WINTER 2010 GES 283:
USING THERMOCHRONOLOGY TO
CONSTRAIN CRUSTAL DEFORMATION;
FUNERAL MOUNTAINS, DEATH VALLEY
INSTRUCTORS:
Emily Peterman and Marty Grove will be leading this course, with contributions from
Elizabeth Miller, Gail Mahood, Chris Mattinson (Central Washington University), Jeremy
Hourigan (UC Santa Cruz), Thomas Hoisch (Northern Arizona University) and Michael
Wells (Univ. of Nevada, Las Vegas).
COURSE DESCRIPTION:
This seminar and field-based course will teach you how to assess and measure the timing
and rates of crustal deformation. We will focus on constraining the exhumation history of
the Monarch Canyon Springs fault in the Funeral Mountains of Death Valley through a
combination of field and seminar based meetings. The course will meet once a week for 2
hours during Winter Quarter 2011 and travel to Death Valley over Spring Break 2011 for a
week-long field trip. You will gain real-world experience with (1) presenting scientific
literature, (2) identifying geologic problems, (3) designing experiments for specific
hypothesis testing, (4) conducting field work and sample collection, (5) processing samples,
(6) data collection, (7) data interpretation and (8) writing a geologic report. The course is
open to upper division undergraduates and graduate students.
The seminar portion of the course will discuss metamorphic core complexes and the
exhumation of large-scale terranes, with emphasis on the evolution of Western North
America. In addition to learning about tectonic processes, we will also devote a few class
meetings to discussing how we measure the timing and rates of crustal evolution and
deformation (e.g. thermochronology). In the field segment of the course, we will visit awe-
inspiring geologic locations, including Aguereberry Point, Mosaic Canyon, the Badlands
and Mormon Point. We will then spend a few days conducting bedrock mapping and
sample collection in Monarch Canyon (Funeral Mountains).
A third component of this course will be taught during Spring Quarter 2011. In this course,
you will work in groups to process samples for mineral separations and thin section
petrography. We will use the samples collected over Spring Break to select grains for
muscovite and K-feldspar 40Ar/39Ar thermochronology and coupled (U-Th)/(Pb-He)
monazite and zircon chronology. We will also conduct detailed analysis of the phase
relations visible in thin section. As a final project, we will submit a co-authored paper for
publication.
COURSE OBJECTIVES:
In this course, your assignments will help you develop communication, critical thinking and
analytical skills. You will develop these skills through giving an oral presentation(s) of a
paper, writing a 1-page summary of the paper you present, hypothesizing what different
thermochronology results would mean in terms of the geologic history of the Death Valley
region and identifying which thermochronometers will likely yield the most relevant
information. The field component will build heavily upon the knowledge you gain during
the seminar and will develop your skills as a field geologist. While these objectives are
targeted at preparing you as a geologist, the skills you learn will be relevant in any career
path you choose.
SEMINAR
Each seminar will begin with a one-hour introduction to the topic of the day by the speaker
(see calendar). There will be ~2 papers to read for this section each week. The second hour
will be reserved for a student presentation of a paper. Each student will present a paper and
will be evaluated on the quality, clarity and effectiveness of your presentation. In addition to
an oral presentation, you will prepare a 1 page summary of the paper that highlights what
you perceive as the most important components or contributions from the paper. You will
also be evaluated by your level of participation in the seminar when you are the audience—
specifically, we will be looking to see what questions you ask during the seminar and how
you contribute to meaningful discussion. Additionally, you will:
• Summarize the geologic history of the Death Valley area
• Compare and contrast the leading hypotheses for the timing and magnitude of
extension in the Monarch Canyon area
• Evaluate and compare thermochronologic techniques and assess which will yield the
most useful information for our scientific objectives
FIELD
During the field trip, we will be exploring several locations in Death Valley National Park
and conducting field research. We will provide you with more details prior to and during
the trip, but some of the highlights of assignments and activities include:
• Identify and describe the phases of metamorphism and deformation in Mosaic
Canyon
• Create a geologic map of the field area, Monarch Canyon, including structural
measurements and lithologic descriptions
• Collect samples for thermochronology, Monarch Canyon
• Write a summary of what we discover for the general public. This will be put on
display at the Park Station.
SYNTHESIS
For students who are interested, a follow-up course will be taught in Spring Quarter 2011.
In this complementary course, we will write up the findings from field aspect of the course
and publish a paper.
• Generate temperature-time histories for the Monarch Canyon area using (U-Th)/Pb
geochronology from monazite and zircon, the 40Ar/39Ar multi-diffusion domain
approach applied to K-feldspar, and (U-Th)/He and fission track thermochronology
data from monazite, zircon and apatite.
• Compare the new thermochronology data with previous work from the region
• Interpret the significance of these integrated temperature-time histories for the
tectonic history of Monarch Canyon
• Describe the geologic history of the deep crustal rocks of the Death Valley area in a
scientific report that we co-author using the data collected in this study and data
presented in the literature.
