GMU Geology 101 Test 1

Biotite Mica

Black, rich in Fe and Mg Cleaves in 1-D Has a density of 3.0g/cm3 mafic mineral

Covalent bonds

Bonds created by sharing electrons with other atoms.

Neptune

"Twin" of Uranus Many high clouds Dry ice!

Intrusive rock

(Igneous) Magma that solidifies below the surface

Extrusive rock

(Igneous) magma that cools on the surface Most terrestrial magmas consist of silicates The varying amounts of SiO2 and H2O control the density and viscosity

Calcite

CaCO3 Main mineral in limestone Hardness of 3 Effervesces in dilute HCl Perfect cleavage in 3 directions, not at right angles (rhombohedron) Non-silicate mineral

Dolomite

CaMg(CO3)2 CarbonateofCalcium and Magnesium Similar to limestone Non-silicate mineral

Gypsum

CaSO4 * 2H2O Hardness of 2 Cleaves in one direction to form thin nonelastic plates Non-silicate mineral

Amphibole (Hornblende)

Chemically similar to pyroxene (except contains hydroxyl ions (OH-)) Minerals also cleave in 2 directions- but not at right angles mafic mineral

4 cleavage planes

Cleavage in four directions example: fluorite

Biosphere

Consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere.

Nature of Magma

Consists of three components: Liquid portion = melt Solids, if any, are silicate minerals Volatiles = dissolved gases in the melt, including water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)

valence electrons

Electrons on the outermost energy level of an atom

Clay minerals

Form at the earth's surface from erosion of other silicate minerals mafic mineral

Venus

Has no magnetic field, perhaps because of its slow rotation No satellites Most like the Earth in size, density and distance from the Sun Very high amounts of CO2

Mars

Huge canyons, volcanoes, dust storms, ice caps and dry riverbeds Only ~1/2 the diameter of Earth and Venus but twice the size of Mercury.

Mercury

Innermost planet Fastest in its orbit Otherwise, similar to the moon

Jovian Planets

Jupiter, Saturn, Uranus, and Neptune because they are gaseous

Earth

Just the right distance from the Sun for water to exist as a liquid, solid and a gas This makes our planet unique Continually changing from its interior as well Presence of water on Earth has enabled life to evolve- which has changed the composition of the Earth, especially the atmosphere

Muscovite Mica

K-Alsilicates Perfect 1-D cleavage felsic mineral

Jupiter

Largest of the planets Most complex Emits more energy that it receives from the Sun Small rocky core 16 moons- and a faint ring! Similar to a mini solar system Does NOT tilt

Rocks

Maybe composed of one mineral Often composed of multiple minerals

terrestrial planets

Mercury, Venus, Earth, Mars (and the moon)

Polymorphs

Minerals with the same composition but different crystalline structures

Non-silicate minerals

Minerals without Si or O2

Meteorites

Mini-asteroids of fragments of large asteroids that have fallen to the earth Four main compositions are known; Nonmetallic chondrites -91% - Archean Metallic -6% - Fe & Ni Carbonaceous chondrites -2% - ~5% organic compounds Stoney irons -1%

Feldspar

Most common mineral group ~50% of the crust 2 major groups K-feldspar [KAlSi2O8] (commonly pink) Plagioclase feldspar [NaAlSi3O8-CaAl2Si2O8] (variable colors)

Halite

NaCl Easily identified by taste Cleaves in 3directions in right angles Easily dissolvable (Common table salt) Evaporite

Core

Outer Core - Liquid layer Inner Core - Solid core

convergent tectonic plates

Plates that move towards each other

Mountain belts

Regions of the continents where the rocks have been highly deformed by enormous forces. These belts usually lie along the edges of the continents.

Moon

Relatively small No atmosphere, hydrosphere or biosphere Each is covered with craters which record the birth of the solar system ~4.7bya.

Silicic

Rocks, Magmas, or Melts that contain large concentrations of Silica, manifest in Granite or Rhyolite; viscous and cooler forms felsic minerals

Uranus

Same density as Jupiter but much smaller Only planet to lie on its side 9 rings and 15 moons

Saturn

Slightly smaller than Jupiter Also emits more energy -but not as much 18 moons Tilted at 27 degrees Of course, there are those famous rings! - Hundreds of them!

Pluto

Smallest "planet" Not really a planet at all, part of the Kuiper belt Similar to terrestrial planets Has an atmosphere and exhibits seasonality Also lies on its side Has one large moon!

Atom

Smallest particle of an element

Octet rule

States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons

Geosphere

Surface of the earth to the center of the planet ~6400km Largest of all the "spheres" Soil -connected to all the sections.

Quartz

The last mineral to form Hardness of 7 Conchoidal fracture Glassy luster felsic mineral

Crystallization

The process by which atoms are arranged to form a material with a crystal structure

Crust

The thin and solid outermost layer of the Earth above the mantle Two different types: - Oceanic - Continental

Transform Tectonic Plates

1A type of fault whose relative motion is predominantly horizontal, in either a sinistral (left lateral) or dextral (right lateral) direction. It results in friction, which can cause Earthquakes, Islands, and Volcanic Eruptions.

atmosphere

78% N2 and 21% O2 Divided into: - Troposphere - Stratosphere

Silicate Minerals

95% of the crust Silica and Oxygen form together in a complex ion in the shape of a tetrahedron. Form in varying shapes Most of the earth's upper crust and upper mantle are composed of Fe, Mg, Na, Ca, K, and Al combined with Si and O2.

