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GMOA Notes

From Science Olympiad Student Center Event Wiki

This is a work in progress, and eventually I will finish it. Sorry it is taking so long.

These are notes that cover Geology, Meteorology, Oceanography, and Astronomy.

1 Introduction
2 Minerals
3 Mineral Key
4 Igneous Rocks and Volcanoes

Introduction

Earth's four spheres

Hydrosphere - dynamic mass of liquid that is always on the move

Oceans - the most prominent feature of the hydrosphere
- 71% of Earth's surface is covered by ocean which is 97% of Earth's water
- Only 3% is fresh water - streams, lakes, glaciers and underground supplies
Water Cycle - constantly recycles water

Atmosphere

Provides us with the air we breath
Protects us from the sun's intense heat and radiation
Protects us from space

Biosphere

Includes all life on Earth
Interacts and influences the other 3 spheres

Lithosphere

Earth's rigid outer layer called the crust and the upper mantle called the asthenosphere
Solid earth consists of 4 layers:
- core
  - inner, solid core
  - outer, liquid core
- mantle
- lithosphere
Divisions of Earth's surface
- continents
- ocean basins

Sciences

Sciences involved in better understanding the earth integrate chemistry, physics, and biology into the following sciences:

Meteorology - the study of:

the atmosphere
weather and climate

Geology - the study of the Earth, and is broken into

Physical geology
- minerals
- rocks
- Earth processes - mountain building, earthquakes, volcanoes, etc.
Historical geology - Earth's origin and it's past
- physical
- biological

Oceanography - study of the Oceans

Composition and movement of seawater
Seafloor topography and sea life

Astronomy - the study of the universe

Earth is a tiny object in a vast universe
to understand Earth helps us to understand other planets and vice versa

Resources and Environmental Issues

Environment

Physical environment (abiotic)
- water
- air
- soil
- rock
Biological - living environment (biotic)

Resources

Important environmental concern
Include:
- water
- soil
- minerals
- energy
Two broad categories of resources
- Renewable resources
  - can be replenished
  - Examples: plant (lumber) and wind energy
- Nonrenewable Resources
  - Fixed quantities
  - Examples: fuels and metals

Environmental Problems

Local, regional, and global
Human-induced and accentuated
- Urban air pollution
- Acid rain
- Ozone depletion
- Global Warming
Natural Hazards
- Earthquakes
- Landslides
- Floods
- Huricanes
World population pressures - in 30 years population increased from 4 to 7 billion
- US makes up 6% of that but uses 30% of the annual mineral and energy resources
- Alternate energy sources needed

Scientific Inquiry

Scientific Inquiry - scientific knowledge is gained through the following systematic steps called the scientific method, (PI-HE-RAC)

Gather facts through observation then ask why?

Problem - state the problem
Information about the problem
Hypothesis (untested best guess as to why)
Experimentation
Record and Analyze results
Conclusion - accept or reject hypothesis

Goal of science is to discover patterns in nature and use knowledge to predict what will happen under certain circumstances

Theory - tested and confirmed
Law - no known deviations have ever been found

Minerals

A mineral is a naturally occurring crystalline solid with a definite but not fixed chemical composition and ordered atmomic arrangement.

Chemistry and Mineral Terms

Chemistry Terms:

Chemical Property - characteristics of a material, which depends upon how the material reacts with other materials

Periodic Table - list of all known elements

Element - matter made up of atoms that are essentially all the same and cannot be subdivided by ordinary chemical methods

Atom - smallest part of an element

Nucleus - central part of an atom made up of protons and neutrons

Protons - subatomic particles with a positive charge

Electrons - subatomic particles with a negative charge

Neutrons - subatomic particles with a charge of 0

Atomic number - the number of protons in an atom (above element symbol on periodic table)

Atomic mass - the number of protons plus the number of neutrons (below element symbol on periodic table)

Isotope - change in the number of neutrons in an atom. Example, and isotope of sodium may have 10 or 12 neutrons

Electron Configuration - how the electrons are arranged around the atom in energy levels
- 1st energy level has 2 electrons
- all other energy levels have 8 electrons

Ion - change in the number of electrons
- Atoms are most stable with 8 electrons in the outer energy level
- Will share, lose, or gain electrons to achieve this

Ionic bonding - transfer of electrons
- example - Sodium and Chlorine

Lewis Electron Dot Structure - Short hand for showing "chemistry" activity in the outer level by showing the number of electrons in the outer energy level

Covalent bonding - sharing of electrons. VERY STRONG BOND
- example - bond between Hydrogen and Oxygen

Metallic bonding - electrons do not belong to any particular nucleus, they float between nuclei
- example - two metals touching for a long time can "weld" to each other by metallic bonding. You can increase the speed of this by adding heat.

