differ from diamonds? Why is carbon fiber (graphite) strong but the mineral graphite very weak?

Answer 6

Polymorph- Two minerals that have the same composition but different crystal form
Examples of a polymorph are graphite and diamonds. Graphite differs from diamonds because the carbon atoms in graphite are not arranged in tetrahedra like diamonds, but rather they occur in sheets.

Question 7

How do minerals grow? What is the difference between Euhedral and Anhedral? In what situation would each form?

Answer 7

There are 5 ways minerals grow:
Solidification of a melt
Precipitation from solution
Solid state diffusion (metamorphic rocks)
Biomineralization (shells)
Fumarolic mineralization (from a gas)

The difference between Euhedral and Anhedral is that Euhedral is a crystal with well formed crystal faces while Anhedral is a crystal with poorly-formed crystal faces.

Euhedral crystals form when there is sufficient space and time for the crystal to grow
Anhedral crystals form when space and time is limited.

Question 8

Types of physical properties: Color, Streak, Luster, Hardness, Specific Gravity, Crystal Habit, and Cleavage

Answer 8

Crystal habit: a mineral’s consistent shape. (Even if a crystal wants to grow a certain way, if a space is not available for it to grow that way it will grow just to fill in the space)

Cleavage: tendency of a mineral to break along the same plane (A Cleaver is used to cleave something off when cutting meat)

Fracture: Opposite of cleavage (Breaks in no specific orientation). BUT There is conchoidal fracture, which is useful for us to define minerals (Example is obsidian). This means that when you whack at the rock/cut it, it will shape into what you want it to become. Native americans used this with arrowheads, and people throughout history used this principle unknowingly to create cutting tools.

Question 9

Which is more useful, color or streak? Why do some minerals have no streak?

Answer 9

Streak because it is less variable than the color of a whole crystal; some minerals are too hard to have a streak

Question 10

Know the various types of luster. Do diamonds have metallic luster?

Answer 10

Luster is a property that describes how light is reflected on the surface of a mineral. Metallic and non-metallic. Diamonds do not have a metallic luster

Question 11

What is Moh’s hardness scale? What is the range? What are the hardnesses of talc, diamond, and quartz?

Answer 11

Moh’s hardness scale assigns basic minerals degrees of hardness on 1 through 10. Talc is 1, quartz is 7 and diamond is 10.

Question 12

Is Moh’s scale qualitative or quantitative? Why?

Answer 12

It’s qualitative. Each mineral on the scale is harder than the one before it, but not by a specific amount. Diamond is not 10 times harder than talc for example, even though diamond is 10 and talc is 1

Question 13

Is specific gravity different from Density?

Answer 13

It’s pretty much the same thing as density, it asks how dense a substance is

Question 14

What is cleavage? How do geologists describe cleavage? What is conchoidal fracture?

Answer 14

Cleavage: tendency of a mineral to break along the same plane.
# of individual directions for something to shine along a plane at \_\_\_ angles
Conchoidal Fracture is useful for us to define minerals (Example is obsidian). When you whack at the rock, it will shape into what you want it to become, creating very sharp edges. Native americans used this with arrowheads, and people throughout history used this unknowingly to create cutting tools.

Question 15

Special properties…magnetism, reaction to acid, striations, taste

Answer 15

Reacts to acid (calcite and dolomite: CaCO3 and Ca(Mg)(CO3)
Magnetic (Magnetite: Fe3O4)
Salty taste (Halite: CaCl)
Striations (Plagioclase Feldspar)

Question 16

Where do diamonds form? What conditions are required?

Answer 16

Diamonds are made of Carbon, and form from high pressure volcanic environment called Kimberlites.
Pressure compresses carbon into a diamond structure.

Question 17

Where do mineral deposits come from?

Answer 17

From rocks (finding chunks of a single mineral is kind of hard. We usually get chunks of rock with small minerals in them. 
Groundwater can move large mineral content around, and could deposit minerals in voids or Veins.
HOT Water is really really good for moving it.

Question 18

Be able to identify what mineral group a mineral belongs to if I supply the chemical formula

Answer 18

Silicates SiO24- Rock-forming mins
Oxides O2- Magnetite, Hematite
Sulfides S- Pyrite, Galena
Sulfates SO42- Gypsum
Halides Cl- or F- Fluorite, Halite
Carbonates CO32- Calcite, Dolomite
Native Elements Cu, Au, C Copper, Graphite

Question 19

Silicates: dominant rock group, form Si-O tetrahedrons, which link in many patterns, the ratio of Si to O controls many properties. Know them. How does the general structure of the silicate minerals crystal lattices change with temperature?

