Nevada Today Story Features NBMG Research Team

Finding FaultsHow the Burgeoning Walker Lane May Split the American West
By Mike Wolterbeek, Nevada Today, February 18, 2020

Excerpts: “California won’t fall into the ocean, but it could get nudged hundreds of miles offshore, making Nevada the new coastline of the continent, scientists at the Nevada Bureau of Mines and Geology at the University of Nevada, Reno hypothesize. They have combined decades of data and the latest technology to study the Walker Lane, an approximately 1000-kilometer-long (625 miles) corridor riddled with hundreds of earthquake faults.

Several researchers at the University are part of a group of scientists who are studying the massive system of relatively discontinuous faults that runs through western Nevada. It is known as the Walker Lane and in about 7-8 million years or so could become the new tectonic boundary between the North American and Pacific plates. The group at the University is relatively rare, as it includes expertise that analyzes fault zones at three different time scales from tens of millions of years (structural geology/tectonics) to the past approximately two million years (paleoseismology) to the present (geodesy). This combination of expertise is needed to understand the evolution of something potentially as grand as the Walker Lane.  In essence, the University team combines the most modern fieldwork techniques with the latest technologies such as satellites, LIDAR and computer simulations…”

“But it’s the combination of three science disciplines that illustrates the prominence of the Walker Lane – paleoseismology, geodesy and Faulds’ specialty of structural geology/tectonics. All three perspectives are crucial in analyzing something like the Walker Lane, because they provide three different timeframes with which to evaluate the evolution of the Walker Lane – from what’s happening now, to the past million years or so, and to the long-term (back-tracking tens of millions of years). We have all three disciplines in the College of Science at the University of Nevada, Reno…”

Read the complete version of this interesting story/presentation!

The NBMG research team described in this story includes Jim Faulds, Rich Koehler, Jayne Bormann, Bill Hammond, Corné Kreemer, Geoffrey Blewitt, Seth Dee, Chris Henry, and students Colin Chupik and Conni De Masi.

New Research Published by NBMG Faculty

Footwall rotation in a regional detachment fault system: Evidence for horizontal‐axis rotational flow in the Miocene Searchlight pluton, NV
By Andrew V. Zuza, Wenrong Cao, Nicholas H. Hinz, Joel W. DesOrmeau, Margaret L. Odlum, and Daniel F. Stockli
Tectonics, Volume 38, Issue 7, July 2019, pages 2506-2539
First published: 08 July 2019
https://doi.org/10.1029/2019TC005513
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019TC005513

Hydrothermal circulation cools continental crust under exhumation
By Wenrong Cao, Cin-Ty A. Lee, Jiaming Yang, and Andrew V. Zuza
Earth and Planetary Science Letters,Volume 515, 1 June 2019, Pages 248-259
https://www.sciencedirect.com/science/article/pii/S0012821X19301773
https://doi.org/10.1016/j.epsl.2019.03.029

Oxygen isotopic investigation of silicic magmatism in the Stillwater caldera complex, Nevada: Generation of large-volume, low-δ18O rhyolitic tuffs and assessment of their regional context in the Great Basin of the western United States
By Kathryn E. Watts; David A. John; Joseph P. Colgan; Christopher D. Henry; Ilya N. Bindeman; and John W. Valley
GSA Bulletin (2019) 131 (7-8): 1133-1156
Research Article, February 14, 2019
https://doi.org/10.1130/B35021.1
https://pubs.geoscienceworld.org/gsa/gsabulletin/article/131/7-8/1133/568805/Oxygen-isotopic-investigation-of-silicic-magmatism

Igneous rocks in the Fish Creek Mountains and environs, Battle Mountain area, north-central Nevada: A microcosm of Cenozoic igneous activity in the northern Great Basin, Basin and Range Province, USA
By Brian L. Cousens, Christopher D. Henry, Christopher Stevens, Susan Varve, David A. John, and Stacey Wetmore
Earth-Science Reviews, Volume 192, May 2019, Pages 403-444
Received 11 September 2018, Revised 6 March 2019, Accepted 14 March 2019, Available online 18 March 2019.
https://doi.org/10.1016/j.earscirev.2019.03.013
https://www.sciencedirect.com/science/article/pii/S0012825218305208