Mineral Terms:

A mineral is a naturally occurring crystalline solid with a definite but not fixed chemical composition and ordered atomic arrangement
- Size of the ion is important because ions that are within 10% of the same size may be substituted in many minerals. This is why minerals of the same type have different chemical compositions.
  - examples - Si,Al; Fe,Mg; Na, Ca

The main elements in the Continental Crust
Element	% by Weight
Oxygen, O	47
Silicon, Si	28
Aluminum, Al	8
Iron, Fe	6
Calcium, Ca	4
Sodium, Na	3
Magnesium, Mg	2
Potassium, K	2

Mineral formation
- Melting - Volcanic activity
- Evaporation - Salt water: Halite, Gypsum
- Biological activity - sulfur producing bacteria
- Oxidized - comes into contact with oxygen: Limonite
- Leached - as water moves through the soil it dissolves elements. A leech line forms due to mineral formation where the water stops: bauxite
- Metamorphic processes - formed by heat and pressure. Examples: graphite, chlorite, diamonds. Alters chemical composition and structure, called recrystallization

Mineral Types
- Native minerals - contain one element
  - examples - graphite, C; Copper, Cu; Sulfur, S
- Sulfides and Sulfates - contain Sulfur and other elements
- Silicates - contain silicon and other elements
- Oxides - contain oxygen and other elements
- Carbonates - contain CO and other elements
  - will effervesce in the presence of an acid
- Phosphate - contains PO and other elements

Physical Property - is controlled by the chemical properties of a material...how its bonded can determine the hardness and the type of impurities that are present in its change in color

Color - reflected light; very poor indicator of the true color due to impurities

Streak - true color of the mineral found by powdering it. This is found by scratching the mineral across a streak plate.

Hardness - the resistance to scratching

Moh's Hardness Scale
Hardness	Mineral	Common Tool
1	Talc	Fingernail
2	Gypsum	Fingernail
3	Calcite	Penny
4	Fluorite	Nail
5	Apatite	Nail
6	Orthoclase	Glass
7	Quartz	Streak Plate
8	Topaz
9	Corundum
10	Diamond

Cleavage - the tendency for a mineral to break along flat smooth planes that reflect light
- This is controlled by a weakness in structure, may break where bonds are longer or fewer
- predictable pattern, not random
  - 1 perfect - stacks like sheets of paper, example: mica
  - 2 perfect - break in two directions and is very clear, example: calcite
  - 3 cubic - breaks into perfect cubes, example: halite
  - none - no repeating faces
  - conchoidal fracture - concentric circles are around breaks, irregular fracture pattern, example: quartz

Magnetism - minerals that contain iron and are polarized, example: magnetite

Taste - how they taste: bitter, sweet, salty

Luster - appearance
- metallic - look like metal
- nonmetallic - look earthy

Density = mass/volume

Specific gravity - how heavy something is in air compared to how heavy it is in water

Radioactivity - the breakdown of atoms in the nucleus

Mineral Key

This is not a full table of minerals.

