CHAPTER 1(Scientific Method) 2,3,6,7,15
REVIEW SHEET 1
Scientific Method (Chapter 1)
Steps of the scientific method from flow chart in power point
 observation
 hypothesis
 predictions and testing (experimentation)
 acceptance/modification of hypothesis
Attributes of the Scientific method (repeatable, unprejudiced, falsifiable)
The process used in following the scientific method
Why Intelligent Design is NOT considered a scientific theory by scientists
The accepted age of the Earth
Chapter 2 - Minerals
1. naturally occurring
2. inorganic
3. solid
4. definite chemical structure
Mineral Groups: Minerals grouped by their building blocks (silicates, carbonates, oxides, sulfides etc.)
Silicates- based on the silicate ion - SiO4.
Composed of a silicate ion surrounded by 4 oxygen atoms. Called the “silicon-oxygen
tetrahedron”.
Electrically unstable; has a charge of neg. 4. Must combine with various positive ions to
become stable. Note most of other abundant elements in the earth’s crust (Na, Ca, Fe, Mg, K,
Al) form positive ions and therefore combine easily.
In addition to positive ions, the tetrahedra link together across unshared oxygen to form
various structures (see p.33, fig 2.13)
-ferromagnesian: contains iron and magnesium (dark, heavy)
-nonferromagnesian: Al, K, Ca and Na, (light in color and weigh less)
Important nonsilicate minerals, p. 38.
-carbonates (calcite, dolomite)
-sulfates (gypsum
Minerals to identify: olivine, potassium feldspar, calcite, gypsum, mica group
Chapter 3 - Igneous Rocks
Origin of Igneous Rocks: 1. Plutonic, or Intrusive (remember Pluto, Lord of the Underworld!) - slow
cooling underground 2. Volcanic, or Extrusive - fast cooling above ground
Classification by texture: Dependent on origin
1. phaneritic - large crystals - plutonic
2. aphanitic - small crystals - volcanic
3. porphyritic - large crystals embedded in a fine-grained matrix - usually volcanic
4. glassy - cooled too fast to form crystals - volcanic
5. pyroclastic - formed from volcanic ash or pieces of lava- volcanic (ex- welded tuffs at the Nevada Test
Site to be used for nuclear waste storage
6. vesicular – filled with voids from escaping gas bubbles
Classification by Mineral Composition: Bowen’s Reaction Series- illustrates the relationship between
mineral crystallization and temperature
1. ferromagnesian minerals (olivine, pyroxene, amphibole, biotite mica)
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2. nonferromagnesian minerals (feldspar, muscovite mica, quartz)
Mineral Composition of Magma:
1. Magma differentiation - crystal formation and settling, due to differences in mineral melting points
(illustrated by Bowen’s Reaction Series)
2. Assimilation - Magma incorporates pieces of surrounding country rock with different mineral
composition
3. Magma mixing - 2 magma bodies with different mineral compositions combine
Classification by mineral content: dependent on mineral content of magma
1, ultramafic (composed of ferromagnesian minerals)
2. mafic (composed of ferromagnesian minerals and Ca plagioclase)
3. intermediate or andesitic (composed of ferromagnesian minerals, Ca-Na plagioclase and nonferromagnesian minerals
4. felsic (composed primarily of non-ferromagnesian minerals; less than 15% ferromagnesian.
rocks to identify: granite, rhyolite, basalt, gabbro, a porphyry
Chapter 15, Plate Tectonics
 Differentiation of the earth in layers by physical properties (state)
o inner core - solid iron
o outer core - molten iron
o mesosphere – mostly solid iron-rich silicates:
o asthenosphere - partially molten, “consistency of toothpaste”: This is the part of the
mantle upon which the tectonic plates ride.
o lithosphere – rigid solid; the material of the tectonic plates
 lithospheric mantle
 crust - silicates and other minerals; part of the lithosphere
 oceanic crust - relatively thin (3-5 miles thick) relatively dense, iron rich
 continental crust - relatively thick (up to 50 miles thick) less dense than
oceanic crust
 Alfred Wegener and Continental Drift
o fit of the continents
o similarities in rock type and structure
o fossil evidence
o paleoclimatic (glacial) evidence
o Wegener’s inability to propose a mechanism for continental drift
 tectonic plate boundaries and geographic examples of each (study the diagrams in the book and
be able to identify features such as rift zones, volcanic arcs etc.)
o divergent, sea floor spreading (mid-Atlantic ridge, East Africa Rift Valley)
o convergent
 oceanic-continental (coast of South America)
 oceanic-oceanic (island of the Far East)
 continental-continental (Himalayas in Asia)
o transform (San Andreas Fault)
 Paleomagnetism:
o how iron in rocks acquires a magnetic field in a direction
o polarity reversals
o how paleomagnetism studies led to the discovery of the sea -floor spreading
Sedimentary Rocks - Chapter 6
Detrital - formed from the solid products of physical and chemical weathering.
Classified by grain size: gravels (conglomerate), sand (sandstone), silt (siltstone), clay (shale, mudstone)
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Above categories subclassified by mineral composition
Chemical - formed from chemical sediments, from dissolved products of chemical weathering, or
remains of plants or animals (Biochemical)
 Mechanism: evaporation, precipitation
 Classified by mineral composition:
o calcite, either inorganic or fragments of shells or coral reef (limestone)
o dolomite (dolostone)
o gypsum (rock gypsum)
o halite (rock salt)
o silica, either inorganic or organic (chert)
o plant remains (coal)
Lithification – set of processes that turn unconsolidated sediment into sedimentary rock
 Compaction
 Cementation – iron oxide, silica, calcite
Environments of Deposition – determines the type of sediment, and therefore sedimentary rock
Rocks to identify: sandstone, limestone, shale, conglomerate
Chapter 18 Geologic Time
Relative Dating - Key Principles
 Law of Superposition
 Principle of Original Horizontality
 Principle of Cross-Cutting Relationships
 Inclusions
 Unconformities - angular unconformities,
 Correlation: Using relative dating techniques to date a sequence of
sedimentary strata and structures.
 Relative dating problem, e.g. #21 from Ch. 18
Absolute Dating with Radioactivity
 Radioactivity – an unstable element decays, by gaining or losing nuclear
particles, and becomes another, more stable element
 Half life
 Carbon-14 dating
 how it forms, what it decays into
 how we use it to measure absolute ages
 why it is not useful for inorganic materials
 why it is not as useful in dating material older than 50,000 years
 how we correct for variations in C-14 levels in the atmosphere
 Other materials used for Radioactive Dating, e.g. uranium, Potassium and
their use in dating older materials.
 Uranium and its use in establishing the age of the Earth.
Geologic Time Scale and its Eras
 Paleozoic, Mesozoic, Cenozoic Eras
 The time boundaries between the eras represent times of mass extinctions
and the evolution of new species
Time boundaries between the subcategories (e.g. periods and epochs) based on
less catastrophic changes in life forms.
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