Geology

minerals

regardless of their size, most rocks are made up of

be generally inorganic in origin

minerals must be solid, have an orderly atomic structure, have a recognized chemical composition, be naturally occuring, and

minerals must occur naturally

A scientist creates diamonds using high-pressure laboratory experiments. These diamonds are not considered minerals because which of the following requirements has been violated

ice

which of the following is a mineral

glass has a disorderly atomic structure

why is glass not considered a mineral

quartz

the principle mineral used in making glass

What are the criteria to define a mineral

orderly internal structure, well defined chemical composition, inorganic, naturally occuring

quartz

is a mineral

mineral

chemical composition, orderly crystalline structure, naturally occuring

rock

solid, naturally occurring, cohesive substance composed of minerals or mineral-like materials.

true

a rock can be composed of almost entirely one mineral

false

there can be no variation of mineral composition in order for the substance to remain the same mineral

number of protons

determines the chemical and physical properties of an atom

18

an isotope has 8 protons, 10 neutrons, and 8 electrons. what is the atomic mass of this isotope?

elements

are groups of the same kinds of atoms that cannot be broken down into other substances by ordinary chemical means

+1

charge of a single proton

true

an atom is the smallest particle that cannot be split

what is an iron?

an atom that had more or fewer electrons than it should

8

according to the octet rule, atoms tend to gain, lose, or share electrons until the are surrounded by ___ valence electrons

covalent bond

chemical bonds created by sharing a pair of electrons between atoms

ionic bond

complete transfer of electrons between atoms

crystal form

the external expression of a minerals orderly internal arrangement of atoms is referred to as

property of cleavage reflects

mechanical breakage along planes of weakness within the mineral

quartz

in the field, you find an unidentified mineral that is clear, exhibits conchoidal fracture, and can be scratch glass. this mineral is most likely:

calcite

while studying some sedimentary rocks in your field area, you find a mineral with rhombohedral cleavage that reacts with hydrochloric acid. what mineral is this:

fractional crystallization

crystallization of part of a magma leaving behind melted rock with a different composition from the original magma

why does magma composition change during fractional crystallization?

different elements in the magma form crystals at different rates, leaving behind more of the unused elements

magma depleted in iron

what type of magma would you expect to see after crystallization of minerals containing significant amounts of iron

crystals are denser than magma

represents the relationship between magma and crystals formed from that magma

metamorphism

what is not one of the three primary ways minerals can form?

3 primary ways minerals can form

crystallization of molten material precipitation biological processes

mineral cleavage…

,….

mineral color….

…..

mineral habit….

…..

mineral hardness…

…..

false

all minerals have cleavage

false

color is a reliable identification technique for minerals

trace elements

influences a minerals color

law of constancy of interfacial angles

states that the angles between equivalent faces of crystals of the same mineral are always the same

false

polymorphs are minerals that will have two identical mineral structures, but different chemical compositions

silicon and oxygen

which of the following pairs of elements are the most abundant in the continental crust?

sulfur

only eight elements make up the vast majority of rock-forming minerals. which of the following elements is not one of the eight?

silicates

are the mineral class that accounts for more than 90% of the Earths crust

silicon-oxygen tetrahedron

which of the following is a basic structural component of the most common mineral group?

magnesium and iron

ferromagnesian minerals are those that contain a great deal of

false

quarts has only one color

true

ferromagnesian minerals have a higher specific gravity than nonferromagnesian minerals

what three components make up most magmas?

liquid portion, solid portion, gaseous portion

silicates

which mineral class makes up most igneous rocks

upper mantle

peridotite is the main constituent of which part of the Earth

quartz and potassium feldspar

which two minerals define a felsic comomposition

igneous composition too MAFIC

~50%

igneous composition too FELSIC

~70%

geological definition of texture

size and shape of mineral grains in the sample

pumice

is a felsic igneous rock with a meringue-like vesicular texture created by small shards of volcanic glass

igneous composition of OBSIDAN

felsic

igneous composition of PUMICE

felsic

extrusive equivalent of GRANITE

rhyolite

introduction of water

at a subduction zone, melting is triggered by

higher melting points are determined by higher pressures

which is the following statements best describes the relationship between pressure and melting point in the earths interior

geothermal gradient

what is the term used to describe increased temperature with depth in the earth

how can magma body change its composition?

crystal setting magmatic differentiation magma mixing assimilation

bowens reaction series

describes how an entire suite of silicate minerals can form from a single basaltic magma as it cools and crystallizes

magmatic differentiation

describes the formation of one or more secondary magmas from a single parent magma

olivine

which mineral on the bowens reaction series will be the last to melt if an igneous rock is heated

quartz

which mineral on the bowens reaction series will be the first to melt if an igneous rock is heated

which process is thought the generate most felsic magmas?

heat from basaltic magma partially melting overlying crust

sill

a tabular, concordant pluton that is nearly horizontal and forms when magma exploits a weakness between sedimentary layers

laccolith

a mushroom-shaped pluton that forms by injecting magma between sedimentary strata, forcing the upper layers to arch upward

increase in temperature

would decrease the viscosity of magma

change in the composition of gasses being released

which of the following indicates that a volcanic eruption could be imminent?

magma

molten rock that contains dissolved gases and some crystals

viscosity

a materials resistance to flowing

false

the more silica in magma, the lower the viscosity

Aa flows have sharp, jagged edges

which of the following is a feature of an aa flow

basaltic

which of the following lavas make up 90% of the total volume of lava on Earth?

Pyroclastic materials

is pulverized rock, lava fragments, and ash erupted from a volcano

vesicles

what is the name of the small holes created by gas bubbles on the surface of scoria?

basaltic

in order to cover such large expanses of seafloor, shield volcanoes erupt_____ lava

cinder cones

which volcanoes have flanks with the steepest angle of repose?(between 30 and 40 degrees)?

false

most cinder cones have eruptive phases that last for centuries

silica

lavas erupting from composite cones are generally_____ rich, making them very viscous

pacific

the ring of fire is a narrow zone of composite cone volcanoes rimming the _____ ocean

volcanic ash

which type of volcanic hazard can decrease global temperatures?

gravity

what is the driving force behind pyroclastic flows

which of the following is not a method of caldera formation?

collapse of summit of a cinder cone volcano after an effusive lava flow

low; high

basaltic magmas have a ____ viscosity, whereas rhyolitic magmas have a ___ viscosity

felsic

Lava domes are___

convergent plate boundries

which of the following geologic regions creates volcanic arcs?