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COVER PAGE: RMS-GSA UNDERGRADUATE RESEARCH GRANT
Please fill out this form completely.
Proposals lacking a complete form will not be considered.
1. Submitted by Name: Amy Asanuma
Department & Institution: University of Idaho, Department of Geology
Phone: (707) 535-6641
Email: asan3900@vandals.uidaho.edu
2. Project Title: From Shore to Sea: Is the Borah Peak Fault Scarp Representative of an Ancient
Continental Margin?
3. Faculty Advisor Name, Email, and Tel. No.: Peter Isaacson, isaacson@uidaho.edu, (208) 885-2930
4. Amount Requested: $500.00
5. Project Dates: September 2013 – November 2013
6. Project Description: Present a brief (maximum of 2 pages, including figures) description of the
proposed project, including research question(s) to be addressed, methods, analyses, and schedule for
proposed activities. Applicants must use 12-point font (Arial, Times New Roman) with 1-inch margins at
the top and bottom, and pages numbered consecutively. A list of references should be provided and will
not count toward the 2-page limit. The budget and budget justification do not count toward the 2- page
limit.
7. Budget Information. Provide an itemized budget. The budget and budget justification do not count
toward the 2-page limit for the project description.
8.Budget Justification. Provide a detailed budget justification. Include rationale for proposed costs. The
budget and budget justification do not count toward the 2-page limit for the project description.
9. Support letter: A letter of support from your faculty advisor must be submitted. The letter should be
sent to Erin Campbell-Stone, RMS-GSA Vice-Chair, (erincs@uwyo.edu)
10. Deadline: Complete packet must be received by March 20, 2013, 5:00 P.M. Mountain time.
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Project Description
Idaho’s Borah Peak earthquake of 1983 was the largest and most damaging earthquake
ever recorded in the state’s history. As a result of the 7.3 magnitude tremor, several
new “steps” on the ground surface, known as fault scarps, display the location of the
fault. These “steps” lie directly over the fault and show vertical movement of one side of
the fault in respect to the other. In this instance, the scarp exists because Borah Peak
rose over 2.1 m from ground elevation as a result from the earthquake.
The region is part of the Lost River Range as well as a member of the Intermountain
Seismic Belt. The range resides in southern Idaho beside the Lemhi Range. Silurian
marine sediment in central and southeastern Idaho suggests the presence of a shallow
marine continental shelf. Paleozoic changes in the earth’s crust suggest evidence of a
continental margin that coincides with the Borah Peak fault scarp. The question I want
to answer is: Is the Borah Peak fault scarp representative of an ancient continental
margin boundary? I hypothesize there is evidence to confirm the relationship.
Fig. 1 A sample taken from the region
that sums up the various depositional
environments. The coral and shell
fragments embedded in sand sized
particles are indicative of a shallow
marine environment. The thinly
layered muds and clays, in contrast,
suggest a deep marine environment.
Methods
Over the course of four days, I will travel down to the Challis, ID area. I plan to conduct
a transect study beginning at the Lemhi Range, northeast of the Lost River Range,
observing shallow water sediments. The middle section of the transect will take place at
the Roberts Mountains formation in Nevada, which is possibly right off the continental
margin. Moving west towards Ketchum, where sediment movement was influenced by
gravity rather than the continental margin, I will study the deep water graptolitic facies.
Graptolites are used index fossils to date samples, because they are found in early
Paleozoic deep marine rocks. They are also normally deposited within thin shale and
mud layers. After completing and correlating numerous stratigraphic columns of all three
areas, I will create a cross-sectional view of the area to visually represent the potential
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relationship of the proposed continental break and the Borah Peak fault scarp. In
addition, I will prepare 25 thin sections for each area from the collected samples.
Analysis
The presence of photosynthetic algae along with in situ fossils and corals in thin section
suggest a low energy depositional environment, such as shallow marine. Clays and
mud in thin section are indicative of a deep marine basin depositional environment.
Upon observing slides taken from areas the Lemhi and Lost River ranges, I will look for
evidence of sand from shore. There will most likely be characteristics from both shallow
and deep marine environments. Some slides may present fossils embedded in shore
sand while others may show clays and muds with occasional graptolite fossils. If I can
confirm the characteristics of both environments, then the Roberts Mountains formation
serves as a transitional zone between shallow and deep marine environments.
Lastly, I will characterize the lithology to seek evidence from material that could have
come from near source or far source. If it stems from a far source it denotes the
existence of open ocean, further confirming the ancient continental margin.
I will be able to determine if there is relationship between the Borah Peak fault scarp
and an ancient continental margin with a cross-sectional view and recordings from 25
slides from each area.
Schedule for Proposed Activities
September 5 2013: Meet with assistants; acknowledge protocol and objectives
September 6-9 2013: Travel to central Idaho by car to collect samples from the three
regions
September 10 2013: Return to Moscow
September 11 – November 2013: Analyze samples; begin drawing conclusions
March 1 2014: Submit final report
May 2014: Present at GSA Rocky Mountain Section
Budget Justification
A weekend during the fall, I plan to travel to Challis, ID and stay at the Challis Hot
Springs Campground. The grounds charge 21 dollars a night, which equates to 64
dollars for the trip. The distance between Moscow and Challis is approximately 450
miles according to Google maps and the present vehicle reimbursement rate is 51 cents
a mile. Meals will be cereal and sandwich material. Thin sections cost approximately 5
dollars to make, and my study requires 75. I also will need sample bags, maps and
formic acid for field work. What will not be funded will come out of pocket.
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References
Crone, Anthony J., and Michael N. Machette. “Surface faulting accompanying the Borah
Peak earthquake, central Idaho.” Geology v. 12 (1984): 664-667. Print.
King, John J., Timothy E. Doyle, and Suzette M. Jackson. “Seismicity of the Eastern
Snake River Plain Region, Idaho, Prior to the Borah Peak, Idaho, Earthquake
October 1972-October 1983.” Bulletin of the Seismological Society of America
77.3 (1987): 809-818. Print.
Scott, William E., Kenneth L. Pierce, and M. H. Hait, Jr. “Quaternary Tectonic Setting of
the 1983 Borah Peak Earthquake, Central Idaho.” Bulletin of the Seismological
Society of America 75.4 (1985): 1053-1066. Print.
Susong, David D., Susanne U. Janecke, and Ronald L. Bruhn. “Structure of a Fault
Segment Boundary in the Lost River Fault Zone, Idaho, and Possible Effect on
the 1983 Borah Peak Earthquake Rupture.” Bulletin of the Seismological Society
of America 80.1 (1990): 57-68. Print.
Treadway, Jeffrey A. “Shallow Seismic Study of a Fault Scarp Near Borah Peak, Idaho.”
Print.