Geology 1010 Test 2
How many categories of pyroclasts are there and what are they?
3, bombs, lapilli, ash
Why is this easy to differentiate and find?
Because they arrive at different times and travel at diff speeds, it's easy to differentiate this.
What are the 3 steps to building a fold?
Becomes ductile, compressed, bends
What is cementation?
Filling in all the pores between the rocks compacted, squeezes out water too cuz prsr from top pushes on bottom
Spot directly on a fault underground where motion from quake occurred?
Focus spots :) tip: if you want to know where the source of something is, or a quake you will focus on one specific spot underground
What is categorized under movements when referring to earthquakes?
Focus spots, epicenters, focus shocks, aftershocks
If a rocks has ductile responses to compressional forces and bends, its called___?
Folds
The piece of rock that does not incline is called the wat?
Foot wall. Just think about walking, you can only walk with your feet on a non inclined rock...because we cant defy gravity and the laws of physics! And one wall will always be above or "hanging" over you.
If a small earthquake happens before the main earthquake and you can barely feel it. What do we call this?
Foreshock ;) tip: fore= before shock. This happens before you are shocked by a massive quake!
What are biogenic sediments?
Formed by organisms (plant/animals) Ex: seashells, carbonate
What is detrital sediment and how is it formed?
Formed by physical weather, gravel sand texture that falls apart. -classifies based on grain size
What term refers to a fold being tilted or just evenly placed?
Genometry
If we find pressure ______ below earth's surface, how many bars/km depth does it =?
Gradient, 300 bars
What is feldspar rock?
Hard rocky but u can weather
.a popular island with a hotspot underneath it?
Hawaii, issues of plate tectonics, large bodies of magma under lithosphere. Plates move over area, pushes up chains of volcanoes
If a view of a rock and its layers is shown from the side and/or above the rock, it is known as what?
Horizontal geometry
Whats features of ash?
Inhalation, wtr mixes to form "concreteness". Piles up and collapses objects
What are some examples of physical weathering?
a. Plant roots brkn rock, b. Frost wedging
What are the steps of earthquakes?
a. Rocks in motion on either side of fault line. Low friction compared to stress b. Stress becomes equal to friction and fault line begins to disrupt some c. Stress is higher than friction and rocks slip along fault lines while releasing a ton of Potential E. fault line is very broken. d. REPEAT!
Whats features of Lapilli?
diamond size, raining gravel
Whats a tephra(cinder) volcano
stereotypical shape but small forming round edges around volcanoes. made from pyroclasts, barely magma
Shearing
stress that pushes masses of rock in opposite directions, in a sideways movement
Rock squeezed inward (from up and down motion)
stretching
What is the name of a fault moves horizontally past each other and is classified under right lateral or left lateral?
strike-slip fault
Why should we care about earthquakes?
It's destructive and we want to protect people from it.
Where was a case study done on an island volcano and what was significant about it?
Krakatoa in indonesia. Had explosion of 13,000x yield of hiroshima, 200 mil ton of TNT. 25 ft^3 ejecta. 30K ppl dead+ 2/3 of island destroyed.
What's dangerous pre-explosion
Lahar and pyroclasts
What is mass wasting and why do we care?
Landslides, hazardous cuz rocks benign pulled down could hurt ppl
what's a shield volcano
Large steepness is most common. flows easily across big surface, low silica content
Composite stereotypical volcanoes
tall, steep andesitic and rhyolitic magma. low temp, high silica, powerful explain, high Viscosity, don't take up a lot of land
Different fault types will form depending on what force being applied?
tectonic force
17. What is lithification
Layers stacking as time goes by and compacted, (compaction)
Which picture is displaced and which was deformed after sediment was deposited on top of it?
Left is deformed, right is split
What happens when sediment gets really wet n' saturated with buildings built on top?
Liquefaction (mudslides), and is very common
VERY VERY slow waves that only appear on the surface and cause a vertical/horizontal motion.
Long Surface waves
What are three things to pay attention to when studying landslides?
Materials present(mus, snow, ice), Movement (rolling, sliding, flow, fall) Speed (slow or fast)
Under deposition, what is accommodation space?
Measurement of how much sediment cur basin holds.
Viscosity
Measuring the resistance to flow
What are the 3 ways we can measure earthquakes?
Mercalli, ricketer, Moment magnitude scales
Exposed rock contacting hot fluids that flow through cracks and leaves behind sediments?
Metasomatism ;) tip: meta-som (meta=change, som= some. Leaves behind some change)
What measures the amount of split that occurred at the focus point and fixed spot?
