A message from Sage Gandolfo, President of the Mackay Rockhounds Club: the Mackay Rockhounds Club Dead Day Mineral Sale is this Wednesday, May 9th from 3-6 PM in the Keck Museum.
Preliminary Geologic Map of the Lower Pahranagat Lake NW Quadrangle, Lincoln County, Nevada
by Thomas Price, Michael Evans, Mahmud M. Muhammad, Max Hinson, Alexis McIntyre, Alexander Peck, Philip Hahn, and Wanda J. Taylor
Series: Open-File Report 2017-03
Format: plate: 34.5 x 27.5 inches, color
View/Download/Purchase: http://pubs.nbmg.unr.edu/Prelim-Lower-Pahranagat-Lake-NW-p/of2017-03.htmThe Lower Pahranagat Lake NW quadrangle, Lincoln County, Nevada, includes Paleozoic strata, a Cretaceous-Tertiary sedimentary interval, Cenozoic units, and structures of at least two different deformations.
The exposed Paleozoic formations range from Ordovician Pogonip Group to Devonian Simonson Dolomite. These rocks are mostly carbonate, but some siltstone and sandstone, including the Eureka Quartzite, are interlayered. The Cenozoic units are subdivided into an Oligocene to Miocene section and a Pliocene to Quaternary section. The Oligocene-Miocene section contains mostly ash-flow tuffs that range from the 27.57 Ma Monotony Tuff to the ~15 Ma Kane Springs Wash tuff with minor siliciclastic intervals. The Pliocene-Quaternary section consists of clast-supported conglomerate to clayey sand that was deposited in two different ages, older and younger, of alluvial to fluvial environments.
The older of the two deformations is associated with the Sevier orogeny or associated central Nevada thrust belt and Nevadaplano. The Jurassic or Cretaceous Gass Peak thrust lies to the southeast of the quadrangle and the correlative Pahranagat and Mt. Irish thrusts are exposed to the north. In the quadrangle, this deformation is represented by one small reverse fault exposed in the north and tilting of the Paleozoic rocks. The angle across the Paleogene unconformity is about 35° in the northern and central parts of the quadrangle. A paleo-hill of Paleozoic rocks against which the Tertiary-Cretaceous sedimentary unit through the 22.56 Ma Harmony Hills Tuff are in buttress unconformity occurs in the northern part of the quadrangle. The presence of this paleo-hill suggests notable erosion. The second interval of deformation occurred in the Miocene-Quaternary as shown by normal-, oblique-, and strike-slip faults. The majority of these faults cut all of the exposed tuffs indicating that they are younger than the ~15 Ma Kane Wash Tuff. Based on crosscutting relationships, at least three ages of deformation occurred within the quadrangle: (1) 22.2 and 18.6 Ma, (2) 18.6 to 15.3 Ma, and (3) post 15 Ma. The major post-15 Ma structures are part of the NE-striking, left-lateral Pahranagat shear zone (a.k.a. Pahranagat fault system). Parts of each of three major left-lateral faults of that system are exposed: the Arrowhead Mine fault in the north, the Buckhorn fault in the center, and the Maynard Lake fault in the south. The km-scale Buckhorn syncline lies just north of the Buckhorn fault and folds rocks as young as the ~15 Ma Kane Wash Tuff. This syncline plunges gently NE and is an open fold. The Buckhorn syncline is interpreted as a fault propagation fold related to left-lateral slip along the Buckhorn fault based on subparallel orientations and timing. Small strike-slip duplexes occur along the Arrowhead Mine and Maynard Lake faults. Each duplex occurs near a bend in a strike-slip fault, which suggests that the duplexes accommodate changes in fault strike.
Partial support provided by the U.S. Geological Survey, National Cooperative Mapping Program award number G15AC00157, 2015.
A note from the authors (Department of Geoscience; University of Nevada, Las Vegas): We thank James Faulds and Angela Jayko for their support of this project. We also thank our valuable field assistants Jeremy Miera and Jeffrey Kinney.
Deal of the Week
Geology of Northern Nye County, Nevada
Mineral Resources of Northern Nye County, Nevada
Free delivery to the University of Nevada, Reno campus.
Message from BLM: We are pleased to announce a new, exciting position available at BLM – BUREAU OF LAND MANAGEMENT. It is our hope that qualified, career oriented individuals at your organization or other professionals known to you will actively consider this position and apply accordingly. Efforts on your part to disseminate this information are greatly appreciated.
