1.The rocks and sediments that fill in the Gulf of Mexico, especially for Miss.-Louisiana-Texas, can be broken into three main types of rock units, based on the dominant rock type (relates to how the dominate rock type formed). a) What are these three rock types (in order from oldest to youngest) and provide a brief description of how they formed. b)The first (oldest) unit is important in the petroleum industry due to the structures it forms in the subsurface. Explain how these structures formed and why they influence hydrocarbon exploration. (Hint: it’s not just one feature that results from this unit—do other structures or geologic features form as a result that may influence hydrocarbon accumulation?).
Name: _______________________
GEOL3200
Spring 2020
Final Exam (optional)
Submit your answers to the Moodle folder ‘Final Exam’ by 8am Wednesday 6th.
There are 9 questions choose 6 to answer.
Answer in your own words. I will be checking for plagiarism.
Use the resources that are available (powerpoint, classnotes, homework, e-textbook…)
1. The rocks and sediments that fill in the Gulf of Mexico, especially for Miss.-LouisianaTexas, can be broken into three main types of rock units, based on the dominant rock type
(relates to how the dominate rock type formed). a) What are these three rock types (in
order from oldest to youngest) and provide a brief description of how they formed. b)
The first (oldest) unit is important in the petroleum industry due to the structures it forms
in the subsurface. Explain how these structures formed and why they influence
hydrocarbon exploration. (Hint: it’s not just one feature that results from this unit—do
other structures or geologic features form as a result that may influence hydrocarbon
accumulation?).
2. Describe the difference between relative and absolute dating of geologic units. Provide
techniques for each (don’t just name them, you need to describe them or you’ll only get
partial credit). Some questions to help: what are some fundamental concepts used in
relative dating?, What is the common technique used for absolute dating?, What are some
other techniques that can be used for absolute dating?
3. Describe the requirements for organic matter to be preserved so that if buried and
subjected to increased temperatures for a given amount of time it turns into hydrocarbon?
Some helpful questions: what are the conditions for organic matter to be preserved?, what
type of organic matter produces gas/oil vs. coal?, does grain size influence the
preservation in organic matter and why?, high or low energy deposition environments?…
4. What are the two main types of hydrocarbon traps? Provide two examples for each. What
is important about relative age of hydrocarbon/migration and trap formation between the
two main types of hydrocarbon traps?
5. Describe and/or draw a sketch of the three different types of unconformities. What
geologic processes would each experience?
6. What are the advantages and disadvantages of seismic surveying compared with
geological cross-sections, or a well log of a borehole? Would subsurface interpretations,
as well as oil exploration, be more confident with more than one technique, why? (think
about, scale, what information is provided and not provided just from seismic surveys,
what issues comes with interpreting)
7. Briefly explain how CO2 in the atmosphere varies on a seasonal basis, and over the past
50 years. What is the most likely reason for this?
8. How does the trend of CO2 concentration in the past 50-60 years compare to the past
800,000 years of Earth’s history? Where do we get current and past information on
atmospheric composition, thus inferences to how climate has changed over Earth’s
history?
9. What correlation techniques are using in the following figure to link the 9 stratigraphic
sections? Which way (to left or right) was the depositional center? What kind of
hydrocarbon traps would you expect here? From identifying the sequence boundaries;
how many cycles of lake-level rise and fall are observed? (A sequence is one
transgressive and one regressive event, where the sequence boundary is defined by an
erosional surface indicating the regressive event extent. A maximum flooding surface is
the farthest extent of the facies during a transgression (in other words the point between
a transgression switching to regression).