Moment Magnitude scale
What are issues with the Richter scale?
Monitors have to be running before it starts and you can't use it to date old quakes,Can't date quakes from b4 the time of scale being invented.
What are the characteristics of a gentle non-explosion?
More gentle than explosive. Magma has a lot to do with this.
What's the causes of earthquakes?
Motion around fault lines and built up stress/ friction eventually releasing potential
What's the catch to the 4 causes of erosion?
Must have enough energy in the system to work.
Is lava the most dangerous part of eruptions?
No, pyroclasts and other things are
Is it true that we only use 1 machine to measure and detect earthquakes? If not, how may?
Nope, false. We use sets of 3.
3 Untrue myths about machines?
Old, needles swing, use only 1 machine
. What is formed by Metasomatism and happens at the same time, and is very valuable economically?
Ores
What factors play into which response you get from tectonic forces
Rock type, T/P, speed
What's saprolite formation?
Rocks easily weathered, decentigrates from a touch
When waves appear on one side of the earth but not the other side, what do we call this area?
S wave shadow zone ;) tip: shadows are not really seen or appear dark and a bit sneaky. Just like the other side of the earth without any waves lively vibrating through it ---> shadow zone
Waves shifting up and down, causes lots of damage and very slow through some solid materials that are brittle.
Secondary shear waves ;) tip: Mnemonic: Secondary shear waves can only shift though solid brittle stuff.
General name of a wave emitted from earthquake and has 3 dif types that happen in a series of hundreds?
Seismic waves
How do we measure or detect waves?
Seismometer/ seismograph
What are the ways in which we classify folds?
Shape, age of layers, geometry
What are the 3 tectonic forces
Shearing, tensional & stretching
Why do we care about sediments?
We live on the surface where they're used for a lot of different things and materials and need to avoid some of them like landslides.
How does sedimentary rock form?
Weathering parent particles from physical or chemical ways b. Erosion c. Deposition d. lithification
What's another example of supervolcanic eruptions?
Yellowstone Huckleberry ridge eruption covered 1/3 of the USA, global impact and less than 1/2 humans died globally.
Is it expensive to make changes to slopes? What's the perk tho?
Yes, but it will be more expensive if u wait, so do it now while its cheap
What's a huge perk of using the Moment Magnitude scale that WASN'T present with the Richter scale??
You can calculate even if you don't have a seismometer cuz you're using physical stuff here. AND it can be used for those old earthquakes b4 these machines were invented.
What are the types of deposition?
Basin, accommodation space, subsidence, layers
Why do we care about metamorphism?
Because it shows records of earth's history and produces a lot of exotic minerals.
How would a metamorphic rock appear on the surface?
Fault lines through a tectonic process and they come up through cracks
What's the equation for chemical weathering?
Feldspar + H2O + H2CO3 → kaolinite + dissolved ions
What is the US ranked for most active volcanoes?
US is actually ranked number 3
What is a misconception about volcanoes in the US?
"there's not as many in the US"
What is the estimated return of a prevention project for slope landslides?
$10-2K/ $1
How deep are foci?
2-20km
What are the ejecta V in order on the VEI?
0-8. <10,000 m^3 >10,000 m^3 >1,000,000 m^3 >10,000,000 m^3 > 0.1 km^3 >1.0km^3
Evidence of hot spots
1 island with a hot spot, rest are dormant. Hawaii is the youngest and biggest but others are older and smlr. The plates moved the islands and not hotspot sits under hawaii
If necessary to use more than one machine to measure quakes, what's the purpose of this?
1 machine=N, 1 machine =E, 1 machine =Up/ dwn
What does the logarithmic Richter scale range from using Arabic numbers?
1-10 (highest=10)
Mercalli scale index ranges from ___ to ___? But still doesn't tell us exact E releases.
1-12, 12 (being biggest)
What to do if a landslide is unsustainable?
1. Drain 2. Use building codes, decrease slope grades(height), retaining walls, rock bolts( only on hard rock)
What's the 4 causes of erosion?
1. Water 2. Wind power 3. Landslides 4. Glacial ice
What are the steps to P dropping and less dissolved gas?
1. gas exists liquid quick, moves to surface atmosphere depending on V 2. high viscosity, gas is stuck in magma and then explodes out big 3. low viscosity magma will allow gas to move faster= lil explosion
At what depth do metamorphic rocks form and at what crust level?
10-30km in the midlower crust
What is viscosity's temperature
1100oC
.What is Viscosity's silica content?
50%
What is the plume order on the VEI?
<100 m 100-1000 m 1-5 km 3-15 km 10-25 km >25 km
3 ways rocks respond to tectonic forces?
