GEOL 1301 Chapters 1, 3-8 questions
what role does water and volatiles play in the formation of magma?
cause rock to melt at lower temperatures
what minerals are susceptible to oxidation?
olivine, pyroxene, hornblende, biotite
why do volcanoes like mount st. helens erupt explosively, whereas others like kilauea are relatively quiescent?
magmas associated with mount st. helens are more viscous than kilauea because they have more silica
how did Aristotle believe rocks were created?
under the influence of stars
the principal of _________________ states that physical, chemical, and biological processes at work shaping the earth today have also operated in the geologic past
uniformitarianism
match the steps of scientific method with the appropriate order from first to last a. observations and experiments are developed to test the hypothesis b. data is collected that relates to the question c. hypotheses are rejected, modified, or accepted d. results are shared with scientific community e. a question is proposed about the natural world f. questions are posed and a hypothesis developed
1 - e, 2 - b, 3 - f, 4 - a, 5 - c, 6 - d
what is the ratio of oxygen to silicon found in single tetrahedrons?
4 to 1
how old is the earth?
4.6 billion years old
what differentiates cleavage from fracture?
Cleavage - mineral breaks along planes of weak bonding Fracture - minerals have chemical bonds equally strong in all directions
"the present is the key to the past" who said this and about what?
James Hutton, uniformitarianism
how does magma differ from lava?
Magma - molten rock beneath earths surface lava - molten rock at earths surface
match each of these volcanic regions with one of the three zones of volcanism (1. convergent plate boundaries, 2. divergent plate boundaries, or 3. intraplate volcanism) a. Crater Lake b. Hawaii's Kilauea c. Mount St. Helens d. East African Rift e. Yellowstone f. Mount Pelée g. Deccan Plateau h. Mount Fujiyama
a - 1, b - 3, c - 1, d - 2, e - 3, f - 1, g - 3, h - 1
what is the process of the formation of coal?
accumulation of plant remains, formation of peat and lignite, formation of bituminous coal, formation of anthracite coal
what is the difference between an atom and an ion?
an atom is neutral and an ion has a charge
what are the six major igneous rock textures?
aphanitic, phaneritic, porphyritic, vesicular, glassy, pyroclastic
what is the difference between bombs and blocks of pyroclastic material?
bombs - ejected as incandescent lava blocks - made of hardened lava
what do muscovite and biotite have in common?
both apart of mica family
what is a similarity between granite and rhyolite?
both composed of light colored silicates
what are three terms that describe tenacity?
brittle, malleable, sectile
How can slate and phyllite be differentiated?
by phyllite's glossy sheen and wavy surface
what are three common cements?
calcite, silica, iron oxide
a large depression at the summit of a volcano is called a _____________.
caldera
what is the difference between a crater and a caldera?
caldera is much larger than a crater
what is the difference between mechanical and chemical weathering?
chemical weathering changes mineral composition and mechanical weathering does not
what are two textures used to classify sedimentary rocks?
clastic, nonclastic
what is the most influential factor in soil formation?
climate
what is the difference between conglomerate and breccia?
conglomerate has rounded particles, breccia has angular particles
what are three broad categories of sedimentary environment?
continental, marine, transitional
which type of plate boundary is associated with regional metamorphism?
convergent plate boundaries
what is the main difference between light and dark silicates?
dark silicates have greater specific gravity than light silicates
what are the three sedimentary rock categories?
detrial, chemical, organic
what is the difference between confining pressure and differential stress?
differential stress applies stress in one direction, confining pressure applies pressure in all directions
what are the three types of chemical weathering?
dissolution, oxidation, hydrolysis
which of the three types of plate boundaries has the greatest quantity of magma generated?
divergent - 73%
what are three types of chemical sedimentary rocks?
dolostone, chemical, chert
what role do chemically active fluids play in metamorphism?
enhance it by dissolving and transporting ions from one site in the crystal structure to another; facilitating process of recrystallization
why do extrusive igneous rocks differ in formation from intrusive igneous rocks?
extrusive - forms when magma solidifies at surface intrusive - forms when magma crystallizes at depth
How does an exfoliation dome form?
from sheeting
what are the four types of mechanical weathering?
frost wedging, salt crystal growth, sheeting, biological activity
how does an atom become a negative ion?
gaining a electron
what are two good examples of polymorphs?
granite, diamond
what are four basic compositional groups of igneous rocks? list in order from highest to lowest silica content
granitic, andesitic, basaltic, ultramafic
the more silica in magma, the _____________________
greater its viscosity
what are the four agents that drive metamorphism?
heat, confining pressure, differential stress, chemically active fluids
what is the most destructive kind of magma?
highly viscous magma
what type of magma must erupt to produce an eruption column?
highly viscous magma
melting occurs at progressively higher temperatures with ___________.
increased depth
As the silicate structures change from isolated silica tetrahedra to chain and then framework silica tetrahedra, the ratio of silicon atoms to oxygen atoms __________.
