PG Lecture Exam 2 Review
Sediments
What are sediments? What is the most common sedimentary rock on the surface? Chemical vs
physical (mechanical) weathering. Types of each. What are weathering feedbacks? What are soils, what are
soil horizons, what horizons comprise the topsoil? How is soil formed, specific factors related its
formation. Why must soils be managed and conserved? What are the four classes of sedimentary rocks?
What are these processes as they related to sedimentary rocks: weathering, erosion, transportation,
deposition, lithification. What means transport sediments, most effective? How does grain size relate to
transport? What do such characteristics as angularity and sorting tell us about the history of a sediment?
How are clastic sedimentary rocks classified? What is a transgression, a regression, how is this manifested
in the distribution of sediments? What is the carbonate factory, what environmental conditions do
carbonates require to flourish? What are sedimentary structures and how are they useful to scientists? What
are the major depositional environments and what are the common types of sediments found in those
environments? What is the problem with dolostone?? = poor understanding of how it forms, we do know it
is a high Mg form of carbonate, and the process is thought to be the result of several potential causes, one
of which is chemical alteration and replacement of Ca atoms within the crystal lattice of a limestone.
Metamorphism
What is it, how is it manifested, what is the process, protoliths-what are, what protoliths produce
common metamorphic rocks. What induces metamorphism? what changes occur during metamorphism?
How is metamorphism related to rock cycle? What are differences between diagenesis, and metamorphism?
What are metamorphic facies? Is weathering the same as metamorphism? What are the temperature and
pressure conditions associated with high grade vs low grade metamorphic rocks? What are prograde vs
retrograde trajectories in pressure-temperature space? What are metamorphic aureoles, type of
metamorphism they are associated with? Can metamorphic facies vary across a region that has been
subjected to orogenesis? Does metamorphism every involve melting? What is foliation and how does it
occur during a metamorphic event?
Volcanism
What types of products are produced from volcanic eruptions? What is contained in the eruption
columns commonly seen above central vents of strato volcanoes? What are the broad chemical differences
between rhyolites (felsic rocks), andesites (intermediate rocks), basalts (mafic rocks) with respect to silica,
Fe and Mg content; volatile content; viscosity; temperature, flow characteristics, eruptive styles? What are
pillow laves, how/where do they form? What are pyroclastic materials, what are the categories for naming
the different classes based on? What is ash vs lapilli vs blocks/bombs? What are lahars, what are they
made of, where are the found, what might start a lahar, what is a lahar made of? What are the most
common volatile phases present in melts? What effect do volatiles have on melting temperature, degree of
explosivity of an eruption, viscosity of a melt, ability of a melt to flow? What are the general flow
characteristics for each of the major categories of melts we've discussed? What are calderas, how do they
form, what is the style of eruption associated with caldera formation? What are mantle plumes, what are
some of the alternative models to explain the existence of intraplate volcanism? Are mantle plumes
universally accepted? What is a hot spot? What are rifts, what style/type of volcanism is most often
associated with continental rifts? Why is Iceland a unique example of volcanism on Earth, what makes it
unique?
Earthquakes
What are the 3 types of faults we discussed? What are the stress orientations in each of these?
What is the hanging wall vs the foot wall? Be able to draw a cross-sectional sketch of each fault type
labeling each block and the relative motions. What are faults, joints, epicenter, hypocenter or focus. How is
the epicenter of an earthquake determined. What are the different types of seismic waves-the major classes
and the subdivisions within each class, where does each wave type propagate, what are the relative speeds
of the 4 types of seismic waves? What opposes slip along fault planes? What are foreshocks, aftershocks,
how do the relate to the main earthquake? What type of plate boundary do the largest most damaging
earthquakes form? Type of faulting at each type of plate boundary, orientation of stresses. Can earthquakes
be reliably predicted on short/long term basis based on science? What are animal precursors prior to
seismic or volcanic events, how does science view these? What are tsunamis, how are they generated.