Job Description: Environmental Protection Specialist;
Announcement Number: NM-DEU-2018-0027;
Location(s) of position: Carlsbad, NM, US;
Salary: (USD) $59,207 – (USD) $76,970;
Applications will be accepted until: 05/08/2018.
Research Scientist, Arizona Geological Survey
Are you an earth scientist with a focus in economic geology/ore deposits seeking to further your career in an academic and research environment? If so the Arizona Geological Survey (AZGS) would be a great place for you! AZGS has a new Research Scientist position available focused on economic geology and ore deposits. Principal duties of the position are to 1) develop a research program that will further the understanding of economic mineral resources of Arizona, congruent with AZGS charge to ‘encourage the wise and prudent use of Arizona lands and mineral resources’; 2) develop collaborative research and investigations with other university researchers, industry professionals and students; and 3) develop and enhance contacts with the mining and exploration geology community in Arizona. This position will provide opportunities to collaborate with researchers in UA Geosciences, the Lowell Institute for Mineral Resources, UA Mineral Museum, and UA Dept. of Mining and Geological Engineering, with access to state-of-the-art analytical facilities through these collaborations. Candidates should be enthusiastic individuals who can work independently, manage responsibilities, collaborate with other staff geologists, develop research proposals for external funding, and coordinate with industry to investigate economically important mineral resources.
Nevada Petroleum and Geothermal Society
Monthly Dinner Meeting
Thursday, May 3, 2018
SPEAKER: Jason Craig, Geologist, Student, University of Nevada, Reno [advisor, Jim Faulds, NBMG]
TOPIC: Discovery and Analysis of a Blind Geothermal System in Southern Gabbs Valley, Western Nevada
ABSTRACT: A systematic geothermal exploration program has been completed in southern Gabbs Valley as part of phase II of the DOE-funded Nevada play fairway project. Multiple geologic, geophysical, and geochemical data sets for the area have been integrated to characterize a potential blind geothermal system in the study area. A 7 km2 area with elevated 2-meter temperatures has been established in a complex structural setting at the intersection between Quaternary strike-slip and normal faults. Geothermometry of water samples taken 7 km northwest and down hydrologic gradient of the 2-meter temperature anomaly indicate subsurface temperatures of 130-140°C. Detailed gravity, magnetic, and magnetotelluric surveys provide controls on intrabasinal structure and support evidence for geothermal activity in the subsurface. Exploration of the system is ongoing and drilling of new temperature gradient holes is scheduled within the next few months to delineate the resource.
BIO: Jason grew up in Reno, Nevada and is the descendant of a family of geologists and miners. He spent his childhood exploring the rivers of the Sierra Nevada and the mountain ranges of the Great Basin, which instilled in him a deep passion for the outdoors and the natural sciences. Jason was a member of the U.S. Whitewater Kayaking Team for over a decade and won titles including Junior National Champion and World Champion. He earned his undergraduate degree in Geology from the University of Nevada, Reno in 2016. Jason is currently working towards completing his M.S. at the same institution in structural and geothermal geology later this year.
Tamarack Junction, Reno, NV
13101 S. Virginia St.
Reno, NV 89511
Cocktail Reception 6:30 PM; Dinner Served at 7:00 PM
Sponsored by Ormat Technologies
NPGS Members $25-$28; Non-Members $30-$33; Students $15
RSVP for the May Dinner Meeting by Tuesday, May 1, with the following link:
If you must cancel your reservation, please contact:
Jake Zachry, firstname.lastname@example.org
Tom Gallagher, email@example.com
Upcoming Meeting Dates:
Trexler Memorial Field Trip
Sep 7-10, 2018
More information will follow soon.
A message from Philipp Ruprecht (Assistant Professor, Geological Sciences, UNR):
Let me inform you that we have two more seminars this semester:
April 30—Roice Nelson, Jr. – Dynamic Measurement, LLC
Title: Lightning Analysis: Creating Geoframeworks
May 7—Daniela Pantosi (INGV, Italy) Slemmons Lecture
Title: The 2016 Earthquake Sequence in Central Italy: The Complexity of Normal Faults in Italy
Location: DMS 102 at University of Nevada, Reno (4 PM)