Answer 19

SiO ratio controls:
Mineral structure 
Cation present
Melting temperature
Viscosity 
Density 
Resistance to weathering 
Types of tetrahedra: 

Independent: minerals aren’t sharing any of their oxygens (linked by cations) e.g. olivine/garnet group. Highest temp. Minerals
Single-Chain Silicates: SiO ratio goes up, this chain is bonded with Fe and Mg. This gives us cleavage
Double-Chain silicates: Sharing up to 3 of their oxygens, and have two perfect cleavages. Gives us Flongate crystals. Compared to the previous two groups, once you get into double chains you get perfect cleavages, and crystals tend to be a bit elongated in one direction.
Sheet silicates: Instead of having two lines, all lines form together and make sheets of sio4 ions and some other stuff. You get minerals that form rocks that look like sheets. This only has ONE plane of cleavage (Crystal lattice structure is unbelievably flat). E.x all the Mica’s and some clay mineral group
Framework silicates: All 4 oxygens are shared, and some weird ass shapes are made. E.g feldspar group and silica (Quartz) group, which only contains Si and O.

Question 20

Lava & Magma: What is the difference?

Answer 20

Lava- melts at the surface

Magma- subsurface melt

Question 21

Extrusive/Volcanic vs Intrusive/Plutonic.

Answer 21

Extrusive/Volcanic- Igneous rocks that form due to the freezing of melts above the surface of the Earth

Intrusive/Plutonic- Form by freezing of melts below the surface of the Earth

Question 22

How do the following factors affect melting temperature? Pressure? Volatiles? Heat transfer?

Answer 22

As pressure increases, so does the temperature needed to melt something.

Question 23

Geothermal gradient: What is it? Does all rock follow the geotherm? Why or why not?

Answer 23

The rate of increasing temperature with respect to increasing depth in the Earth’s interior.
No. Because rocks hold their heat very well, and when moved, they may take considerable time to reach equilibrium with the local gradient.

Question 24

What do solidus and liquidus lines indicate? Be able to interpret a P-T diagram with solidus/liquidus lines.

Answer 24

liquidus is the lowest temperature at which an alloy is completely liquid; solidus is the highest temperature at which an alloy is completely solid.

Question 25

What do additional volatiles do to the solidus?

Answer 25

Addition of volatiles make melting easier, thus, the solidus temperature would move down

Question 26

Felsic, Intermediate, Mafic, and Ultramafic: what are these terms this based on? which are: most viscous? Most dense? Most SiO2? Most Fe/Mg? Highest temp?

Answer 26

Felsic has more Feldspar and is high in SiO2. Mafic has more Magnesium.

Question 27

Felsic, Intermediate, Mafic, and Ultramafic: what are these terms this based on? which are: most viscous? Most dense? Most SiO2? Most Fe/Mg? Highest temp?

Answer 27

Felsic has more Feldspar and is high in SiO2 (silica), which makes it very viscous. Mafic has more Magnesium.

Question 28

What is meant by dry magma or wet magma?

Answer 28

Wet magma (magma with water vapor) melts at a lower temperature than dry magma (magma with no water vapor)

Question 29

Why are there different compositions of magma?

Answer 29

Different minerals within a rocks melt at different temperatures and the amount of partial melting and the composition of the original rock determine the composition of the magma

Question 30

What is fractional crystallization? Know Bowen’s reaction series backwards and forwards (continuous and discontinuous) and what the implications are

Answer 30

Fractional crystallization is the removal and segregation from a melt of mineral precipitates; except in special cases, removal of the crystals changes the composition of the magma.

Question 31

How does partial melting affect a rock? What is a crystal mush?

Answer 31

It will cause the rock's composition to change. Crystal mush is crystallized magma

Question 32

What is stoping? A Xenolith?

Answer 32

Loping off chunks of wall rocks and assimilating the foreign rock (xenolith) into the melt, changing composition. Or they don’t melt and still seem a lighter color than surrounding rock when hardened.

Question 33

Why does magma rise?

