Geology 1.txt

• observation
• hypothesis
• test; retest or revise
• peer review

Assembling a large object by combining smaller fragments together.

When earth was 70% of its current size it was hit by a mars size impactor.

Separation of materials based on density. Heavier materials settle out to bottom, lighter ones rise to top.

Crust, mantle, core

Lithoshere, asthenosphere, mesosphere, inner core, outer core

Material behaviors of the earth's structure, i.e., rigid or ductile

Deformable

The rigid lithosphere floats on the ductile asthenosphere

Oceanic: thin and more dense & continental: thick and less dense

Testable explanation for what you have observed

mass/volume. Or, how much/how big.

Attractive force between masses

Heat transfer due to light.

Heat transfer due to movement of material.

Heat transfer due to contact.

4.5 billion years old

An object will float if an equal amount of mass of the supporting fluid is displaced.

Atoms of the same element that have different atomic masses. -- same # of protons but different # of neutrons

Number of protons in the nucleus. -- defines what element an atom is.

Number of protons + number of neutrons

The smallest unit of matter that has the properties of elements.

Atom with a charge imbalance. -- unequal # of protons and electrons.

Positively charged ion. -- more protons than electrons.

Negatively charged ion. -- more electrons than protons.

Outermost shell of electrons

An atomic bond between atoms in which valence shell electrons are shared. -- strongest atomic bond. -- water

An atomic bond formed by electrostatic attraction between ions of opposite charge when electrons are transferred. -- like NaCl, sodium chloride. -- two ions with opposite charge that hang out near eachother to appear charge balanced.

An atomic bond where electrons are freely shared among nuclei.

An atomic bond between the polar water molecule and other atoms/molecules.

A molecule that has an equal number of protons and electrons but an uneven distribution of electrons across the molecule.

Weak static bonds.

• 1. convergent ==> <==
• [ocean-continent, ocean-ocean, continent-continent]
• 2. divergent <==>
• [mid-ocean ridge, continental rift]
• 3. transform ^ v [L.A. vs S.F.]
• plates rubbing against each other

• protons (+)
• neutrons (+, -)
• electrons ( - )

number of protons in the nucleus; define what element an atom is

• adhesion; attraction to other substances
• cohesion; attraction to other H2O molecules
• heat capacity; amount of energy that must be added/removed to change temperature
• expands when frozen
• universal solvent; really good dissolver

• naturally occurring
• solid
• crystalline
• inorganic
• specific chemical composition

atoms are arranged in a set repeating order

• glue using intermediate atoms (Fe, Mg)
• polymerize by sharing a neighboring tetrahedron's oxygen

• olivine (100% glue)
• pyroxene
• amphibole
• mica
• feldspar
• quartz (100% polymerized)

• isolated
• single-chain
• double-chain
• sheet
• 3D network

• igneous
• sedimentary
• metamorphic

rocks that are cooled/crystallized from a melt

assembled fragments of other rocks, or, precipitate dissolved minerals; break or dissolve

alteration occurs in a solid state; cook, squish, or soak

• raise temperature; breaks bonds
• lower pressure; increases space between atoms
• add H₂O; molecular home-wrecker, lowers melting point

• glassy; lava cooled too rapidly for crystals to form
• vesicular; magma cooled too rapidly for gases to escape
• pyroclastic; "fire" "fragment"; rock assembled from erupted material

• measurement of a substance's resistance to flow
• high = thick, low = runny

• substances that are gases at magmatic temperatures
• H₂O
• CO₂
• form bubbles -- increase volume, lower viscosity

• cool slowly, deep underground
• cool using conduction
• plutonic

• cooled rapidly on the surface
• cools using radiation
• volcanic

• extrusive igneous texture
• very fine grained
• very small mineral crystals, need microscope to see

• intrusive igneous texture
• course grained
• minerals crystals seen with naked eye

• intrusive igneous texture
• extremely course grained
• crystals > 1cm

• intrusive igneous texture
• large perfect mineral crystals surrounded by finer grained ground mass
• 2 stages of cooling
• chemical limits on crystal size (based on varied quantities of ingredients

• continental caldera
• cinder cone
• flood basalt
• volcanic dome
• shield volcanos
• stratovolcano (or composite)

