test 2 Flashcards
How many element account for 98% of earth’s mass?
8 element (Iron, oxygen, and silicon)
What makes up 75% of the earth’s crust?
Oxygen and silicon
Center of the earth is more ____ , as it expands it is less ___.
Dense (Iron center, lighter element migrate to the crust)
Earth’s early molten, (or nearly molten) state under influence of _____, heavy element sank to the ____.
gravity, center
Minerals are
Naturally occurring, Crystalline solid, orderly and repeating arrangement of atoms, ions, or molecules, definite chemical composition, and inorganic (non living)
Minerals are classified by
Chemical composition (what it is made of ) Crystal structure (how it is arranged)
______ is the formation and growth of a solid from a liquid or gas.
Crystallization
Minerals are identifiable by there ____ form
Crystal
Some minerals can have same composition but different ______ structure.
Crystal (example Carbon can made graphite or diamonds)
Graphite and diamonds have different arrangement of the same atoms is called _____.
Polymorphs
Crystal form -Crystal shapes in the outward expression of a mineral’s internal arrangement of atoms. Which condition effect the grow of the crystal?
Temperature, pressure, and space for growth
Hardness is the _____ of a mineral to ______
Hardness, scratching (Hardness depends on the chemical bonds and strength is determined by the ionic charge, atom size and packing)
______ is the property of a mineral to break along planes of weakness (determines by crystal structure and bond strength)
Cleavage (breaks straight)
_____ occurs in mineral where bond strength is generally the same in all direction.
Fracture (breaks along curvatures)
Mineral that ______ do not exhibit ______
fracture, cleavage
_____ is obvious feature but not a reliable for identification. Using a the _____ is the true color of the mineral.
Color, streak
______ is the ratio of a mineral’s mass to its volume. How heavy a mineral feels.
Density
Physical properties of a mineral are predominantly related to
A the external condition of temperature, pressure, and amount of space available for growth
B The chemical composition and internal arrangement of the atoms that make up the mineral.
C.crystal form, hardness, cleavage and fracture and density
B The chemical composition and internal arrangement of the atoms that make up the mineral.
The color of a mineral is related to
A it chemical composition
B its luster
C its internal arrangement of atoms
A it chemical composition
There are two classification of minerals
silicate minerals (silicate) and non silicate minerals (oxygen)
______ mineral make up more than 90% of the earth’s crust.
Silicate
Silicate are divided into two groups :
Ferromagnesian silicates and non Ferromagnesian silicates
______ silicates contain iron or magnesium. Tend to have high density and are dark colored
Ferromagnesian
______ silicates have no iron or magnesium and are low density and light in color.
non Ferromagnesian
________are more important for us (gold, diamond, copper) we have less of these resources.
non silicate
The silicates are the most common and abundant mineral groups, because silicon and oxygen are
A the hardest element to find
B the two most abundant elements in the Earth’s crust
C Found in the mineral quartz
B the two most abundant elements in the Earth’s crust
Non silicate mineral make up about ____ Earth’s crust.
8%
Minerals form by the process of ______
Crystallization
Mineral crystallize from two primary sources.
Magma (molten rock) and water solution
Mineral crystallize systematically based on their _____ point
Melting
The first mineral to crystallize from magma are those with the ____ melting point and the _____ amount of silica.
highest, lowest
The last mineral to crystallize from a magma are those with _____ melting points and ___ amounts of silica
lower, higher
Water solutions can precipitate chemical sediment such as carbonates and evaporate
Low solubility mineral precipitate ___.
