GSN Lecture in Elko—Jim Faulds—September 18—TONIGHT

Jim Faulds will be the speaker for the first Fall meeting of the GSN Elko chapter. If you have any questions about this meeting, please contact Gabe Kassos, GSN Elko Chapter Secretary (gkassos@klondexmines.com).

What: Geological Society of Nevada, Elko Chapter Meeting

Speaker: Dr. James E. Faulds, Nevada Bureau of Mines and Geology Director and State Geologist, University of Nevada, Reno, jfaulds@unr.edu

Topic: Favorable structural settings of active geothermal systems in the Great Basin region: Implications for fluid flow, normal faulting mechanics, and geothermal and epithermal mineral exploration

Date: Thursday, September 18, 2014

Time: The doors open at 6 pm and the talk begins at 7 pm.

Location: Western Folklife Center, 501 Railroad St. in Elko

Sponsor: This month’s meeting is sponsored by Coeur Products.

Abstract: Active amagmatic geothermal systems of the Great Basin, USA are used to generate electricity and have temperatures overlapping formation of some epithermal mineral deposits (up to and >200°C). We recently completed an inventory of structural settings of known geothermal systems (426 total) in the extensional Great Basin region. Of ~250 categorized fields, step-overs or relay ramps in normal fault zones are the most favorable setting, hosting ~32% of the systems. Such areas have overlapping fault strands, increased fracture density, and thus enhanced permeability. Other common settings include a) normal fault tips (25%), where horse-tailing generates closely-spaced faults and increased permeability; b) fault intersections (22%), where multiple minor faults typically connect major faults and fluids can flow readily through highly fractured, dilational quadrants; and c) accommodation zones (9%), where oppositely dipping normal fault systems intermesh in belts of multiple fault tips and intersections. 3D modeling indicates subvertical conduits of high fracture density in these settings. The primary segments of major faults only host ~1% of the geothermal fields. Quaternary faults lie within or near most fields.

The paucity of geothermal systems along primary fault segments may result from reduced permeability in thick clay gouge and periodic stress release in major earthquakes. Step-overs, terminations, intersections, and accommodation zones represent critically stressed areas, where fluid pathways more likely remain open in breccia-dominated fracture networks. Because stress is not relieved by major earthquakes, abundant microseismicity characterizes fault interaction areas, which precludes pervasive healing of fractures and thus facilitates fluid flow. Increased pore-pressure may also provide a positive feedback mechanism that promotes more frequent but lesser magnitude earthquakes. The association of some young (<5 Ma) epithermal mineral deposits in normal fault footwalls (e.g. Florida Canyon, Wind Mountain, and Hycroft-Lewis) with active geothermal systems in the hanging walls suggests recurrent activity and/or longevity for some hydrothermal systems. These data are relevant to understanding the mechanics of normal faulting and in guiding both geothermal and mineral exploration.

Earth Science Week Field Trips – October 11-12

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Photos from a previous Earth Science Week field trip led by Jon Price and DD Lapointe / photo credit: Charlotte Stock, NBMG

 

Save the date! To celebrate Earth Science Week this year, Jon Price and DD LaPointe will be leading field trips for the public on October 11 and 12 (Saturday and Sunday) in the Carson City area.

There will also be additional activities in Reno throughout the week. More details on all of these activities will be coming soon.

Detour Access to GBSSRL—September 4 through 15

Due to road/sidewalk construction, the west entrance to the Raggio parking lot in front of Great Basin Science Sample and Records Library (GBSSRL) will be closed September 4 through 14, 2014.

You will need to access parking for GBSSRL from the rear of the building. Please follow the detour route marked in yellow on the map linked on this page.  We are sorry for this inconvenience.

Job Announcement—Arizona Geological Survey

Message forwarded from Jim Faulds, NBMG Director and State Geologist:

From: aasgmembers, On Behalf Of Lee Allison
Sent: Thursday, September 04, 2014 8:09 AM
Subject: [AASG]: Position opening: Deputy Director, Arizona Geological Survey

Colleagues, we have opened a new position at AZGS for a Deputy Director.  I would appreciate your sharing the announcement with potentially interested parties.  Thanks very much.

http://www.azgs.az.gov/employment_deputy_director.shtml

LA

Lee Allison
State Geologist & Director
Arizona Geological Survey
416 W. Congress, #100
Tucson, AZ 85701
+1 520 209 4121
lee.allison@azgs.az.gov
www.arizonageology.blogspot.com

NPGS Monthly Dinner Meeting: Long-Term Performance of the Nevada Flash-Type Geothermal Projects – September 4, 2014

A note from NPGS: Come join NPGS at the Ramada on Thursday, September 4th–Dick Benoit, a geothermal resource consultant, will be speaking about the resources of five flash-type power plants in Nevada.