Acting Brittle or ductile
After earthquakes, we may feel a bit more potential E released from earth's plates. What do we call this?
Aftershock ;) tip: AFTER the main quake, we are shocked again by another mini quake → aftershock
What's the types of slope destabilization?
Angle repose, alot/tm water, lack/ excessive of vegetation,
A fold where rock layers bend upward resembling a persons frown?
Antiform ;) tip: anti means bad/against, frowny faces are against, or opposite of smiles and happiness
Basin falls under deposition. What is Basin?
Any place u can deposit sediment
Rock resists force until it breaks
Brittle
What are vesicle features?
Brittle jagged rock, pretty solid, lava preserved as vesicles cuz outside too solid for gas escape
What's Aa's features? and when does it appear?
Brittle, partially cool, jagged surface. appears days after eruption
How in the world do we measure earthquakes?
By using the Mercalli Index ;) tip: Cali (california) has a lot of earthquakes. Add "index" on the end to make it sound "official and scientific)---> Mercalli index
What are the 3 causes of metamorphism?
Change in Temp, Pressure increase, Metasomatism
What are the 2 features of lithification?
Compaction, cementation, rounding
What are the types of pressure?
Confining & Directed/differential
If an object is benign squeezed evenly from all directions, what kind of pressure do we call this?
Confining. ;) tip: (if ur in a confined space, there's no room ANYWHERE no matter the area or side. Ur tightly squeezed in)
A type of metasomatism process where parts of rock only close to something hot, changes (metamorphs), while the piece of rock not close to the hopt area, does not change at all
Contact metamorphism ;) Tip: (rocks has to come into CONTACT with sumthin' hot, then and ONLY then will it change and metamorph)
What are the 4 types of Metasomatism?
Contact, Regional, Fault, shock, metamorphism
What is a type of mass wasting that occurs slowly and takes years with a lot of response time?
Creep
What are the types of sediments?
Detritial, chemical, biogenic
What's the key to finding the focus point in earthquakes?
Different waves travel at different speeds. Map out their radiuses in general areas and see where they each intersect.
Is it easy or hard to predict earthquakes and why?
Difficult cuz every fault is different, variables play out different for different regions
If one fault has one block moving out and down over the other block, what do we call this?
Dip-slip hanging normal fault
If an object is confined from two directions only, and not the other two directions, what do we call this type of pressure?
Directional ;) Tip: (if ur being squeezed on ur head and you feet, but not your right and left sides of your body, the pressure is only DIRECTED on those two ends and nowhereelse.)
What are examples of chemical weathering?
Dissolve, oxidize, acid
What is low viscosity?
Doesn't resist flow ex: water
Rock is weak, bends and warps
Ductile
What's the cause of mass wasting? (triggers them)
Earthquake, cutting down trees, incorrect building of slopes?
What is kaolin rock?
Easy to break kaolin very easy to weather from touching
Spot on the surface directly about a focus spot?
Epicenter ;) tip: if you want to find the source on top of the ground as well, you need to find the epic center of the focus spot, ---> epicenter
How often do quakes happen?
Every 1-2 minutes
True or false, Moment magnitude does not use logarithmic?
False, it uses logarithmic and so does richter scale
All deep quakes in a region mainly do not occur in the same place, T/F?
False, they mainly occur in the specific location together within a region.
True/false, never treat age/ layers independently in folds?
False, u should treat them independently
True or false, if you are unsure of the fold name, You should randomly pick overturned synform, or overturned antiform?
False, you should just say you cant identify it or just call it an "overturned form" peridot.
Change along fault lines. Built up pressure and friction cause what kind of Metamorphic change?
Fault Metamorphism
What would we call a fold if its been tampered with and isn't completely facing down or up?
Overturned ;) tip: think about looking for artifacts and discovering something thathas very clearly and obviously been tampered with or overturnedbecause someone before you may have gotten there first.
.Waves that pass through any material in any state easily and cause expansion or contraction of materials. Very fast but little damage.
PWaves/ compressional waves ;) tip: when you have to Pee, your bladder feels Very compressed until you make it to the bathroom. This would not cause that much damage but you'd be very fast to get to a restroom!
What are the 3 nonexplosive features?
Pahoehoe Aa Vesicles
What is pressure measured by metamorphic changes?
Pascals and bars.
What are the two types of weathering called?
Physical and chemical
Having to view a rock from the side due to it being squeezed is known as?
Plunging geometry
Types of roundness?
Poor= jagged Moderate, kinda smooth but still not quite round well , rock is round shape
How do u classify the types of detrital materials\ Sort by roundness and uniform.