increases
how does the formation of biochemical processes differ from the formation of inorganic processes
inorganic process uses evaporation and chemical activity, organic process uses water-dwelling organisms
what is the process of crystallization?
it occurs when particles dissolved in a liquid or a melt solidify and form crystals
what is meant by the statement "every metamorphic rock has a parent rock"?
its mean the rock from which the metamorphic rock was formed
Why are lava flows typically finer grained than intrusive igneous rocks?
lava flows cools quickly on surface of earth so mineral grains do not have time to grow
how do light-colored igneous rocks differ from dark-colored igneous rocks?
light colored rocks are felsic and dark colored rocks are mafic
what is one rock that exhibits non foliated texture?
limestone
how do you distinguish dolostone and limestone?
limestone fizzes when hydrochloric acid is dropped onto it
what are three components of magma?
liquid - melt, solid - crystals of silicate minerals, gaseous - volatiles
what is an effective way to distinguish orthoclase and plagioclase feldspar?
look for striations
how does an atom become a positive ion?
losing an electron
what are two basic categories of weathering?
mechanical, chemical
which of the following each material can be used to make interpretations about the nature and composition of the interior of the earth? a. meteorites b. diamond-bearing kimberlite pipes c. slivers of crustal and mantle rocks exposed at the surface d. meteorites, kimberlite pipes, and slivers of crustal and mantle rock e. groundwater and vapors in geothermal systems
meteorites, kimberlite pipes, and slivers of crustal and mantle rock
what distinguishes mineral species and mineral variety?
mineral variety is a subdivision of mineral species
when did the Greeks begin writing about the Earth?
more than 2,300 years ago
Felsic magmas/lavas are __________ viscous than basaltic magmas/lavas because they contain a __________ percentage of silica.
more, higher
what are five characteristics of a mineral?
naturally occurring, solid substance, orderly crystalline structure, definite chemical composition, generally inorganic
is color a good way to distinguish between orthoclase and plagioclase feldspar?
no
which sedimentary rock texture is associated with detrial rocks?
nonclastic
where do pillow lavas form?
ocean floor
what is the most common element in the continental crust?
oxygen
what are two common products in oxidation?
oxygen, iron
what are the 8 most common elements in the earths surface?
oxygen, silicon, aluminum, calcium, sodium, iron, magnesium, potassium
what is the difference between pahoehoe flows and aa flows?
pahoehoe flows are hotter than aa flows
what are the five basic controls of soil formation?
parental material, climate, plants and animals, time, topography
what does water and volatiles trigger when they lower the melting temperature of hot mantle rock?
partial melting
Why is heat considered the most important agent of metamorphism?
provides energy needed to produce the chemical reaction that result in the recrystallization of existing minerals
what is the difference between pumice and scoria?
pumice is light in color and less dense than scoria
what are five volcanic hazards?
pyroclastic flows, lahar, tsunamis, aviation, respiratory health
you are attempting to identify a mineral. you determine that it does indeed have cleavage. therefore, your mineral cannot possibly be ___________.
quartz
what minerals are the most abundant in detrial rocks?
quartz, clay
How is regolith different from soil?
regolith does not contain organic matter, water, and air
what is a difference between granite and rhyolite?
rhyolite deposits are less common and voluminous than granite
order the magmas from most silica rich to least silvia rich based on composition
rhyolitic (felsic), andesitic (intermediate), basaltic (mafic)
how do rocks differ from minerals?
rocks are aggregates of minerals
what are three ways in which mineral grains in a rock develop a preferred orientation?
rotation of platy mineral grains, recrystallization that produces new minerals, flattening spherically shaped grains
what is the definition of planetary differentiation?
separation of materials based on density
what are three types of detrial sedimentary rocks?
shale, sandstone, conglomerate
the largest volcano in the world is a ____________.
shield volcano
what are igneous rocks mainly composed of?
silicate minerals
why is color not always a useful property in mineral identification?
slight impurities give minerals a variety of tints
why do some minerals break along one or more specifically oriented planes while others do not?
some minerals have weak bonds in some directions and strong bonds in others
what is the single most characteristic feature of sedimentary rocks?
strata
why is texture an important soil property?
strongly influences the soil's ability to retain and transmit water and air
what are two criteria igneous rocks can be classified by?
texture, mineral composition
what region on earth has the largest concentration of composite volcanoes?
the pacific plate
what are two sources of energy for the earth system?
the sun and heat from the earths interior that powers internal processes
how do crystals in pegmatites grow so large?
they are a consequence of a fluid-rich environment that enhances crystallization
what is the significance of valence electrons?
they can be transferred to other atoms to form chemical bonds
in what way does tuff and volcanic breccia differ from other igneous rocks?
they do not imply mineral composition
how do geologists use index materials?
to distinguish among different zones of regional metamorphism
what is a useful way to identify mineral calcite?
transparent calcite over printed text makes letters appear twice (double refraction)
the more _____________ the material, the greater its _______________ to flow
viscous, resistance
what would cause sediments to be poorly sorted?
when there is a wide range of different sized particles