• ash fall
• ash flow
• mud flows (lahar)
• volcanic landslides
• tsunami
• lava flows
• gases

• low particle : gas
• lower density, gas rich mixture

• high particle : gas
• higher density

a sticky mixture of water and debris that is created when eruption products enter river channels or glaciers melt

• CO₂ + H₂O ==> H₂CO₃ (carbonic acid)
• Lake Nyos, Cameroon

• seismicity; harmonic tremors -- small M1-M2 EQ that occur when magma intrude rocks
• gas emissions; seeping through soil from magma
• surface temperature; water temperature of springs and lakes
• surface deformation

breakdown of rocks by physical or chemical means

transport of materials

• the breakdown of rocks purely by physical means
• SA:V
• the more mechanically weathered a rock becomes, the more likely it is to weather further

• frost wedging; water expands when frozen, exerts pressure on rocks
• crystal growth; water evaporates, leaves behind ions that form into crystals, exerting pressure on rocks
• mechanical exfoliation; rocks that form under pressure "peel apart" once the pressure is released
• tree roots and plants
• thermal expansion and contraction
• abrasion; rocks and sediment collide with eachother during transport

• changes chemical composition of rocks and minerals
• converts unstable rocks and minerals on the earth's surface to stable ones

• carries ions to reactions
• participates in reactions
• carries reaction products away

• dissolution
• oxidation
• hydrolysis

• ions (or ion groups) are carried away by water
• example -- halite, NaCl -ionic bond
• example -- limestone is CaCO_3; H₂O + CO₂ ==> H₂CO₃ (carbonic acid) H₂CO₃ dissolves limestone

• a mineral's ion combines with oxygen
• example -- Fe in mafic rocks
• example -- Fe²⁺ in minerals will oxidize to Fe₂O₃ (hematite) (rust)

• H⁺ or OH^- ions from water displace other ions in a mineral structure
• example -- hydrogen bonding will break feldspars down into clay minerals
• the type of reaction that is used to break down certain polymers

• detrital - broken fragments of other rocks
• chemical - previously dissolved minerals (crystalline)
• bioclastic - chunks of previously living organisms (bones, shells, teeth, etc.)

• water
• wind
• ice

• the volume of sediments that can be transported (how much)
• based on velocity; increase in V = increase in carrying capacity, decrease in V = deposition

• the largest size sediment that can be transported (how big)
• based on velocity; increase in V = increase in competence, decrease in V = deposition

• the separation of sediments based on size, shape and/or density
• poorly sorted, sorted, well sorted

• the process by which sediment becomes rock
• compaction or cementation

• pressure due to burial; overburden
• overlying pressure (weight) of sediments decreases volume, binding grains

• the pressure or stress imposed on a layer of soil or rock by the weight of overlying material
• pressure same in all directions
• squeezing out the empty spaces

• pore spaces (voids) will be filled in with cement minerals
• dissolved minerals precipitate out of solution and bind sediment grains
• calcium carbonate, silica, iron oxides

• based on grain size:
• boulder......
• gravel........
• pebble........ if angular = breccia; if rounded =conglomerate
• sand, sandstone
• mud, mudstone.......
• silt, siltstone..........
• clay, claystone........ if blocky or layered = shale

• based on composition and origin
• inorganic and biotic

• bedding
• ripple marks
• mud cracks

• aphanitic
• phaneritic
• pegmatitic
• porphyritic

• flat parallel layers of sediment
• caused by...
• changes in carrying capacity of the erosional agent
• changes in sediment composition

the sediment size decreases from the bottom of the bed to the top

• form due to dune processes
• the preserved slip faces found inside a dune

ripples from a current moving in one direction

oscillation; current goes back and forth

records wet/dry cycles

• rocks are recrystallized in the solid state
• original features of the rock are altered or obliderated

parent rock; original rock before metamorphism

• large scale metamorphism due to tectonic processes
• burial
• subduction
• mountain building
• == more even distribution of changes

• small scale changes due to direct contact with agents of metamorphism
• igneous intrusions
• lava flows
• hydrothermal fluids

• heat (temp)
• pressure (stress)
• fluids (H₂O)

10⁹

10⁶

10³

10^-2

10^-3

10^-6

10^-9