Answer 33

Magma rises because hotter and less dense than the surrounding rock and therefore buoyantly rises and the weight of the overlying rock literally squeezes the magma out.

Question 34

What controls magma viscosity?

Answer 34

``` Temperature (high temp-low viscosity) Volatile content (more volatiles -less viscous) Silica content- silica tends to form silica-oxygen tetrahedrons that bond with each other to make long chains that ultimately resists flow (more silica-more viscous) ```

Question 35

Explosive vs Effusive…what controls this?

Answer 35

Explosive- high in silica (felsic-intermediate), low in temp, High in volatiles. Effusive- Low in silica (mafic), High Temp, low in volatiles.

Question 36

Know details of: Dike, Sill, Laccolith, Pluton, Batholith, Stock

Answer 36

Plutons: Non-tabular. Irregular blob shaped discorded intrusion (No real predictable shape, they just blob in and out). Can be hugee (bigger than states) or smol (10m) Batholith: big, pluton, non tabular Stock: small, pluton, non tabular Dike-igneous intrusions that cut across layering, i.e. discordant Sill-igneous intrusions that follow layering, i.e. concordant Laccolith- a dome-like sill that bends the layers above it into a dome shape

Question 37

What factors control cooling of magma?

Answer 37

Removal of volatiles, Surface area to volume ratio of intrusion (Tabular=fast, spherical=slow), temperature in area of cooling

Question 38

Know igneous textures, and igneous rock types

Answer 38

Glassy textures : mass of glass/tiny crystals surrounded by a glass matrix (Matrix being smaller stuff in a rock) Interlocking(Phaneritic) texture: Rock made of interlocking crystals that grew as the melt solidified fragmental : Rock made of fragments of other stuff (e.g. Crystals, Xenoliths(from volacano walls), glass) Tuff - white specks in rock are fragments, grey is ash

Question 39

Where does igneous activity occur? Why? What is the ring of fire? What causes the ring of fire?

Answer 39

volcanic arcs, isolated hot spots, continental rifts, mid-ocean ridges. Where a large number of earthquakes and volcanic eruptions occur. Caused by subduction of oceanic plates

Question 40

What is a LIP?

Answer 40

Large Igneous Province (Large area of Igneous Rocks). Might be a consequence of an igneous super plume Involve lots and lots of basalts

Question 41

How is sediment different than a sedimentary rock? What does it mean to be lithified?

Answer 41

Sediment is loose fragments of rocks or minerals, sedimentary rock is a rock that has been deposited and lithified into a single rock. Lithified is the process of Turning sediment into rock.

Question 42

Physical Weathering -> detritus (know names of various detritus sizes e.g. pebble, cobble, sand…etc as well as qualitative descriptions e.g. fine-grained, coarse-grained, etc.) Talus?

Answer 42

»Boulder > 256 mm (Coarse) »Cobble - between 64 and 256 mm (Coarse) »Pebble - between 2 and 64 mm (Coarse) »Sand - between 1/16 and 2 mm (Medium grained) »Silt - between 1/256 and 1/16 mm (Fine grained) »Mud < 1/256 mm (Fine grained) Talus: Apron or pile of debris at the margins of slopes

Question 43

Joints? Exfoliation joints? Wedging types?

Answer 43

Joints are cracks that just open when you stretch or contract rocks due to cooling off/drying out Exfoliation Joints are when deep rocks are exposed. They’re parallel to the topography, so they slide off at times. Frost wedging: Water freezing causes rock to crack and expand Root wedging: roots seep into cracks and expand them as they grow Salt wedging: evaporating lots of water as it flows through cracks, the salt crystals left behind can grow and push the rock apart

Question 44

Chemical Weathering -> know types

Answer 44

Best in wet/warm climates Dissolution: Dissolving of material. Affects carbonates and salts... when a chem breaks down minerals into new compounds. Results in rounding of edges (and can dissolve rock!) Hydrolysis: Water acts to Loosen chem bonds to break down materials Works fastest in acidic water Oxidation: When an element loses an electron, commonly when it bonds with oxygen Hydration: Absorption of water into some minerals (Mainly clays) causes them to expand

Question 45

Does surface area have an effect on weathering? What shapes are and weathered fastest? Slowest?

Answer 45

Ratio of surface area to volume of a material controls the rate of weathering. More surface area = more cracks Angular = not very weathered Rounded = very weathered

Question 46

How does weathering relate to Bowen’s reaction series? Exceptions: carbonates, evaporates, feldspars, oxides…Why?

Answer 46