1st
High solubility mineral precipitate ____
last
In the crystallization of chemical sediments from water solution, low solubility minerals precipitate first because
A they dissolve more easily
B they are infinitely soluble
C they are not easily dissolved
C they are not easily dissolved
_______ formed from cooling and crystallization of magma or lava
Igneous
_____ formed from preexisting rocks subjected to weather and erosion
Sedimentary
_____ formed from preexisting rock transformed by heat, pressure, or chemical fluids (changes without melting)
Metamorphic
____ is molten rock from inside the earth. ____ is molten erupted at the earths surface.
Magma, Lava
Even though the temperature at depth is hotter than rock’s melting point, the rock at depth are solid, because
A. they are under enormous pressure from the rock above
B increased pressure their melting
C. temperature would have to be even higher to counteract the increase in pressure
D all the above
D
Three types of magma
Basaltic (ocean floor dark) Andesitic (gray) Granitic (light color, land mass)
Intrusive or plutonic rocks form ____ of the earth
inside
Extrusive or volcanic rocks form ____ of the earth
surface
Three types of volcanoes are
Shield, cinder cone, and composite
Shield and cinder cone have ____ amount silica making lava running. Composite have ___ amounts of silica thick.
Low, high
_____is the most common plutonic rock
Granite
Weathering the physical breakdown and chemical alteration of rock at Earths surface.
Two types of weathering are
mechanical and chemical
Sedimentary rocks are product of 4 process
weathering, erosion, Deposition, Sedimentation
Mechanical weathering can be ____ ____ ( freezing and thawing of water) ______ ____ (expansion and contraction due to heating and cooling ), and ____ ____ (disintegration from plants and animals)
Frost wedging, thermal expansion, biological activity
_____ the physical removal of material by mobile agents such as water, wind , ice or gravity.
It involves movement.
Erosion
Lithification occurs in two steps __ ___
Compaction and cementation
_____ weight of overlying material presses down upon deeper layers.
compaction
________ compaction releases “pore water” rich in dissolved minerals. Acts as a glue to cement sediment particles together
cementation
Sedimentary rocks are based on two types
Clastic rocks and chemical rocks
____ transport sediment particles bit and pieces of weathered rocks (shale, sandstone, conglomerate)
Clastic rock
______ sediment that were once in solution (travertine, halite, limestone)
Chemical rock
_____ abundant chemical rock
Limestone
_____ trigger the deposition of chemical precipitates.
Evaporites
_____ is different from other rock because it is composed of organic material.
Coal
The most characteristic feature sedimentary rocks is
A they contain fossils
B the lithification and cementation of sediments
C the layered sequence of strata
C the layered sequence of strata
Metamorphic rocks are produced form
igneous, sedimentary, and other metamorphic rocks
Metamorphic rock occur via ______ and _____ deformation
recrystallization mechanical
Contact metamorphism - a body of rock intruded by magma/ associated with high temperatures and high water content
(lots of chemical activity, not much or no mechanical deformation)
Large areas alteration by both heat and pressure
Regional metamorphism
_____ layered in sheets (slate, schist, geneiss)
Foliated
_____ not layered (marble and quartzite)
Nonfoliated
Marble is an example of
A crystalline, metamorphosed limestone
B foliated metamorphic rock
C nonfoliated mica
A crystalline, metamorphosed limestone
What was the rate of cooling and the environment of formation for an extrusive igneous rock.
