ESC 102 Summer 2009
Review Topics for Test I
Test will include multiple choice, some short answers, and two brief essays.
There will be a choice of essays. The questions will be taken directly from
the Study Guide Objectives. In all cases, the question will require an
explanation, not just a list of facts.
Scantrons are recommended for Part 1, but are not required.
Review using your class notes, instructor’s notes, review terms, figures and
questions from the text, and practice questions on Web Page.
Topics MAY include the following:
Chapter 1 See “Terms”, Review questions 1, pg. 14: 1-12. Note Figures: 1.2, 1.6, 1.7,
1.8, Table 1.2, Fig. 1.9,
Age of universe and evidence for this
Big bang model
Age of earth and evidence for this
Solar nebular hypothesis (called theory in the text)
Layers of the earth chemical (3) physical (5)
Planets: terrestrial and jovian
Hypothesis, theory, law, scientific method
Spheres of the earth
Principle of uniformitarianism vs catastrophism
Basis of creation of geologic time scale
Chapter 2 Periodic Table Review Sheet
See “Terms,” Review questions page 34: 1,2,4,5,12, 15, 16; Note Figures: 2.3, 2.4, 2.6,
2.7, 2.16
Elements and atoms:
Parts of atom, nucleus, protons, neutrons, electrons
atomic number, atomic mass, isotopes, valence electrons
Bonding: types: ionic (halite or salt), covalent (diamond), metallic (copper, gold)
Mineral: definition;
properties such as hardness, luster, cleavage, fracture, streak
How to identify (no specific minerals need to be memorized)
Silicon and oxygen most abundant by weight in crust: silicates most abundant minerals
ferromagnesian (dark color, more dense, rich in iron and magnesium) and nonferromagnesian minerals (light color, less dense, lacking iron and magnesium)
Rocks: 3 types, how each is formed, where formed on Earth?
Igneous, metamorphic, sedimentary
Igneous: Formed by melting within the mantle (where? divergent boundaries, convergent
boundaries, hot spots) Examples: basalt, granite
Metamorphic: formed from “parent” rock that undergoes heat, pressure, or contact with
hydrothermal fluid (where? near igneous intrusions, at convergent boundaries, within
deeply buried sedimentary rocks). Examples: slate, marble
may exhibit foliation (alignment of minerals or apparent “layers” of minerals) due to
stress on the parent rock
Sedimentary: Formed from existing rock as solid rocks weather mechanically. Pieces
are buried, compacted and cemented to form a new rock.
Also formed from chemical weathering where minerals are dissolved in fluid then
precipitated (solidified) again when the fluid evaporates or becomes saturated. (example:
halite = rock salt)
Sedimentary rocks form in all environments on Earth as the solid earth breaks down,
waters evaporate, or minerals precipitate from water.
Continental crust is typically granite composition Density 2.3 g/cm3
Oceanic crust is typically basalt composition Density 3.0 g/cm3
Rock cycle: illustrates that the solid material on earth is built up and broken down by
processes both within Earth’s interior and on the surface. This material may be
“recycled” among the rock types.
Chapter 3 pages 35-54
See “Terms”, Review questions: 1, 3-7, 10-13 (text); Study Guide,
Plate Boundary Chart & Map
Sketch and label all the plate boundary types (total 7)
Continental drift hypotheses – Wegener 1912
Evidence: fit of the continents, fossils glossopteris and mesosaurus, glacial evidence (till
and striations), rock type and age (Appalachian, Atlas, Caledonian mountain ranges
similar), paleomagnetism recorded in continental rocks points to the poles and documents
the changing strength of magnetic field in the past; polar reversals, apparent polar
wandering
Magnetite minerals: align with poles when cooled below the Curie point; alignment with
magnetic pole and dips with angle showing latitude where the mineral cooled.
Seafloor spreading – Hess 1960s: magnetic studies of the seafloor
Magnetic reversal patterns discovered as “stripes” in ocean crust parallel to mid ocean
ridges, also discovered while exploring ocean bottom.
Plates contain continents and ocean crust.
Discovery of the mid-ocean ridge system
Evidence for Seafloor Spreading: magnetic anomalies in strength of magnetic field in
patterns; polar reversals recorded on both sides of ridge; radiometric dating of oldest
crust <180my old and away from the ridge, closer to the subduction zone and trench.
Plate tectonics theory:
Plates move over asthenosphere (weak layer)
Mechanism: heat transfer – convection currents in mantle (upper mantle model, or whole
mantle model not yet determined)
Unifying theory: plate tectonics explains all of the above evidence by the continents
moving over earth and ocean basins opening and closing over long period of time.
Explains location and occurrence of earthquakes, and volcanoes.
Boundary types:
Divergent – 2 types
mid ocean ridge and continental rift valley (location of examples!)
Convergent – 3 types
ocean-ocean: when plates collide, the older, colder slightly more dense crust usually
subducts under the younger crust. See diagram in book Fig. 3.18.
Volcanic Island Arc results from ocean-ocean (location of examples!)
Ocean – continent: when plates collide, the dense, thin ocean plate subducts beneath the
less dense thicker continental crust.
Continental Volcanic Arc (example?)
Features of subduction zones: subducting crust, deep ocean trench, overriding crust, area
of deformation crust and ocean floor sediments (become metamorphic rocks), partial
melting along the ocean crust (slab) at about 100km depth, line of volcanoes on
overriding plate, back arc basin behind the volcanoes and away from the crust.
Continent – continent: when ocean basin closes, subduction stops. Continents that
converge are characterized by metamorphism and uplift of rocks at the boundary. Very
thick continental crust results. (no volcanism) (example?)
Transform boundary: when one plate slides past another plate, such as ocean/continent
at San Andreas Fault in California. Also in ocean crust at mid ocean ridge, cracks in the
crust that are perpendicular to the ridge are where ocean crust is moving away from ridge
but sliding past ocean crust that is not moving above or below the cracks.
Hot spots – not associated with any tectonic boundary. Stationary mantle plume brings
magma to the surface and forms volcanoes. A chain of volcanoes shows how the plate
moved over the hot spot (example?)