Weathering rates basically follow bowen’s reaction series. Minerals want to be at their home. Mafic is at home when temp and pressure is high. Felsic is at home when temp and pressure is low. When taken out of its home, it’s much less stable and easier to erode. Exceptions occur when minerals are highly susceptible to chemical weathering

Question 47

What is differential weathering and what does it produce?

Answer 47

Under a given set of climate conditions: Different minerals and rock types weather at different rate Some form joints, some dissolve, some undergo hydrolysis, some do none of these A primary control on topography and landscapes: Strong rocks: Form higher peaks Weak rocks: Form valleys and low’s

Question 48

What basic factors control soil thickness?

Answer 48

Age The longer a surface has been exposed, the thicker the soil. Slope Steeper slope = less soil accumulating (e.g. bowl-shaped areas such as basins will accumulate thicc soil) Bedrock Type Thick soil will form over bedrock that’s easily weathered (e.g. Carbonates, evaporites, muds) Climate Thick soils will form in warm wet climates; deserts will form little or no soil

Question 49

What is diagenesis? What happens during diagenesis?

Answer 49

Big fancy word refers to all physical/chem changes that occur to form a sedimentary rock. Pressure, heating it slightly so that groundwater and other things can glue the rock together.

Question 50

Clastic Rocks…5 stages of formation? transport and grain size? How are clastic rocks classified (grain shape and size)? Know clastic rock types.

Answer 50

Erosion Transportation (move it from place to place) Deposition (Leave it alone, let it deposit somewhere. If it keeps moving it can’t lithify. Burial(Key part) Diagenesis and lithification (Big fancy word refers to all physical/chem changes that occur to form a sedimentary rock EXAMPLES: Sandstone, Mudstone

Question 51

Biochemical rocks – know types/names, how they form, and compositions

Answer 51

Rocks made of cemented shells of organisms Biochemical Limestone: Made of calcite, which was formed from remains of shells that secrete calcite or aragonite shells. Examples: Fossiliferous, Micrite, Chalk Biochemical Chert: made of microscopic crystals formed from the shells of plankton that sat on the seafloor and dissolved into a silica based ooze.

Question 52

Chemical rocks, know types/names and how they form.

Answer 52

Evaporites – products of the evaporation of water Main minerals: gypsum, halite Travertine (chemical limestone) – limestone that precipitated out of groundwater E.g. stalactites, stalagmites, also found at gysers & hot springs Dolomite – chemical alteration of limestone CaCO3 into dolomite CaMg(CO3)2. Happens when Mg bearing groundwater reacts with limestone.

Question 53

Organic rocks, know types/names and how they form.

Answer 53

Form from the accumulation and lithification of organic debris, such as leaves, roots, and other plant or animal material. coal, some dolomites, and some limestones

Question 54

Turbidity currents: what are they, where do they occur, and what kinds of deposits do they leave?

Answer 54

Underwater moving cloud of water and sediment (Underwater Landslide). They occur on underwater cliffs/slopes along coasts after storms when sediment gets turned up They leave turbidite deposits behind

Question 55

Turbidity currents: what are they, where do they occur, and what kinds of deposits do they leave?

Answer 55

Underwater moving cloud of water and sediment (Underwater Landslide). They occur on underwater cliffs/slopes along coasts after storms when sediment gets turned up They leave turbidite deposits behind

Question 56

Know bed surface markings types (e.g. mud cracks, fossils) and how and why they form

Answer 56

Mud cracks: Form when mud dries out and it contracts into hexagonal plates that curl along edges Scour marks: tracks left behind that are preserved. Scour marks made by currents flowing over sedimentary surfaces

Question 57

Know the various types of terrestrial environments discussed in class and the associated types of rocks

Answer 57

Terrestrial environments: Glaciers, mtn streams, alluvial fans, sand dunes, lakes Rivers

Question 58

How does transport distance affect clast shape/size?

Answer 58

The farther something is transported, the more rounded it becomes.

Question 59

Know the marine and carbonate environments and what kinds of rocks form in each.

Answer 59

Marine environments: Beach, shallow marine, deep marine, Carbonate environments: Tropical carbonate environments that hold a variety of sedimentary rocks

Question 60

Transgression and Regression – what do these terms mean? What are the implications for age of strata?

Answer 60