Fast because it was erupted from a volcano
What creates the small holes found in a vesicular texture
Weathering
_____ is the process where sediments are converted into a sedimentary rock.
Lithification
_____ describes the range in particle sized in a detrital sedimentary rock
Sorting
The metamorphic equivalent of limestone is
marble
In a sedimentary rock, small rounded particles indicate
a long distance and long time travel time
_____ is composed of alternating bands of light and dark silicate minerals
Gneiss
The primary agent of contact metamorphism is
heat
_______ is the assumption that Earth’s geog logy is the result of slow processes over long periods of time
Uniformitarianism
______ relative age, the ordering of rocks in sequence by comparative ages
Relative dating
______ absolute age, actual age of rock determined in a laboratory.
Radiometric dating
____ new layers of sediment are horizontally laid down over older layer
Original horizontality
____ in undeformed sequences of rock, top layers are younger than bottom layers
superposition
_____ a fault or intrusion that cuts into a rock is younger than the rock it cuts through
Cross cutting
Any inclusion is older than the rock containing it
inclusion piece of rock
_____ allows us to date separates rock outcrops from similar characteristics
lateral continuity
______ Fossil organisms follow one another in a definite, irreversible time sequence.
Faunal succession
The embedded rocks (inclusions) in the sedimentary layers are
A metamorphic
B older than the sedimentary layers
C younger than the sedimentary layers
B older than the sedimentary layers
Uncomformites are ___ in the rock record
Gaps
__ ___ the time it takes for half of the parents isotopes to decay to their daughter product
Half life
Radiometric dating can give the actual age of a rock. An exception to the actual age” can be found in
Sedimentary and some metamorphic rocks
______ time ranges 4.5 billion years ago to 543 million years ago
Precambrian
Blue/ green algae or cyanobacteria and volcanic
Precambrian
Three type of atmosphere
1ST hydrogen and helium
2nd from volcanic out gassing rich in CO2 and H2O h2o formed the oceans
3rd removal of co2 to rocks nitrogen increased oxygen increased development of o3
The development of free oxygen was crucial to the emergence of life on earth because it led to the formation of
Ozone which screen earth from harmful incoming UV radiation
____ era 300 million year ago to six period.
Fossil with hard body organisms showed up, rise is sea levels and marine life.
Palezoic
_____ 543 to 490 Ma Hard bodied organism Forming outer skeleton
Cambrian period
______ 490 to 443 Ma Emergence of vertebrates (jaw less fish) Landmasses on journey to become southern continent of Gondwanaland
Ordovician period
______ 443 to 417 ma terrestrial life- plants, scorpions, and millipedes
Silurian period
_____ known as the “age of the fish” 417 to 354 north America join the northern hemisphere “Pangaea”
Devonian period
Deposition of sediment with each layer younger than they layer below is referred to as the principle of
A. nonconformity
B. superposition
C. original horizontality
B. superposition
A surface of erosion between rocks that represent a gap in the Earths history is
A. a faunal conformity
B. an unconformity
C. called a dike
B. an unconformity
If the half-life of some radioactive element is 1 billion years, and a mass of rock originally contained 100g of that element, how many grams of the radioactive element would be left after two billion years had passed? A 6.25 B.12.5 C.25 D. 50
C.25
The _____ is the idea or concept that ancient life forms succeeded each other in a definite, evolutionary pattern and that the contained assemblage of fossils can determine geologic ages of strata?
A law of fossil regression
B principle of faunal succession
C principle of cross correlation
B principle of faunal succession
During the Precambrian. the development of the ozone layer helped
A promote the emergence stromatlites
B to shield the Earths surface from harmful uv radiation
C. Promote the development of anaerobic organisms
B to shield the Earths surface from harmful uv radiation
The most important event that marks the beginning of the Paleozoic Era was the
A. emergence of the trilobite.
B. ability of organisms to form an outer skeleton
C. ability of the organisms to develop lungs
B. ability of organisms to form an outer skeleton
The most common Precambrian fossils are ____, layered mounds of calcium carbonate.
A. trilobites
B. porkaryotes
C stromatolites
C stromatolites
Which one of the following represent the greatest expanse of geological time?
A. Paleozoic
B. Mesozoic
C. Precambrian
C. Precambrian
The ______ period 354 to 290 Ma
Insects moving to land, Amniote egg key to reptiles
Carboniferous
The ___ Period 290 to 248 Ma
Extinction of 95% marine species. 70% land species
Permian
Causes of extinction in Permian period
Redistribution of water and land
Changes in land mass elevation
Climate change
Lowering of sea levels
_____ era 180 million years from 248 million about 65 million years ago
Three Periods Triassic, Jurassic, Cretaceous
Often call the “age of the reptiles”
Mesozoic
____ breaking up of Pangaea, Flowering plants, 1st true reptiles, insects
Mesozoic
How did Mesozoic era end
Large asteroid or comet struck earth
extensive volcanism occurred came out of the fissure cracks in the earth (gas in the air)
_____ 65 million years ago to present know mammals
Two Periods Tertiary, Quaternary
Cenozoic era
\_\_\_\_\_ era Climates cooled Glaciation in temperature 1/3 of land covered by ice Marine mammals and large land Humans Multiple ice ages
Cenozoic
Glaciation during the Cenozoic resulted in
A. lowering of sea level world wide
B. carving of the Swiss Alps
C land bridge connections between various continents
D all of the above
D all of the above