Poorly-well sorted & rounded\
most dangerous of eruptions
Pyroclastic flow
Opposite of contact metamorphism. P driven, large scale. Metamorphism happens with colliding and subduction zones here.
Regional metamorphism ;) tip: (regional is HUGE, think of a huge change on a large scale)
If a fault has one block move out and up, what do we call this type of dip-slip fault?
Reverse dip-slip fault
hat's two other ways we can get specific when measuring earthquakes?
Richter scale & Moment magnitude ;) tip: Rick and Morty will help measure earthquakes cause their "SO" scientific
What's the 3 different types of volcanoes?
Shield (most common) Tephra (cinder cone) Stratacones ("popular lookn'" composite)
What occurs when P increases, quick change from a comet or asteroid?
Shock Metamorphism ;) Tip: (if you're shocked about something, it is quick and sudden!)
How to damage control earthquakes?
Site selection, be selective where you build things and build on harder solid surfaces like rock and pavement rather than sandy sediment areas and then use building codes.
29. What do rockslides do?
Slide down the slope
What is a way to figure out which side of the fault has moved just from looking at it and the ground around it?
Stand on one side of the fault and face the other fault and whichever looks "off" is the one that has moved.
If theres two fault that simply move past each other, what do we call this?
Strike-slip fault
What is high viscosity?
Strongly resists flow. ex: peanut butter
Term for rocks deforming over time?
Structural Geology
Most earthquakes occur in what zones?
Subduction zones ;) tip: it would really SUCK to be in areas with earthquakes. (sub kinda..in a way... sounds like sub.
A fold where the youngest layers are in the center fold and fold around newer layers
Syncline, regards age of layers
A fold where layers bending downward is called a ___?
Synform ;) tip: smile, Synform both start with "S". "anti" is for the frowny facefold, and "Syn" with an "S" is for the Smiley face fold.
Rocks thats stretched (from up and down motion)
Tensional
How do you prevent landslides?
Use risk assessment maps, and always update them. But not really update volcanoes green= low incidence Orangish brown= highest expected incidence space
What is an example case study done? What prevention system could they have used and for how much money?
Thistle UT, did not fix slopes and hadda pay 200M instead of 1M. Coulda used drainage system for .5M
Where and what research was conducted where a supervolcanic eruption of 75Ka happened
Toba, how much magma built up and additional threat. Learned that volcanoes can continue to erupt years later.
What is erosion?
Transport of sediment particles
True or false, the oldest rock layers in forms is in the inner most core layer, whether that be at the top or bottom of the form because it may have been flipped in a synforms case.
True, tectonic plates can flip it upside down
What does 1 bar = ?
atmospheric pressure @ surface of earth at sea level
What are types of sedimentary rock and how are they formed?
chalk= shell particles limestone= calcite carbon coal= fossils
What is the frequency in order on the VEI?
daily weekly yearly >~ 10 yrs >~ 50 yrs >~ 100 yrs >~ 1000 yrs >~ 10,000 yrs
How fast is lava?
fast, 16 km/hr or 10 mi/hr
What is the name of a Joint response when rocks on the side of material breaks and occurs in sets
faults
What is the name for structures on earth that undergo deformation of rock layers?
geological structure
Whats pyroclasts?
igneous solid chunks of materials & rocks ejecta
A brittle response to tectonic forces when rocks cracked apart, occurring in sets.
joints
what is lahar
large liquidy mudslide flows with little friction, no response time available
Name one category of strike slip faults
left lateral
.If you were to stand in front of a fault, and the left side fault moves towards you while the right block moves away, what would we call this?
left-lateral strike-slip fault
what's pyroclastic flow
moves one big material, death @ 100mph, can't outrun, cooked and charred bodies
Do rocks actually swallow entire houses?
no
Name the 3 dip-slip faults
normal, reversal, thust
Types of sorting for grain size?
poor= bi, small and large particles moderate= medium/ small well= all sae size
What are the features of bombs?
range from hand size to a volkswagen
What's meant by supervolcanic eruptions?
refers to the eruption with global consequences. ex: tambora cause potato famine and frost in july in england cuz it blckd out sun long time
If you were to be walking along a dirt road, and realize suddenly, the road infront of you shift to the right, what would we call this?
right-lateral strike-slip fault
Change happens by magma heating seawater, seawater heats rocks, Creates change in rock. Sea water also turns rock green.
seafloor metamorphism
What's Pahoehoe features?
soft texture, crystalized film surface, fluid underneath
Faults occur in sets, T/F?
true