Arizona Geological Society


Upcoming events

    • 29 Sep 2023
    • 6:30 AM - 5:00 PM
    • Patagonia, Arizona - To be Announced
    Registration is closed


    South 32 Hermosa Project

    Santa Cruz County, Arizona

    Arizona Geological Society members are invited to join the field trip as we visit the world-class South 32 Hermosa Project in Santa Cruz County, Arizona. 

    Acknowledgements - The Arizona Geological Society Executive Committee thanks the South 32 staff for organizing the field trip to the Hermosa project. 

    Field Trip Leaders:  South 32 Geological Staff

    Location - Attendees will meet at a central location in Tucson (TBD) prior to departing for Patagonia at 6:45 AM.

    Field Trip Date/Time - Friday, September 29, 2023, 6:30 AM with a planned arrival at South 32's office in Patagonia at 8:00 AM.

    Group size - Limit 25:  South 32 has asked us to limit the number of field trip participants to 25 people.

    Field Trip Costs - Field trip is restricted to AGS members;  $35.00 for professional AGS members, and $10.00 for student members.  These fees will cover the cost of transportation, lunch and refreshments. South 32 will provide the field trip guidebook.  Information on lunch choices to follow; drinks and snacks will be provided.

    Carpooling - Due to limited space, AGS has decided to employ several vans to transport field trip participants from Tucson to the South 32 Hermosa project site.

    We anticipate that this trip will be highly popular, so in fairness to all we’ll use a lottery system to select participating members.  Of the 25 spots, we are reserving five spots for AGS student members. 

    For those interested in attending, please enroll at your earliest convenience at  Each enrollee will be assigned a number. Once registration is closed on 10 Sept., we’ll draw names and immediately inform registrants of their status.  No payment is due until you have been notified of your status.

    Registration Deadline for this event is 6 PM on September 10, 2023.

    We will establish a wait list in the event of cancellations.

    Meals - A selection of sandwiches, cookies, fruit, bottled water and sodas will be provided for lunch. 

    Liability Wavier - A Liability Wavier Form for all field trip participants can be downloaded at:

    Link -

    To expedite registration, participants are encouraged to bring a signed copy of this form with them on the morning of the field trip.  Additional copies will be available at the check-in for those who forget.

    MSHA Requirements - All field trip participants are required to wear steel-toed boots, hard hats and safety glasses.

    Contact Info - For questions, please reach out to either Paul Jensen ( or Mike Conway ( 

    • 03 Oct 2023
    • 5:30 PM - 8:00 PM
    • Hexagon Office at 40 East Congress Street, Suite 150, Tucson, Arizona 85701

    Arizona Geological Society

    2023 Speaker Series

    Tuesday, 3 October 2023 | 5:30 - 8:00 PM

    Location:  Hexagon Mining Division Office

    40 East Congress Street, Suite 150, Tucson, Arizona  85701

    Parking: On the street or parking garage (Old Pueblo Parking)

    Social Hour with Sandwiches from Beyond Bread (5:30-6:30 PM) Presentation (6:35 PM)

    For those unable to attend, remote broadcast begins at 6:35 PM. No registration or fee to attend remotely.

    Streaming URL forthcoming soon.

    The Arizona Geological Society thanks Freeport-McMoRan

    for Sponsoring the October 2023 Meeting

    The Arizona Geological Society also thanks Hexagon

    for generously providing the venue and drinks

    Structural Modeling for Reducing Uncertainty in Geologic Interpretations

    Amanda Hughes Ph.D.

    Assistant Professor of Practice, Department of Geosciences, University of Arizona

    Abstract: Geologists are often faced with the challenge of creating a complete interpretation for folds, faults, and fractures with data that are sparse and often ambiguous.  This often gives rise to multiple interpretations in some areas; these often have critical implications for practical decision-making in fields as wide-ranging as mineral and petroleum exploration and production, geothermal systems, seismic hazard assessment, and subsurface storage applications.  Various modeling approaches have been developed to apply quantitative constraints and reduce uncertainty to the process of geologic cross section and 3D model construction, including kinematic modeling, analog modeling, and numerical mechanical modeling approaches, including finite-element, distinct-element, and boundary-element models.  Each of these approaches have different strengths and drawbacks and therefore are most useful in different geologic circumstances; BEM models, for example, are most applicable to low-strain geologic settings, while more highly strained rocks would be more accurately modeled with other approaches.

