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Earth Science
Earth Science Test Review March 15, 2012
89
Geology
Undergraduate 3
03/13/2012

Additional Geology Flashcards

 


 

Cards

Term
Characteristics of a mineral
Definition
  • Inorganic
  • Solid (or so book says)
  • naturally occuring
  • have a definite chemical composition
Term
We identify minerals by what?
Definition
  • cleavage
  • color
  • crystal form
  • hardness

 

Term
Intrusive rock
Definition
cools under the ground
Term
Extrusive rock
Definition
cools on the surface
Term
Plutonic rocks
Definition
  • Intrusive (cooled under ground)
  • This magma does not turn to lava as it does not exit.
  • Crystals are larger

 

Examples: Batholith, stock, sill, dike, laccolith

Term
Igneous rock
Definition
  • Most common is granite (also mica, quartz etc.)
  • Crystals are a pretty good size, cooled below the surface so intrusive
  • Have a high silicon content
  • There are two typs of Igneous rocks, Intrusive (Plutonic rocks such as Batholith, stock, sill, dike laccolith)  and extrusive (volcanic rocks which form when magma rises to the earth's surfice.) .
Term
The more viscous high silica magma a rock has, the more likely it is to cool where?
Definition
Below the surface to form plutonic igneous rocks.
Term
Sedimentary Rocks:
Definition
  1. Identified based on composition and thickness.
  2. Form horizontal layers or beds, youngest on top

 

Three types of sedimentary rock:

Clastic: Composed of rock and mineral fragments the most common type of sedimentary rocks. They are classified by grain size such as clay, silt, sand, and gravel.

Chemical sedimentary rocks: Form when minerals precipitate (crystallize) from a solution as a result of changing physical conditions (mainly due to evaporation.)
Biochemical: formed due to actions of living organisms that cause minerals to be extricated from solution or from the remains of dead organisms.

 

 

Term
Clastic Sedimentary Rocks:
Definition
  • Composed of rock and mineral fragments
  • Clastic Sedimentary Rocks are the most common type of sedimentary rock.
  • Examples: Mudstone, sandstone, conglomerate
Term
Chemical Sedimentary Rocks
Definition
  • form when minerals precipitate (crystalize) from a solution as a result of changing physical conditions.

Solutions = fresh water of lakes, ground water, or sea water

Changing conditions commonly = increased temperatures which causes evaporation.

Term
Biochemical sedimentary rocks
Definition

May form from the remains of dead organisms such as coquina -> limestone formed form broken shell fragments  or Coal ->carbon rich rock formed from compacted plant remains or chalk which is formed from billions of coccoliths round plates of calcite from microscopic clay sized coccolithophore organisms. (such as the white cliffs of dover.)

Term
Rock names reflect what?
Definition

size of grain.

Example:

Mudstone and Shale: made of clay silt-sized grains.

Sandstone: composed of sand sized particles

Conglomerate: made of gravel and larger fragments

Term
What kind of rock are the white cloffs of dover which look like chalk?
Definition
They are sedimentary
Term
Coal is....
Definition
a type of biochemical sedimentary rock
Term
Metamorphic Rock
Definition

Is created under ground in the crust. With heat and pressure any rock can become metamorphic. This happens in the crust of the ground.

Contact Metamorphic rock: changes due to increases in temperature where rocks come in contact with heat source (such as the magma chamber)(Examples: Limestone and marble) 

Regional Metamorphism: Increased heat and pressure associated with plate tectonic processes that form mountains.

Metamorphic rock examples: Schist, Marble, Geneiss, Slate.

Term
Contact Metamorphism
Definition

changes due to increases in temperature where rocks come in contact with heat source (e.g. magma chamber) Example: limestone around a magma chamber is baked by heat to form marble)

Term
Regional metamorphism
Definition

Increased heat and pressure associated with the plate tectonic processes that form mountains. If there is pressure that is pushing on the top and bottom then you have different crystals and get rocks with lines in them. So regional is all around, top, bottom, created by between heat and pressure.

Term
90 % of all quakes take place along what?
Definition
Tectonic plate boundaries
Term
Pyroclastic rock
Definition
loose rocks thrown out of a volcano.
Term
Earthquakes at volcanoes are caused by:
Definition
molten rock rising and breaking rock so it can get out.
Term
Calderas are
Definition
Depressions much larger than the original crater
Term
Relative time
Definition

is "which came first, or second. It does not come with specific numbers. The oldest layers are at the bottom. The layers of rock can get twisted or tilted. There is no absolute time, but there is relative time when dating rocks.

Term
Three types of volcanoes
Definition
  • Shield volcano: big and flat
  • Cone volcanoe: can be peaked but wider than stratovolcano
  • Strata Volcano: super peaked
Term
How do they date they sedimetary rock?
Definition

by the fossils. The fossils are in the same order in the same type of rock regardless of what the rock cut looks like.

