Study Outline for Geo 103-03 - Exam 3 - Fall 2006
You are responsible for all of the assigned readings in your text; the
material in the lecture notes (Lecture Sets 13, 15-18, 20, 21); the material from the Earth
Revealed Videos; and the assigned material on the GEODE CDROM and PH Web Site.
Below, you will find a list of material that was emphasized
in the lecture notes. This is not meant to be an all inclusive
list of material that will be on the exam. Study hard and good luck!
I. Fundamental Geological Principles and Earth's Interior
- Fundamental geologic principles
- uniformatarianism
- superposition
- geologic time; dating
(relative & absolute dating)
- fossil succession
- Earth's structure
- endogenic
& exogenic processes
- isostasy
- earth's internal
structure
- discontinuities (Moho & Gutenberg)
- Geologic Cycle
- Learning about Earth’s
Internal Structure: seismology - seismic waves
II. Plate Tectonics
- Continental drift
- Alfred Wegner
- Evolution of Pangaea
- evidence for
continental drift:
- fossils, rock
structures & type, fit of continents, paleoclimates,
paleomagnetism, magnetic reversals and
sea-floor spreading
- plate
tectonics - what is it?
- sea-floor spreading, subduction zones
- Earth's lithospheric
plates
- plate boundaries: convergent
(types), divergent, lateral (transform faults and relationship to
mid-ocean ridges)
- hot spots & Hawaiian Islands
III. Matter and Nature of Minerals and Mineral Groups
- Rocks vs. Minerals -
what makes a rock a rock, and a mineral a mineral?
- Mineral Composition
- atomic structure
- bond types - ionic (e.g.,
NaCl), covalent, and metallic
- isotopes
- Mineral Structure
- Physical Properties of
Minerals - crystal form, luster, color, streak, hardness, clevage, fracture, specific gravity
- Mineral Groups
- 8 common elements in
Earth's crust that comprise the "rock-forming " minerals
- silicate
mineral group - the most common mineral group
- carbonate mineral
group - 2nd most common mineral group
- Silicate Structures -
silicon-oxygen tetrahedron (SiO 4)4-
- single chain structure,
double chain structure, sheet structure
- most common ions in in rock-forming minerals
- Common Silicate Minerals
- Ferromagnsian
(Iron & Magnesium) Silicates - are dark in color and have a high
specific gravity - olivine, pyroxenes, amphiboles, biotite
(mica)
- Light Silicates -
"lower" specifc gravity than dark
silicates, light in color - muscovite (mica), feldspars
(the most common mineral group) [K feldspar (pink in color sometimes)
& plagioclase fleldspar (has striations)]
- Nonsilicate
Minerals
- carbonates -
basic structure is the carbonate ion (CO3 )2-
- calcite (CaCO3)
- dolomite (CaMg(CO3)2
- halides
- sulfates
IV. Igneous Rocks
- The Rock Cycle
- Magma vs. Lava
- Intrusive Igneous Rocks and
Intrusive Structures (e.g., plutons, laccoliths,
batholiths, dikes, sills; and tabular, massive, discordant and concordant
structures)
- Mama Crystallization
- Igneous Rock Composition
- Igneous Rock Textures
- aphanitic, phaneritic,
porphyritic, glass
- Classification of Igneous
Rocks & Igneous Rock Types
- Granitic,
Andesitic, Basaltic, Ultramafic,
Pyroclastic
- granite,rhyolite,
diorite, andesite, gabbro,
basalt, peridotite - know which are
intrusive and which are extrusive; also felsic
vs. mafic
- obsidian, pumice
- pyroclastic
rocks
V. Sedimentary Rocks
- weathering and erosion
produce material, which is deposited as "sediment",
and is then lithified (via compaction
and cementation) to form sedimentary rocks
- sedimentary rocks account for
5% (by volume) of Earth's outer 10 miles; and 75% of all rock outcrops -
they thus comprise a relatively thin and discontinuous layer in the
uppermost portion of the crust
- Detrital
Sedimentary Rocks - formed from material derived from both physical and
chemical weathering - originates and is transported in solid form
- particle size, shape,
texture, and composition provides information about the deposition
environment and the transport mechanism (e.g., wind, water, ice)
- sorting
- shale (mudstone &
siltstone) - accounts for over 1/2 of all sedimentary rocks - shales, because of their small pore space act as a
barrier to the movement of groundwater, petroleum, and natural gas
- sandstone
- 2nd most abundant sedimentary rock (~20%)
- conglomerate & breccia
- classification
- Chemical Sedimentary Rocks
- derive from material carried in solution
- precipitation of
material occurs via inorganic processes (evaporation &
chemical activity), & organic (biochemical) processes
(e.g., marine animals and plants extract dissolved calcite or silica to
build their shells or other hard parts)
- limestone - represents
about 10% of all sedimentary rocks - it is composed of calcite (CaCO3)
- both inorganic and
organic limestones exist
- coquina
- chalk
- dolostone
- comprised of dolomite
- chert
- comprise of silica
- evaporties
- e.g., halite (NaCl) - salt flats
- coal - comprised of organic
matter (dead plants) - forms in an oxygen-poor swamp environment -
peat>lignite>bituminous coal>anthracite
- Sedimentary Environments
- Sedimentary Structures
- strata (beds), bedding
planes, graded beds, cross bedding
- Lithification
= compaction & cementation
- cements: silica,
calcite, iron oxide
VI. Metamorphic Rocks
- Locations of
Metamorphic Rocks on the Earth's Surface
- Regional Metamorphism,
Contact Metamorphism
- Metamorphic Agents
- Heat
- (1) baking from
nearby magma & (2) heating due to burial at depth - associated with
convergent plate boundaries (subduction zones)
- Pressure
- confining
pressure - asssociated with depositional
environments - rocks deform by decreasing in volume
- directed
pressures - rock is shortened - associated with mountain building
- Chemically Active
Fluids
- water containing
ions in solution enhance the metamorphic process - the water acts as a
catalyst by aiding ion migration
- minerals sometimes recrystallize to form more stable structures
- or, ion exchange
results in the formation of completely new minerals
- Textural Changes
- the degree of
metamorphism is reflected in the mineralogy (composition) and
texture of metamorphic rocks
- Foliation -
results when the minerals and structrural
features of a rock are brought into alignment - the rock takes on a banded
or layered appearance
- the orientation is
perpendicular to the direction of the compressional
force
- there are many types
- platy clevage, schistosity
- Nonfoliated
Texture - metamorphic rocks composed of only one mineral which
form equidimensional crystals are not visibly
foliated
- Common Metamorphic Rocks
- Slate, Phyllite, Schist, Gneiss (all are foliated) Marble,
Quartzite (are nonfoliated)