    I will review the various types of modeling approaches currently employed by structural geologists, along with their benefits and disadvantages, and will then show a series of case studies where we have used these approaches to gain insight into the geometry and distribution of stress and strain in various geologic settings.  First, I will show the utility of applying boundary element mechanical models to predicting the distribution of stress and fractures around salt bodies in the Paradox Basin in Utah. Then, I will show how kinematic models can be used to constrain cross section interpretations using both surface geology , seismic reflection, and seismicity datasets from several case study locations in Utah, California, and offshore sedimentary basins. I will highlight how our recent work to make these kinematic modeling approaches more flexible and consistent with results from high-strain mechanical models allows them to be applicable and more easily applied to interpreting a wider range of geologic structures.  By doing so, I will show how integrating concepts and tools across these various approaches can help to improve our ability to constrain and test geologic models of the subsurface for a range of applications.

    Bio: Amanda Hughes is an Assistant Professor of Practice in the Department of Geosciences at the University of Arizona.  She holds B.S. degrees in Geology (2006) from Washington and Lee University and M.A. (2009) and PhD. (2012) degrees in Earth and Planetary Sciences from Harvard University.  She also has experience working in energy exploration and R&D for Chevron Energy Technology Company (2012-2016).  She teaches courses at the University of Arizona in Physical Geology, Structural Geology, Active Tectonics, Exploration Seismology, and Advanced Structural Geology Methods, and co-teaches professional courses on Structural Geology for Mine Geologists and Structural Geology for Geotechnical Professionals.  Her research is focused on understanding the growth of geologic structures through integrated observations from field geology, active tectonics, seismology, geophysics, rock mechanics and various modeling approaches.  She is also interested in developing and testing new quantitative approaches to observing and modeling geologic structures, and applying these methods to geologic problems in energy and mineral exploration, seismic hazard assessment, and regional tectonics.