Mineral Key
Hardness	Color	Streak	Cleavage	Remarks	Name	Composition
1 to 1.5	Steel Grey to Iron Black	Black to Grey	1 Perfect	Metallic Luster, Greasy feel-marks paper, Use Pencil Lead	Graphite	C
2.5	Blue-Black to Lead Grey	Grey-Black	3 Cubic	Cubic cleavage, High Specific Gravity, Metallic Luster, Use-Lead Ore	Galena	PbS
2 to 2.5	Reddish	Red	2 perfect	Usually Granular, Distinguished by Red Streak, Use-Mercury Ore	Cinnabar	HgS
1 to 1.5	Blue-Black	Greenish Black	1 perfect	Metallic Luster, Greasy feel, use-Molybdenum Ore	Molybdenite	MoS
2.5 to 3	Black to Dark Green	Brownish Black, Green Black to Colorless	1 perfect	Perfect cleavage 1 direction, commonly in stacks or sheets--one on the micas	Biotite	K(Mg,Fe)₃(AlSi₃O₁₀)(OH)₂
2 to 2.5	Colorless	Colorless	1 perfect	Perfect cleavage 1 direction, commonly in stacks	Muscovite	KAL₂(AlSi₃O₁₀(OH)₂
1	White or Grey	White to Greenish White	1 perfect	Greasy feel, non-metallic luster, use-talcum powder	Talc	Mg₃Si₄O₁₀(OH)₂
2	Colorless to White	White to Colorless	1 perfect	Perfect cleavage i direction, may be fibrous, use-sheet rock	Gypsum	CaSO₄+H₂O
2 to 2.5	Green	Green	1 perfect	Feels greasy, use-fertilizer	Chlorite	(Mg,Fe)₃(Si,Al)₄O₁₀(OH)_2S/sub>
1 to 2	White	White	None	Absorbs water, greasy feel, one of the clay minerals, use-kaolinite	Kaolinite	Al₂Si₂O₅(OH)₄
1.5 to 2.5	Yellow	Yellowish White	None	usually granular, streak smells like sulfur, use-chemical industry	Sulfur	S
1 to 3	Brown, Yellow Orange to White	Yellowish to White	None	Rounded grains, usually clay like, use-aluminum	Bauxite	Al(OH)₃
3	White to Colorless	Colorless	3 perfect not at right angles	effervesces with HCl, shows double refraction, use-calcium	Calcite	CaCO₃
3	Gray to colorless	Colorless	3 perfect hard to see	A type of calcite, effervesces with HCl, usually massive	Aragonite	CaCO₃
2 to 2.5	Colorless to White	Colorless to White	3 perfect at 90 degrees	Tastes salty, soluble in water, use-salt	Halite	NaCl
1.5 to 5	Yellow, Brown, Orange-Brown	Rusty yellow, Brown-red	None	Characterized by rusty streak, mars mineral, use-iron	Limonite	FeO
2.5 to 3	Copper Red, Green Tarnish	Copper Red	None	Metallic Luster with distinctive streak, use-copper	Copper	Cu
3.5 to 4	Bright Brassy Yellow	Green yellow, Brassy brown	None	Distinctive color, metallic luster, use-minor copper ore	Chalcopyrite	CuFeS₂
3.5 to 4	Brown-yellow, Orange-black	Yellow	6 directions difficult to detect	gives sulfur smell when powdered on streak plate, use-zinc	Sphalerite	ZnS
3.5 to 4	Azure Blue	Light Blue	1 perfect	Commonly found with green malachite	Azurite	Cu₃(CO₃)₂(OH)₂
4	Light Purple or Yellow	Colorless	3 perfect difficult to see	Effervesces with HCl when powdered	Dolomite	CaMg(CO₃)₂
4 to 5	Dark to Light Green	White	None	Chief source of asbestos	Serpentine	Mg₂Si₂O₅(OH)₄
5	Green or Brown	White	1 poor	use-making fertilizer	Apatite	Ca₅(PO₄)₃(F,Cl,OH)
5 to 6	Pale Yellow to White, Green	Colorless	Conchoidal Fracture	Characterized by pale yellow color, precious opal, shows play of colors	Opal	Si)₂+H₂O
5 to 6	Black	Dark grey to colorless	2 perfect at 60 and 120 degrees	one of amphibole group, cleavage makes it appear to be in layers	Hornblende	(Ca,Na)_2,3(Mg,FeAl)₅Si₆(Si,Al)₂O₂₂
6 to 6.5	Steel Gray or Red Brown	Red Brown	None	Forms ranging from earthy to specular, use - iron ore	Hematite	Fe₂O₃
5.5	Shiny Black to Brown	Dark Brown	None	Use - chromium ore	Chromite	FeCr₂O₄
5.5 to 6	Black	Black to Dark Gray	None	Magnetic, Use - Iron Ore	Magnetite	Fe₃O₄
6	Orange-pink	White to Colorless	2 directions 90 degrees to each other	Common rock forming mineral, use - potassium	Potassium Feldspar	KAlSi₃O₇
6	Pearly White to Gray	White	2 perfect	Crumbly elongated crystals, use - ceramics	Albite	NaAlSi₃O₈
6	Dark Green to Black	Gray to White	2 at 90 degrees	very common mineral	Augite	(Fe,Mg)SiO₆
6 to 6.5	Dull Brass Yellow	Green to Brown Black	None	Fools Gold, use - gold and copper association	Pyrite	FeS₂
6 to 6.5	Blue gray to Black	White to Colorless	2 good at 90 degrees	very common mineral	Plagioclase Feldspar	(Na,Ca)Al₂Si₂O₈
6.5 to 7	Green to Brown	Colorless	1 Perfect	Characterized by olive green color, use - peridot	Olivine	(Mg,Fe)₂SiO₄
6.5 to 7.5	Dark Red	White	Conchoidal Fracture	often found in formed crystals in metamorphic rocks, use - garnets	Garnet	FeAl₂Si₃O₁₂
7	Cleat to White, Pink, Purple, or Blue	White	Conchoidal Fracture	extremely common mineral, use - glass and gems	Quartz, Rose quartz, and Amethyst	SiO₂
7	Light Grey to Beige	None	None	Same as flint, will spark streak plate, use - flint and arrowheads	Chert	SiO₂
7.5 to 8	Blue-Green, Green-yellow	None	1 poor	usually found in hexagonal crystals, use - emeralds	Beryl	Be₃Al₂(Si₆O₁₈)
8	Clear, Pink, Yellow, Brown to Blue or Green	None	1 perfect	use - topaz gems	Topaz	Al₂2SiO₄(F,OH)₂
9	Red-Brown	None	None	forms by hexagonal parting, use - gems (rubies and saphires	Corundum	Al₂O₃