Changes in sea level are common throughout geologic time; Linked to Sedimentation Transgression : Sea level rise, Coastline moves inland (Well preserved) Regression: Sea Level falls, Coastline moves seaward (Not well preserved due to erosion) Means that a regional unit may not form laterally at the same time. You will get zigzag striped rock layers when it comes to regression

Question 61

Where do sedimentary rocks form?

Answer 61

Marine environmental/terrestrial environments

Question 62

Where do sedimentary rocks form?

Answer 62

Marine environmental/terrestrial environments

Question 63

What is metamorphism?

Answer 63

Alteration of the composition or structure of a rock by heat, pressure, or other natural agency.

Question 64

What does it not include? What causes metamorphism?

Answer 64

Does NOT include melting/weathering Causes: Heat: Increased heat allows bonds to break easier Pressure: Causes minerals with ‘open’ lattices to collapse, forming, more dense crystals. Differential Stress: When forces aren’t equal in all directions, minerals can deform/change shape Hydrothermal Fluids: Solutions that chemically react with minerals

Question 65

How are metamorphic rocks identified? What is a protolith?

Answer 65

Protolith is the original rock. Must identify: Textures (Grains interlocked/grew in place) Minerals(Certain only grow in the right heat/pressure, some of the craziest makeups) Foliation(Looks like layering, it is NOT layering. It’s the alignment of platy/alternating layers of light(Felsic) and dark(Mafic) minerals

Question 66

How are metamorphic textures formed?

Answer 66

Recrystallization: Changes in shape/size of grains, but the same mineral remains. Minerals just recrystallize and get bigger, they do not change. Phase Change: Mineral keeps the same composition but atoms arrange into a new form (polymorph) . E.g. Quartz (SiO2) can turn into Coesite (SiO2) Neocrystallization (Metamorphic Reaction): Result of chem. Process that decompose minerals and make new ones. Happens through diffusion of atoms through solid crystals Pressure Solution: Mineral grains dissolve where surfaces are in contact. Happens when rock is squeezed in one direction more than others, at low temps, and usually in presence of water. Usually a zigzag shape are common in carbonates. Plastic Deformation: At high temps, minerals can behave like soft plastic and become stretched/squished.

Question 67

What is differential stress and how is it different from pressure? Normal stress? Shear stress?

Answer 67

Pressure is stress that’s equal in every direction Differential stress is not equal in all directions and can change size/shape (Grain flattens) Normal Stress pushes or pulls perpendicular to a surface. Shear Stress moves one part of a material sideways relative to the other side

Question 68

Why does differential stress lead to the formation of a fabric/foliation? What is a fabric?

Answer 68

Grains will get flattened from equant>Elongagte>Tabular | Orientation of all the deformed crystals are its foliation

Question 69

What is a hydrothermal fluid? What about supercritical fluid? Where do hydrothermal fluids come from?

Answer 69

Solutions (not just water) that chemically react with minerals. Water becomes supercritical (Properties of liquid and gas, so it can permeate and fill spaces/diffuse like gas but also react like water) Causes metamorphic reactions to speed up and allows easy transport of ions/fluids Comes from groundwater, volatiles/water released from magma, and the release of water during metamorphic reactions

Question 70

What is metasomatism? What are Veins and how do they differ from joints?

Answer 70

Process where a rock’s chemical comp. Changes due to reactions with hydrothermal fluids. Commonly results in the formation of Veins, (Mineral filled cracks). Veins are filled with minerals, commonly wavy Joints are usually flat/not mineralized and are cracks in the rocks

Question 71

What is Foliation? What causes it? What can it tell us about stress?

Answer 71

Orientation of crystals that’s repeated over and over again that isn’t technically forming in layers. Caused by differential stress Tells us that stress occurred

Question 72

Know foliated metamorphic rock types and associated protoliths. Don’t worry about knowing specific protoliths of schist and gneiss…these could have lots of different protoliths.

Answer 72

Slate (Finest grained, caused by alignment of chlorite grains) Protoliths are Shale and Mudstone Phyllite (Fine grained, caused by alignment of mica and Flattened Clast Conglomerate (metaconglomerate): Schist Amphibolite: Protoliths (basalt, gabbro) can’t form felsic minerals so they form amphibolites. Typically foliated, but not always. Can be difficult to see foliation when all minerals are mafic. Gneiss

Question 73