    Hexagon Mining Division Office - 40 East Congress Street,

    Suite 150, Tucson, Arizona 85701

Past events

07 Sep 2023 Virginia McLemore presents Rare Earth Element (REE) Potential and Origin of the Cambrian-Ordovician Carbonatites and Episynites in soutbern New Mexico
24 Aug 2023 AZ Geological Society Social Mixer
15 Jun 2023 AZ Geological Society Social Mixer
02 May 2023 Lithospheric Controls on the Formation of Porphyry Copper Deposits: What could possibly go wrong?
04 Apr 2023 Temporal Evolution of the Rattlesnake Creek Terrane and Implication of Jurassic Construction of Crust in the Western United States
07 Mar 2023 Magmatism and Characteristics of Supergene and Hypogene Alteration-Mineralization of the Lone Star Porphyry Copper Deposit, Safford District, Arizona
17 Jan 2023 Arizona Geological Society Social Mixer
06 Dec 2022 Perspectives on a Carbon Storage Ecosystem Built from Distributed CO2 Sequestration Resources in Arizona
01 Nov 2022 Content Learning Outcomes from Geological Virtual Field Trips can Exceed those from In-person Field Trips
04 Oct 2022 Machine Learning, Robotic Mapping, and Particle Dynamics for Earthquake Geology
06 Sep 2022 Bell Copper's Big Sandy Copper Porphyry Discovery by Tim Marsh, Ph.D.
07 Jun 2022 An Overview of Mineralogy of Arizona 4th Edition by Dr. Ray Grant
03 May 2022 Helium Exploration and Exploitation in the Holbrook Basin, Arizona
16 Apr 2022 Spring Field Trip - Mountains, Mines and Structural Settings of the North and Central Altar Valley, Coyote Mountains to Sierrita Mountains, Pima County, Arizona
08 Mar 2022 Post-caldera Explosive Eruptions at the Valles Caldera (and Vulcano Island)
08 Mar 2022 Tour of University of Arizona's Alfie Norville Gem and Mineral Museum
02 Nov 2021 Arizona Geological Society Presents: Chris Osterman, PhD 417 Project, Globe, Gila County, Arizona A Native Silver Discovery
17 Sep 2020 AGS Zoom Social Hour
27 Aug 2020 Mark F. Coolbaugh Presents: Renaissance Gold Inc. on Silicon
04 Jun 2020 Darren Smith Presents: Mineralogy, Market, and Ashram, a Rare Earth Carbonatite Deposit
05 May 2020 Philip M. Persson presents: The Detroit City Portal A New Chapter in the Story of Sweet Home Mine, Colorado, Rhodochrosite Mining
12 Mar 2020 AGS March Gathering
04 Feb 2020 SME & AGS Joint Dinner Meeting - Hexagon Integrated Portfolios
14 Jan 2020 Vit Kuhnel Presents Fluid Mechanics Versus Fracture Flow
03 Dec 2019 Legacy of Cenozoic Volcanism in the Pacific Northwest: Emphasis on the High Lava Plains of Oregon
05 Nov 2019 Vanadium Deposits in Arizona
08 Oct 2019 AGS Meet and Greet, A Networking Event
10 Sep 2019 Kent J. McGrew presents In-Situ Recovery Basics
06 Aug 2019 Gregory J. Leonard presents The Planetary Perils and Economic Promise of Near-Earth Asteroids
08 Jun 2019 Spring Field Trip - Petrologic and Structural Evidence for Flat Subduction Tectonics in Santa Catalina Mountains and Vicinity
04 Jun 2019 AGS Meet and Greet, A Networking Event
07 May 2019 Bootprints in Bear Country: Discovery History and Geology of the Malmyzh Cu-Au porphyry cluster, Khabarovsk krai, Russia by Mac Canby - Senior President Exploration for Freeport-McMoRan
02 Apr 2019 Florence Copper: Copper Recovery Using In-situ Technology By Dan Johnson BSc, MSc, PE – Vice-President | General Manager, Florence Copper Inc.
05 Mar 2019 Sarah Elizabeth Baxter presents "Treasures of Arizona's Sky Islands: Geology and Mineral Resources of Coronado National Forest
05 Feb 2019 Jeffrey E. Post presents The Hope Diamond and Smithsonian National Gem Collection
08 Jan 2019 John Dilles presents - Using the Zonation of Trace Metal Geochemistry and Hydrothermal Mineralogy for Porphyry Copper Mineral Exploration
04 Dec 2018 David (Duff) Gold presents - Deep-Seated Volcanism and the Genesis of Diamonds
06 Nov 2018 William Wilkinson Presents - The Good, The Bad and The Ugly: Three Decades of Exploration
02 Oct 2018 Ihor Kunasz Presents - The Geology and Economics of Lithium
04 Sep 2018 Jim Reed Presents - Applying Geological Exploration Methods Towards the Location of Clandestine Gravesites
07 Aug 2018 Rhodochrosite: Red Treasure of the Rockies - The Story of the Sweet Home Mine
03 Jul 2018 Alison Jones Presents - Rafting through 2 Billion Years of Geologic Time
05 Jun 2018 Gary Huckleberry Presents - The Geoarcheology of Ancient Water Control in the Southwest: Lessons from the Past
01 May 2018 William B. White presents The Science of Caves and Cave Contributions to Science
21 Apr 2018 Spring Field Trip - Jerome - An Early Proterozoic Volcanogenic Massive Sulfide Deposit
03 Apr 2018 Volker Spieth and Stanley Keith Present - Finding Gold in the Kupferschiefer
29 Mar 2018 Future Home of the University of Arizona Gem and Mineral Museum
06 Mar 2018 Joe Wilkins, Jr. Presents - Piedras Verdes and Cuatro Hermanos, Sonora, Mexico - A Tale of Two Porphyries
06 Feb 2018 Paul F. Hlava presents Causes of Color in Minerals and Gemstones
02 Jan 2018 Peter L. Ward presents Bringing Peace to the Climate Wars