Latest News from the Nevada Geodetic Laboratory

[June 18, 2018] New paper published on the August 24, 2014 M6.0 South Napa Earthquake

“A new paper published by Nevada Geodetic Laboratory Graduate Student Meredith Kraner uses data from high‐precision continuous GPS stations to observe a 3 mm horizontal expansion of the Earth’s crust prior to and in the vicinity of the August 2014 M6.0 South Napa earthquake. The study is a collaboration with William Holt from Stony Brook University, and Adrian Borsa from Scripps Institution of Oceanography at UC San Diego. The analysis looks at eight years of continuous GPS data leading up to the earthquake and finds that this pattern of horizontal crustal extension repeats every summer. The effect releases pressure on faults in the West Napa fault system, making them more likely to slip during the summer months. We speculate that large seasonal variability in the amount of groundwater in the Sonoma and Napa Valley subbasins may contribute to the observed changes.

Read more in the paper, which has been published in the Journal of Geophysical Research, Solid Earth and is available online here:

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2017JB015420

Also see features from the AGU, AP news, KCBS radio, and Live Science.” (from NGL website)

NPGS Graduate Student Research Awards in Geosciences

NPGS logo

2015 Application Announcement
THE NEVADA PETROLEUM & GEOTHERMAL SOCIETY
Graduate Student Research Awards in Geosciences

Three to five grants up to $1000 each. Amounts and number of awards will depend on proposal quality, number of proposals, proposal budgets, and applicant need.  Awards will be available to support research beginning in the summer of 2015.  Applicants must be graduate students in good standing. Successful applicants will be expected to present their results to the Society upon degree completion.

Guidelines: Research topics should be:

  • related directly to geology of the Great Basin, and
  • of general interest to those interested in bedrock geology problems.

Students working on litho-stratigraphy, biostratigraphy, structure, geothermal systems, geophysical exploration, geochemistry of sedimentary rocks, and tectonic history are especially encouraged to apply.

To apply: Send or email (as PDF file) a 2page (maximum) research proposal (include results to date, bibliography, and budget), a short (one page) vita that includes academic progress so far, and a letter of recommendation from your academic advisor (sealed if mailed or emailed direct from advisor) to:

Dr. James Trexler
NPGS Scholarship Chairman
Department of Geological Sciences and Engineering
MS 172 University of Nevada, Reno
Reno, NV 89557
trexler@unr.edu

Application materials must be received or postmarked by March 13, 2015
More information? Contact: trexler@unr.edu

Student Awards at GSA in Nevada Today—Carlson, Di Fiori, and Edwards

Mackay/NBMG graduate students Chad Carlson, Russell Di Fiori, and Joel Edwards are featured in this article in Nevada Today for their outstanding clean sweep of student awards at GSA.

University Geology program excels at Geological Society of America meeting in Vancouver: Students took gold, silver and bronze medals in the Student Map Competition
By: Shelby Wilburn and Annie Conway (in Nevada Today, 2/2/2015)

University of Nevada, Reno Geology students exhibited their passion and skill on the international stage. The three participants secured a clean sweep in the Student Geologic Map Competition at the 126th annual meeting of the Geological Society of America in Vancouver, BC with first, second and third place finishes.

“The annual GSA student geologic map competition is an open call for geoscientist students across the country to submit their independent geologic mapping efforts of bedrock and surficial features into the competition to be judged and compared with peer efforts,” Joel Edwards, the third place finalist in the October 2014 competition, said. “Mapping efforts must be the significant component of the thesis and students must be the principal author to qualify.”

The talented group consisted of current and recent graduate students. Gold medalist, Chad Carlson is currently a doctoral student under advisor James Faulds, the state geologist, director of the Nevada Bureau of Mines and Geology and professor at the University. Carlson received top honors for his Geologic Map of the Terrill Mountains in western Nevada. Silver medalist, Russell Di Fiori graduated in May 2014 with a master’s degree in Geology. Di Fiori earned second place with his Geologic Map of the Eureka Mining District in eastern Nevada. Sean Long, assistant professor with the Nevada Bureau of Mines and Geology, served as Di Fiori’s advisor. Edwards sealed the sweep with third place, for his Geologic Map of Neal Hot Springs in eastern Oregon. He graduated with a master’s degree from the program in 2013. Faulds also served as Edwards’ advisor.