Where did I leave off?

Answer 73

C 8 Question 18

Question 74

How is gneissic banding different from slaty cleavage?

Answer 74

Gneissic Banding- Starts off with this blob shaped thing, and then you start shearing it, which causes them to flatten and stretch. If you shear it more, you can start folding it over and over again. These folds are what cause the banding Slaty Cleavage -

Question 75

How does migmatite form and why is it both igneous and metamorphic?

Answer 75

Migmatite: combination of partially melted igneous and metamorphic rocks. It’s weird because it’s the exception to the melting rock rule. THe felsic stuff will melt first, and then forms an igneous rock. Technically felsic is igneous and mafic is metamorphic, but they just call it migmatite.

Question 76

Know nonfoliated metamorphic rock types and associated protoliths. Are they always nonfoliated?

Answer 76

Not all are foliated. Foliation is strongest when: Signif. Differential stress Rocks have elongated or platy minerals (e.g. amphiboles, micas) Involve metamorphism by temp, not high pressure or differential stress. Quartzite: quartz sandstone with larger interlocking quartz crystals. Looks glassier/more crystalline Marble: limestone and other carbonate rocks recrystallize into interlocking grains of calcite. Form compositional bands occasionally because marble flows at relatively low temps.

Question 77

Know names of the various metamorphic compositions

Answer 77

Idk

Question 78

Prograde and retrograde metamorphism…what are they and what is required for each to happen?

Answer 78

Prograde: Metamorphism that occurs While temp and pressure progressively increase. (Pro=for, I’m for this metamorphism) Most crystals with open crystal lattices end in OH2. So things like micas and a bunch of other things that end in OH2 will react and turn into new mineral phases with H2O as a product. No water during prograde = not much happening Retrograde: metamorphism that occurs when temp and pressure decreases (rock going back to surface conditions) If rock isn’t exposed to water during retrograde, it cannot form back to the minerals it started off as, causing it to look totally different.

Question 79

Prograde and retrograde metamorphism…what are they and what is required for each to happen?

Answer 79

Prograde: Metamorphism that occurs While temp and pressure progressively increase. (Pro=for, I’m for this metamorphism) Most crystals with open crystal lattices end in OH2. So things like micas and a bunch of other things that end in OH2 will react and turn into new mineral phases with H2O as a product. No water during prograde = not much happening Retrograde: metamorphism that occurs when temp and pressure decreases (rock going back to surface conditions) If rock isn’t exposed to water during retrograde, it cannot form back to the minerals it started off as, causing it to look totally different.

Question 80

What is a P-T path? What is an isograd?

Answer 80

Temp pressure increasing = prograde | Retrograde is opposite

Question 81

Contact metamorphism…what is it and what kinds of rocks does it involve?

Answer 81

where rock minerals and texture are changed, mainly by heat, due to contact with magma. Involves igneous rocks

Question 82

Burial metamorphism? Dynamic metamorphism? Regional metamorphism? Hydrothermal metamorphism?

Answer 82

Burial occurs when sedimentary rocks that had undergone diagenesis are buried even deeper. Diagenesis grades into burial metamorphism, a relatively mild type of metamorphism resulting from the heat and pressure exerted by overlying sediments and sedimentary rocks. When directed pressure or stress is the dominant agent of metamorphism, it is termed dynamic Most regionally metamorphosed rocks develop primarily in response to continent-continent collision and to collision between oceanic and continental plates Changes that occur in rocks near the surface where there is intense activity of hot water are categorized as hydrothermal metamorphism

Question 83

Subduction metamorphism? What facies is produced in subduction zones at depth?

Answer 83

Eclogite is produced.

Question 84

Where do we find metamorphic rocks? Where do they form? How do they get to the surface of the Earth?

Answer 84

They form inside of the earth, but can be surfaced through processes such as erosion

Question 85

Shock metamorphism? The rock cycle…how and why do rocks change into other types of rocks?

Answer 85

Also called impact metamorphism, occurs when high heat and pressures generated during an impact deform the underlying rock layers. Shock metamorphism can lead to planar deformation features, high-pressure polymorphs, and shatter cones, all of which provide evidence supporting a bolide impact.