www.unr.edugeothermal

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www.unr.edu/geothermal
Resource Exploration, Assessment and
Research Lisa Shevenell, Mark Coolbaugh, Chris
Sladek, Rick Zehner, Chris Kratt GEA -
Geothermal Issues and Outlook Workshop October
4, 2008
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Great

• Focus
• Applied Geoscience Research
• Conventional Hydrothermal Systems
• Collaboration w/DOE, Industry Navy
• Education of Students for Workforce
• Database Development, Maintenance and Serving on
  the Web

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Assessment for Nevada

• GRC Bull, June 2008 (Shevenell, Morris,
  Blackwell)
• Preferred values _at_ known systems
• Permits
• Heat Loss
• GeothermEx PIER
• WGA
• Nominal 5 MW assumption
• Minimum 2170 MW _at_ 160 sites

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New Exploration and Assessment Methods On-going
Research

• Conducting regional studies to develop models and
  build geothermal potential maps local studies to
  better understand systems

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Gravity, Dilation, T-grad, Seismicity
Coolbaugh, et al.
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Detailed Mapping in Modern Plate Tectonic Context
Desert Peak
Overlapping Normal Faults

• En echelon NNE normal faults
• Subvertical conduits
• High fracture density
• Multiple step overs
• Other favorable settings
• Terminations of range-front faults (Gerlach)
• Intermeshing opposing systems (Salt Wells)

Faulds
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Recent discoveries of a number of previously
unknown geothermal systems in the Great Basin
suggest that a large undiscovered resource base
does in fact exist.
McGinness Hills Tungsten Mountain Astor
Pass Smoke Creek Desert Pyramid Rock Rhodes
Marsh Salt Wells north
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Remote Sensing for mapping mineralogy and thermal
anomalies
Hymap 3-5 meter
Kratt, Calvin
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ASTER delineates borates in SW Nevada

• locate systems without hot springs issuing at
  surface

ASTER color Composite image
Kratt, Coolbaugh
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Rhodes Marsh, Mineral County, NV. Red
strike slip fault Black normal fault
Soda Springs, 112 geotherm.
X
Active range front faulting
opalized sands
springs/wells
Warm well with borates 155 / 162
geotherm. sampled 2005
Coolbaugh, Kratt, Zehner, Sladek
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New Assessment Methods Shallow Temperature
Surveys
Sladek, Zehner, Kratt, Coolbaugh, Penfield
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Tungsten Mountain discovered during Au
exploration drilling in 2005,
2006 (information provided courtesy NewCrest
Resources, Tom Kilbey) - northwest side of
Edwards Creek Valley, Nevada - geothermal
system occupies possible step-over in range
bounding fault

• All 23 exploration holes hit hot water, with
• temperatures ranging from 50-95C, often with
  steam, at
• depths of 90-275 m
• Hot water encountered over 2 km strike length,
  open in
• all directions
• - Geothermometers 174C Na-K-Ca-Mg 177C quartz

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Kratt, Zehner, Penfield
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Teels Marsh December 2007
Kratt, Zehner, Penfield
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Temperatures (C) From Cold Springs
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New Discoveries

• Astor Pass RS, TS
• Blue Mountain GE
• Bonham Ranch RS, TS
• McGinness Hills GE
• Rhodes Marsh RS, TS
• Salt Wells (better defined) TS
• Teels Marsh RS, TS
• Tungsten Mountain GE, TS

GE Gold Exploration RS Remote Sensing
TS Temperature Surveys
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Proposed Work

• 4 current proposals
• 2 in the process of award
• Sites Aurora, BR 16, Colado, Cove Fort,
  Hawthorne, Lee-Allen, NY Canyon, Patua, Salt
  Wells, Stillwater, Surprise Valley
• Sponsors
• Enel, North America
• Navy GPO
• NREL
• Vulcan

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Proposed Work

• Data gathering, assimilation, GIS
• Evaluate active faulting - LSA photography
• GPS to assess geothermal targets modeling
  crustal stress
• EQ Monitoring
• Field Recon

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Proposed Work

• Geochemistry
• Mapping geothermal features
• Rock characterization rock mechanics
• 3-D Seismic
• Shallow T-surveys
• Structural mapping and analysis

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Conclusions

• Research has enabled the development of
  significant new evaluation and exploration tools
• New tools helping to identify new geothermal
  resources and better assess existing ones
• Undiscovered resource base in the GB is
  significant but unknown need assessment
• Geothermal energy has the potential to be a major
  contributor to renewable energy portfolios in NV

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Silicified sediments (opal)
All blind geothermal systems in Nevada that
are currently producing electricity have some
surface signatures
Carbonate tufa/travertine
Clay alteration
Borate and sulfate evaporites
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