Term
Proton
Definition
  • a particle of the nucleus of an atom
  • carries a positive charge
  • Protons plus neutrons = mass number
  • Number of protons = the atomic number
Term
Neutron
Definition
  • is an particle of the nucleus
  • It has a negative charge
  • Protons plus neutrons equals the mass number.
Term
Atoms must have equal numbers of:
Definition
protons and electrons
Term
If an atom does not have equal numbers of protons and electons then it is an
Definition
ion
Term
Isotopes
Definition

are the same as the element they are named after but they have a different number of neutrons than protons. The parent isotopes are not stable but the daughters are. (They are broken down by radioactivity.)

Term
Half life
Definition

is the period of time it takes for the amount of a substance undergoing decay to decrease by half.

Term
Radioactive isotopes in clastic sedimentary rocks always predict an age that is
Definition

older than sedimentary rock. The isotope clock didn't get reset when it got stuck together in the seminary rock.

Term
Uniformitarianism
Definition

states that the features on earth's surface were formed by the same slow processes that we see operating today. The problem is that not everything may have happened a the same rate. The present is a key to the past, true but the timing could have been much slower or faster than we think. (Such as EGW says there was a big wind after the flood which dried up the waters quickly.)

Term
Physical weathering
Definition
Disintegration of rocks and minerals into smaller pieces because of weather.
Term
Unloading
Definition
as the layers of rock peel with decreasing pressure causes underlying rock to expand upwards.
Term
Wedging
Definition

water enters cracks in the surface of rocks and roads. Temperature drops causes water to freeze and expand in the cracks forcing the cracks to widen.

Term
When you see pressure release cracks  in rocks you will see
Definition
Layers
Term
Round holes in cliffs weathering is usually the result of:
Definition
salt crystal growth on the surface of the rock.
Term
Chemical weathering
Definition

the decomposition of rock due to chemical break down of minerals is called chemical weathering.

Dissolution: minerals in a rock are dissolve by water

Example:  = acid rain removes detail of a statue

Term
The most common type of caves are
Definition
limestone caves (especially in TN)
Term
True or false: A ph of 2 is more acidic than a pH of 6
Definition
True
Term
Macroscopic biological weathering example:
Definition

Chitons (a type of mullusk) wears away at limestone.

Sea Urchins excavate holes in bedrock

 

Term
True of False  a rockfall consists of one, or a very small number of large rocks
Definition
True
Term
Landslides are more likely to occure in the Appalachian or in the Rocky Mountains?
Definition
Apalachians due to so much more rain.
Term
Name things that are found in debris flows
Definition
Soil, rocks, trees, shrubs
Term
Piles of loose sand forms slopes that are approximately ___ degrees on the sides
Definition
35 degrees
Term
What are the four types of landslides?
Definition
Rockfall, Rockslide, Slump, Creep
Term
Mass Wasting is the movement of _____ down the slope
Definition
material
Term
Name a location in Collegedale area that is prone to landslides
Definition
  • Ridge cut
  • I-40
  • Highway 64
  • Jenkin's Road
Term
___ is the primary force that causes materials to move down a slope
Definition
Gravity
Term
The law of original __________ is the concept of how rocks are initially laid down.
Definition
Horizontality
Term
Three types of weathering
Definition

Physical

Chemical

Biological

Term
True or false Limestone rocks are often eroded by Chemical weathering
Definition
True
Term
Index Fossils in Sedimentary rocks can tell us the exact age of the rocks they are found in..true or false?
Definition
False
Term
Sedimentary Rocks can or can not be age dated using radioactive isotopes?
Definition
Can not
Term
If I have 1,000 atoms of something that have a half life of 704 million years, after 704 million years how many parent verses daughter atoms are there?
Definition
500 each
Term
The law of ________ tells geologists that rock layers beneath other rock layers are older
Definition
superposition
Term
Two land features that formed by chemical erosion...
Definition
Sink holes and Caves
Term
A low viscosity material flows easier or harder than a high viscosity material?
Definition
low viscosity flows easier than high viscocity. (Low viscosity like oil and high viscocity like peanut butter.)
Term
The viscocity of a material like Peanut Butter (decreases or increases) if the temperature of the product is increased?
Definition
Decreases
Term
Mt.Saint Helens belongs in what catagory of volcanoes?
Definition
Stratovolcano
Term
Most active volcanoes on continents are located at  ______ plate boundaries
Definition
Convergent
Term
True or false...Mt. St. Helens is the most active volcano in the continental USA?
Definition
True
Term

True or false...a shield volcanic mountain is made by magma that blasts out of the vent in large bombs, debris, ash thrown high in the air.