Nevada Petroleum and Geothermal Society Monthly Dinner Meeting:  Thursday September 4, 2014 (6:30 PM)
Where:  Ramada Reno Hotel, 1000 E 6th St, Reno, NV
Speaker:  Dick Benoit, geothermal resource consultant
Title:  Long-Term Performance of the Nevada Flash-Type Geothermal Projects

Abstract: Five flash-type power plants utilizing evaporative cooling have operated on different Nevada geothermal fields for periods of 21 to 28 years with varying degrees of success.  The Dixie Valley and Beowawe projects represent long-term successful projects that have operated at capacity factors generally above 85% and have power plants and resources well matched in size.  At Beowawe, the resource pressures and artesian flow rates have naturally increased to sustain output while temperatures have substantially declined.  At Dixie Valley, an augmented injection program was needed to stabilize resource pressures and flow rates while the temperatures have suffered modest declines.  The Bradys power plant has been the least successful project due to major reservoir cooling.  Bradys represents a case of a large liquid volume plant sited on a small resource.  The Desert Peak dual flash plant was replaced with a larger binary power plant after operating for 20 years and the project now consists of a medium-sized plant on a relatively small resource that has recently been declining in output.  The flash plant at Steamboat Hills is one of seven Steamboat plants located on a large reservoir.  It is now closely integrated with a binary power plant, and represents a successful case of a small plant located on a large resource.

About the speaker: Dick Benoit began working in the geothermal industry in Nov. 1973, after graduating from the University of Montana with a MS degree in Geology and has worked on many of the geothermal fields in Nevada during either the exploration phase or as a resource manager during production.  Dick is currently a geothermal resource consultant.

Where: Ramada Reno Hotel, 1000 E 6th St, Reno, NV
Skyline Room
When: Open Bar hosted by Barbour Well opens at 6:30 p.m.
Dinner is served at 7:00 p.m.
Presentation begins at 7:30 p.m.
Cost: Members: $20, Non-Members: $23, Students:  $10

Please RSVP no later than Tuesday, September 2nd at 5:00 p.m., using this link:
https://docs.google.com/forms/d/17R8-dWy4pRakNS_geGkPDhWT8HOpIcRSXT0QIbk6xuY/viewform
No shows will be asked to pay for dinner as NPGS will be charged. Please call Judy Kareck at 827-6111 if there are issues.

Department of Geological Sciences and Engineering Fall Seminar Series

This lecture series is sponsored by the Department of Geological Sciences and Engineering, College of Science, Mackay School of Earth Sciences and Engineering at the University of Nevada, Reno.

Unless otherwise noted below, these lectures are held on Mondays from 4:00 to 5:15 p.m. in Davidson Math and Science Center (DMS) 105.

If you have any questions, you may contact Dr. Stacia Gordon:
phone (775) 784-6476
staciag@unr.edu

8/25/2014 – Paula Noble, UNR

9/1/2014 – Labor Day

9/8/2014 – TBA

9/12/2014 (Friday) – Rina Schumer, DRI

9/15/2014 – Yang Zhang, UNR MS student

9/22/2014 – Geoff Blewitt, NBMG

9/29/2014 – Amanda Keen-Zebert, DRI

10/6/2014 – TBA

10/13/2014 – Professor Ze’ev Ronen, Professor, Ben Gurion University

10/20/2014 – GSA

10/27/2014 – TBA

11/3/2014 – Ken Adams, DRI

11/10/2014 – Macario Rocha-Rocha, UNR, PhD student

11/17/2014 – Danielle Molisee, UNR, MS student

11/24/2014 – Thanksgiving week

12/1/2014 – TBA

12/8/2014 – TBA

2015 Nevada Geology Calendar – coming soon

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Photo from 2014 Nevada Geology Calendar taken by Matthew Richardson.

Coming soon! You can look forward to another great Nevada Geology Calendar this year. This calendar is designed by Jack Hursh, Jennifer Vlcan, Chris Henry, and Nick Hinz and will be available this Fall 2014. More details will be coming soon.

This 12-month calendar for 2015 will feature a different geologic topic each month. It is full of beautiful photos highlighting Nevada’s scenic wonders and also includes interesting facts about Nevada geology.

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