Igneous Rocks and Volcanoes

Rock Cycle

the rocks of the crust are classified into 3 types according to their origin
Two of the three types are formed by processes deep in the earth's crust and tell us about conditions within the crust
- There are:
  - Igneous rocks - solidify from a melt or magma. If it cools fast small crystals form, if it cools quickly large crystals form
  - Metamorphic rocks - pre-existing rocks that are changed by heat and pressure within the crust.
  - Sedimentary rocks - weathered rock fragments of older rocks deposited in layers near the earth's surface by wind, water, or glaciers then cemented together by various agents. Records conditions on the Earth's surface.
- the interactions among the forces that produce these three rock types can be illustrated by the rock cycle.

The Rock Cycle [1]

Igneous Rocks

formed by the crystallization of magma
- magma is a natural, hot melt composed of a mutual solution of rock forming minerals (mainly silicates) and some volatiles (maybe steam), that are held in a solution by pressure. Magma probably originates near the bottom of the crust.
- magma that reaches the surface before solidifying is called lava.
two types of igneous rock
- - extrusive - reach the surface, small crystals, are called volcanic rocks, and cooled on the surface
  - intrusive - doesn't reach the surface, large crystals, called Plutonic rock, cooled below the surface

Volcanism - Volcanic Activity

Volcanoes are important because they provide clues about the earth's inaccessible interior.
Studying magma, gases and rocks we can determine chemical conditions, temperatures, and pressures within the crust and mantle.
Two factors control the violence of volcanic eruptions:
- The amount of gas in the lava or magma - the greater the amount of gas, the more violent the eruption.
- Viscosity - the resistance to flow, this determines how easily the gas escapes.
  - Two factors influence viscosity:
    - Temperature
    - Silica Content
Gases - most of the gas released from a volcano is steam, which is water vapor. The other gases that are released are Hydrogen Sulfide, Carbon Dioxide, and Hydrochloric Acid.
Rocks - chemical analysis shows that silica is the most abundant component in most volcanic rocks.
- The amount of silica can vary from 45% to 65%. This accounts for the difference in the appearance, mineral content, and behavior of the parent lava.
- Mafic rocks are silica poor (45% or less silica) and are typically dark in color. The parent lava has a low viscosity. The minerals included in these rocks are augite, olivine, chromite, and magnetite, which make up dark colored rocks. The most common mafic rock is basalt. The lava tends to flow easily (hotter), not as viscous, and is low in silica.
- Felsic rocks are silica rich (65% or more silica). The minerals included are quartz, potassium feldspar, and muscovite, this produces light colored rocks. The most common felsic rock is granite. High in silica, very viscous and explosive.
- Intermediate rocks have a chemical composition between mafic and felsic. They are medium to dark grey in color. Andesite is the most common. Lava is sluggish and explosive.

Volcano Types

There are three types of volcanoes that differ in size, shape, and composition.
The three types are:
- Shield volcanoes - mafic in composition, very fluid and nonexplosive magma. The form a broad gently sloping cone (looks like a shield), and are the largest volcanoes on the planet.

This image is from [2]

- - Hawaiian Islands - have quiet eruptions, basalt lava flows from central vent. They are an example of intraplate volcanism, and have formed over a hotspot.
  - Two types of basalt flows:
    - Aa - blocky lava that looks like rubble, cools quickly.
    - Pahoehoe - ropy lava that looks smooth, cools slower than aa.

- Cinder Cones - very steep slopes of loose rock fragments ejected from the central vent. They are the smallest type of volcano and erode easily. Mainly made up of pyroclastic material. Can be found on shield volcanoes.
  - Pyroclastic material or tephra can be any size and is classified by size.
    - Dust, ash - finest particles
    - Cinders - are 2-4mm in size
    - Bombs and blocks - molten blobs become streamlined during flight, solidify, and fall to the ground to form a lens shaped pyroclast.
  - These erode easily and can be found on shield volcanoes.

Cinder Cone Source

- Composite Volcanoes - also called stratovolcanoes, are made up of alternating layers of andesitic lava and ash. They are the most explosive type of volcano.
  - Lava is very viscous and is felsic in composition which causes the vents to be blocked easily.
  - Plugs cause gas pressure to build up until the pressure is greater that the plug and an explosion results
  - Not as steep as a cinder cone volcano
  - Very violent eruptions
  - Found along converging plate boundaries, which accords to the Theory of Plate Tectonics

Composite Volcano Diagram Source[3]

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