 

Definition
False
Term
The crust under mountains is thicker or thinner than the crust under other parts of continental crust?
Definition
Thicker
Term
The Hawaiian Islands are located at a plate boundary (true or false)
Definition
False
Term
The height of mountains are influence by a combination of rock density and isostasy (true or false)
Definition
True
Term
Isostasy
Definition
a balance between the topography of Earth's surface and  thickness and density of the underlying rocks. (see pages 166,167 in the book)
Term
Volcanic eruptions produce a variety of material. Name some materials produced during an eruption.
Definition

Gases, Tephra (boulders and ash) lateral blast, Laval, Pyroclastic flows (a fast moving current of super heated gas and and rock usually hugging the ground traveling at speeds up to 450 mph) , Lahar (a type of mud flow or debris flow composed of a slurry of pyroclastic material, rock debris and water typically along a river valley.)

Term
If the crust were more dense, the mountains would be higher or lower?
Definition
higher
Term
What is the name of the scale used to test hardness of different minerals?
Definition
Mohs
Term
What does the Moh's hardness scale do for us?
Definition
It helps us identify minerals by their scratch resistence
Term
Two types of Igneous rocks
Definition
  • Intrusive (cools under the surface) and
  • Extrusive (cools on the surface)
Term
A stable element has the same number of what?
Definition
Electrons, neutrons and protons
Term
Clastic Sedimentary rocks are composed of bits and pieces of other rocks (true or false)
Definition
True
Term
Silica is one of the most common compounds on earth. (True or false)
Definition
True (I believe that the more silica a rock has, the lighter color it is, but I could be wrong.)
Term
This is a strange question on a quiz but it says to give an example of contact and regional metamorphism
Definition
  • Contact: cooking a piece of toast
  • Regional: cooking an entire loaf of bread.
Term
Geologic Time is called
Definition
Relative time
Term
What is our clock for planet earth?
Definition

Radioactive decay

 

Protons (positively charged)repel each other. This repulsion is balanced by neutrons acting as a buffer but in some isotopes the repulsion is too great = unstable isotopes. An unstable nucleus may spontaneously change to a more stable form through radioactive decay. So radioactive decay releases energy (heat). The unstable original isotope is the parent and the stable new isotope is the daughter.

Term
The concept of Uniformitarianism suggests
Definition
that ancient mud cracks formed under the same conditions that form modern mud cracks...or that the present is the key to the past.
Term
How is surface area affected by weathering?
Definition
The more surface area there is the faster it weathers.
Term
What are the three types of weathering? (Listed previous but separately)
Definition
Physical, chemical, biological.
Term
What erodes soil?
Definition
Wind and Water
Term

Dirt is composed of four things

 

Definition
  • Geosphere:Regolith (rock and mineral fragments)
  • Hydrosphere: Water
  • Atmosphere: Air
  • Biosphere: Organic Material
Term
On the average soil consists of what percentage of what?
Definition
  • 45 % mineral fragments
  • 25% water
  • 25% air
  • 5% organic material
Term
Physical Weathering: Unloading
Definition
  • Erosion strips away overlaying material
  • Decrease in overlying pressure (load) causes underlying rock to expand upward
  • Leads to pressure release cracks in the exposed rock.
Term
Physical weathering: Wedging
Definition
  • Water enters cracks in surface materials (rocks, roads)
  • Temperature drop causes water to freeze, expand, and force the cracks to expand.
  • Process repeats when the ice melts, water finds new cracks, freezes again and expands the cracks. Example: Potholes.
Term
Chemical Weathering
Definition
  • Dissolution: Minerals in rock are dissolved by water. Example: Acid rain removes details of a statue.
  • Hydrolysis: Hydrogen ions in water replace other ions in silicate minerals. Example: Feldspar reacts with water and Hydrogen ions to form clay with is usd in manufacturing glossy magazine paper.
  • Oxidation: Oxygen reacts with iron and other metals to form new mineral compounds Example: the rust on your car.
Term
Biological weathering occures in what two ways?
Definition
  • Macroscopic: by organisms we can see such as plant roots, animal burrows, termites
  • Microscopic: By organisms we can't see with the naked eye. Primarily caused by decomposition of material that converts solid material to gases with or without water. Works mainly on organic material such as dead plant or animal matter.
Term
Substances ejected by volcanoes
Definition
  • Tephra: particles blasted into the air by eruption such as volcanic bombs and ash found near and from from eruption source.
  • Low viscosity lava can flow 50Km or more.(high viscosity stays closer by)
  • Pyroclastic flow: dense cloud formed from combination of tephra and volcanic gases
  • Lahar: mudflows formed when volcanic debris mixes with streams and melting ice and often confined to stream channels.
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