Uniformitarianism

A principle that geologic processes that occurred in the past can be explained by current geologic processes

Catastrophism

A principle that states that geologic change occurs suddenly

Kuiper Belt

A region of the solar system that is just beyond the orbit of Neptune and that contains small bodies made mostly of ice

Lithosphere

A rigid layer made up of the uppermost part of the mantle and the crust.

Mohs hardness scale

A scale ranking ten minerals from softest to hardest; used in testing the hardness of minerals

divergent tectonic plates

A tectonic boundary where two plates are moving away from each other and new crust is forming from magma that rises to the Earth's surface between the two plates .It can also result in trenches and river formation.

Cryosphere

A term referring to all water that is temporarily frozen in polar ice caps, snow, permafrost, and glaciers

Hydrosphere

All the water at and near the surface of the earth, 97% of which is in oceans

mafic minerals (Ma + Fe +...)

Another type of silicate High percentage of Mg and Fe Often dark in color and have higher densities The "dark" silicates.

Anions

negatively charged ions

Color

not a very reliable property to identify a mineral

8 most common elements in Earth's crust

oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium

Cations

positively charged ions

double refraction

property of transparent mineral that produces a double image of an object viewed through them

What are the main parts of an atom

protons, neutrons, electrons

specific gravity

ratio of a mineral's weight compared with the weight of an equal volume of water

Bowens Reaction Series

sequential, predictable, dual-branched pattern in which minerals crystallize from cooling magma The FeMg minerals form a discontinuous series and the feldspars form a continuous series.

Evaporites

subgroup of non-silicates Formed in specific environments -Shallow water -Inland water body -Warm temperature

Streak

the color of a mineral's powder

crystal form

the external appearance of a mineral as determined by its internal arrangement of atoms

Metallic bonds

the forces of attraction between the free-floating valence electrons and the positively charged metal ions

Atomic Number

the number of protons in the nucleus of an atom

Mass number

the sum of the number of neutrons and protons in an atomic nucleus

Cleavage

the tendency of a mineral to break along parallel planes of weakness

Ionic bonds

transfer of electrons

abyssal plain

very level area of the deep-ocean floor, usually lying at the foot of the continental rise

Asteroids

~1 million objects from 1 - 950 kilometers that mainly circle the sun between the orbits of the planets Mars and Jupiter They are irregular in shape and composition (both Si-rich and C- bearing)

Mantle

~82% of Earth's volume • Upper Mantle - Lithosphere - Asthenosphere - Transition zone • Lower Mantle

Rock Cycle

-Crystallization -Weathering/transporting -Lithification -Metamorphism -Melting

Energy levels

-Individual electrons move within regions around the nucleus -Each can hold a specific amount of electrons

Scientific Method

-Questions -Data Collection, observations, and experiments -Hypothesis -More experimenting and data collection -Theory -Scientific Law

felsic minerals (feldspar+silicate+...)

-Rich in Si (silicon) and Al (aluminum) -Represented by granites, feldspars and quartz -Have low densities and crystallize at low temperatures -The "light" silicates.

Silicate Shapes

-independent tetrahedron -single chain -double chain -sheet structure -three dimensional framework

Mineral Criteria

1. Occurs naturally as an inorganic solid 2. Has a specific internal structure 3. Has a specific chemical composition 4. Has specific physical properties 5. Minerals can be composed of one element or a combination of elements

Ion

A charged atom

conchoidal fracture

A curved fracture surface; looks like the inside of a clam shell

Olivine

Dark green with a glassy luster Density is 3.3g/cm3 A high temperature mineral Common in basalts, and in the upper mantle mafic mineral

Ocean ridges

The undersea mountain chains that are formed when magma oozes up and solidifies between tectonic plates that are moving apart.

Fracture

The way a mineral looks when it breaks apart in an irregular way

Luster

The way a mineral reflects light

Comets

Very low density and most are less than1 0 kilometers in diameter Often nicknamed "dirty snowballs", they are mainly composed of ice and stony particles If one approaches the sun the solar-wind produces the familiar gaseous tail. They originate in the outer most solar system, where ice and dust are thought to orbit in the Oort Cloud which consists of material blown from the inner solar system 4-5 byr ago by the solar wind.

tetrahedron

a geometric solid having four sides that are equilateral triangles

Gemstones

a hard, colorful mineral that has a brilliant or glassy luster

shield

a large area of relatively flat land made up of ancient, hard rock

Hardness

a measure of the ability of a mineral to resist scratching

cleavage plane

a surface along which a mineral cleanly splits

Pyroxene

any of a large class of rock-forming silicate minerals, generally containing calcium, magnesium, and iron and typically occurring as prismatic crystals Often dark green to black 2 directions of cleavage that meet at right angles mafic mineral

3 cleavage planes

cleavage in three directions at 90º example: Halite cleavage in three directions not at 90º example: Calcite

2 cleavage planes

cleavage in two directions at 90º example: Feldspar cleavage in two directions not at 90º example: Hornblende

Oxides

compounds that contain oxygen and an element other than silicon

Basaltic

dense, dark-colored igneous rock formed from magma; rich in magnesium and iron and poor in silica; liquid and very hot forms mafic minerals

effervescence

dripping acid on rocks to see if they bubble

igneous rocks

formed when magma cools beneath Earth's surface or when lava cools at Earth's surface; forms in or around volcanoes; requires heat Tells us the history of the earth