“It was an honor to be recognized along with my fellow Nevada Bureau of Mines and Geology and University of Nevada, Reno geology graduate students,” Di Fiori said. “Both Chad and Joel are fantastic field geologists, and I am glad to be counted among them. It was definitely a pleasant surprise for the ‘clean sweep’. It also feels good to have our hard work be appreciated by our peers as well as seasoned professionals.”

The extensive process required months of dedication and consistency. All three students spent significant amounts of time generating detailed maps of complex geological regions. The group was supported throughout development by the Cartographic/GIS staff at the Nevada Bureau of Mines and Geology. Individuals assisted with the layouts and provided technical assistance on the maps. Nicholas Hinz, geologic mapping specialist at the Nevada Bureau of Mines and Geology, also contributed toward many facets of the maps.

“I learned a ton from the whole mapping process,” Edwards said. “It’s not easy. It’s physically and mentally demanding, even exhausting at times. But it’s a really neat experience to be able to walk over a terrain enough times to finally figure out the story beneath your feet, the Earth’s story.”

The Geological Society of America Annual Meeting is designed to share scientific results with the broader geoscience community. GSA strives to foster innovative research that transforms the understanding of geologic processes that have formed the world. They aim to advance understanding of global resources, geohazards, and the environment. GSA’s geoscience research profoundly impacts education, publications and public policy.

See article with photos here:
http://www.unr.edu/nevada-today/news/2015/student-map-competition

Hammond and Blewitt Paper in Nature

hammond_CA_aqueduct_GreatValley_f
Water in Southern California’s Great Valley flows along the California Aqueduct. Credit: Bill Hammond

Bill Hammond and Geoff Blewitt (both of Nevada Bureau of Mines and Geology/Nevada Geodetic Laboratory and Nevada Seismological Laboratory in the College of Science at UNR) are co-authors on this paper released online May 14, 2014 in the journal Nature.

Uplift and seismicity driven by groundwater depletion in central California
 By Colin B. Amos, Pascal Audet, William C. Hammond, Roland Bürgmann, Ingrid A. Johanson, and Geoffrey Blewitt

Nature (2014) doi: 10.1038/nature13275
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13275.html?WT.ec_id=NATURE-20140515

Abstract: “Groundwater use in California’s San Joaquin Valley exceeds replenishment of the aquifer, leading to substantial diminution of this resource [references 1-4] and rapid subsidence of the valley floor [reference 5]. The volume of groundwater lost over the past century and a half also represents a substantial reduction in mass and a large-scale unburdening of the lithosphere, with significant but unexplored potential impacts on crustal deformation and seismicity. Here we use vertical global positioning system measurements to show that a broad zone of rock uplift of up to 1–3 mm per year surrounds the southern San Joaquin Valley. The observed uplift matches well with predicted flexure from a simple elastic model of current rates of water-storage loss, most of which is caused by groundwater depletion [reference 3]. The height of the adjacent central Coast Ranges and the Sierra Nevada is strongly seasonal and peaks during the dry late summer and autumn, out of phase with uplift of the valley floor during wetter months. Our results suggest that long-term and late-summer flexural uplift of the Coast Ranges reduce the effective normal stress resolved on the San Andreas Fault. This process brings the fault closer to failure, thereby providing a viable mechanism for observed seasonality in microseismicity at Parkfield [reference 6] and potentially affecting long-term seismicity rates for fault systems adjacent to the valley. We also infer that the observed contemporary uplift of the southern Sierra Nevada previously attributed to tectonic or mantle-derived forces [references 7-10] is partly a consequence of human-caused groundwater depletion.”

Press release from NSF:
http://nsf.gov/news/news_summ.jsp?cntn_id=131393&org=NSF&from=news

Links to other stories about this research:
http://newscenter.berkeley.edu/2014/05/14/central-valley-groundwater-depletion-raises-sierra-and-may-trigger-small-earthquakes/

Read about the Nevada Geodetic Laboratory:
http://geodesy.unr.edu/