05 Dec 2017 Joellen Russell presents The Ocean's Role in the Climate of the Anthropocene
07 Nov 2017 Eric Sundquist presents Geological Perspectives on Carbon Dioxide, the Carbon Cycle and Carbon Management
03 Oct 2017 Lily Jackson presents Andean River Sediments as a Window into the Tectonic History of Ecuador
05 Sep 2017 Vic Baker presents The Influence of the 18th Century Enlightenment on the Natural Sciences
22 Aug 2017 AGS Meet and Greet, A Networking Event
11 Jul 2017 Andrew Zaffos presents Global Tectonics and Marine Animal Diversity
06 Jun 2017 Dan Johnson presents Introduction to the Florence Copper Project and In-Situ Copper Recovery
02 May 2017 Robert Glennon presents America's Water Crisis and What To Do About It
22 Apr 2017 Spring Field Trip - The Laramide-age Chilito Porphyry Copper Deposit
04 Apr 2017 David London presents The Nature and Origins of Internal Zonation within Granitic Pegmatites
07 Mar 2017 Derek J. Thorkelson presents The Precambrian Tectonic Connection between Yukon and Arizona
07 Feb 2017 Daniel Hummer presents Mineral ecology and evolution: Using large datasets to tell the story of the co-evolution of Earth and life
03 Jan 2017 David A. Sawyer presents Dating Geologic Time in the Cretaceous: Integrating Biostratigraphy, Isotope Geochronology, and Astrochronology in Sedimentary Deposits of the Cretaceous Western Interior Seaway
06 Dec 2016 John W. Ewert presents USGS Responses to Some Volcanic Crises and Eruptions Around the World
01 Nov 2016 Alexander Schauss presents Minerals, Trace Elements and Human Health
22 Oct 2016 Fall Field Trip - The Peach Spring Tuff and the Silver Creek Caldera, Northwestern Arizona
04 Oct 2016 Hamish Martin Presents Geology of the Resolution Cu-Mo Deposit, Superior Arizona
06 Sep 2016 Keith R. Long Presents No Bonanza from Cheap Oil
02 Aug 2016 Lee Allison Presents The Future of State Geological Surveys: the Arizona Case Study
05 Jul 2016 Don Applebee Presents Genesis of the Chilito Porphyry Copper Deposit
07 Jun 2016 Robert Hildebrand Presents Collisions, Slab Failure Magmatism and the Development of Cordilleran Batholiths
03 May 2016 Peter Modreski will present "Pegmatites: Mineralogy, Gemstones, Economic Geology, and maybe not quite the same Giant-Crystal Rocks you always thought they were"
30 Apr 2016 Spring Field Trip - An Introduction to the Pinal Schist in Southeastern Arizona
05 Apr 2016 Jordon Bright Presents Looking for an Ocean in the Desert, the Enigmatic Bouse Formation
01 Mar 2016 Peter R. Johnson Presents Tectonics and Mineral Deposits of the Arabian-Nubian Shield
02 Feb 2016 Dr. Karen Wenrich Presents The Ga-Ge Rich Apex Mine, Utah - A Tsumeb, Namibia Analogue
05 Jan 2016 Sarah Baxter Presents Calc-silicate Alteration and Ore Characterization, ASARCO Mission Complex, Pima County, Arizona
01 Dec 2015 Peter Smith Presents The Latest News from Mars
14 Nov 2015 Fall Field Trip - Northern Plomosa Mountains and Bouse Formation in Blythe Basin
03 Nov 2015 Karen Kelley presents The Giant Concealed Pebble Cu-Au-Mo Porphyry Deposit, Southwest Alaska
06 Oct 2015 Caleb King presents Eocene Hydrothermal Systems and Contrasting Hydrothermal Alteration in the Battle Mountain District, Nevada
01 Sep 2015 Carl Bowser presents The Genesis of the Kramer Borax Deposit, Rogers Lake, Mojave Desert, CA:
04 Aug 2015 Dan Lynch presents Volcanoes in the Back Yard
07 Jul 2015 Erik Melchiorre presents The Complex Geological History Recorded by Arizona Placer Deposits:
02 Jun 2015 Jan C. Rasmussen Presents - Arizona Mineralization through Geologic Time
05 May 2015 Gordon Haxel Presents - Alpine peridotite in the desert - Arizona's Laramide subduction complex
02 May 2015 Spring Field Trip - Oak Creek - Mormon Lake Graben
18 Apr 2015 Third Annual Arizona Geological Society Doug Shakel Student Poster Event
03 Mar 2015 Apollo 17 Astronaut and Former Senator Harrison H. Schmitt presents A Geological Visit to a Valley on the Moon
03 Feb 2015 Don Yurewicz Presents Assessing Unconventional (Continuous) Hydrocarbon Resource Plays
06 Jan 2015 Arend Meijer presents: Sulfide-rich Proterozoic Mafic Rocks and Arizona Porphyry Copper Deposits - A Connection?
02 Dec 2014 Victor R. Baker: Megafloods on Earth, Mars, and Beyond
15 Nov 2014 Fall Field Trip - Debris Flows Shape the Sabino Canyon Landscape - look out below!
04 Nov 2014 Isabel F. Barton: Historical Development & Current State of Geological Research in the Central African Copperbelt
07 Oct 2014 Apollo 17 Astronaut and Former Senator Harrison H. Schmitt presents A Geological Visit to a Valley on the Moon
02 Sep 2014 Lewis Land presents Evaluation of Groundwater Residence Time in a Karstic Aquifer System
05 Aug 2014 Jamie Molaro presents Thermal Stress Weathering in the Inner Solar System
01 Jul 2014 Jim Leenhouts presents Surface-water/groundwater Interactions in Arizona
03 Jun 2014 Arend Meijer presents Pinal Schist of So. Arizona--A Paleoproterozoic Fore-Arc Complex
06 May 2014 John C. Lacy presents The Genesis of Mining Law
26 Apr 2014 Spring Field Trip - Geology of the Christmas Porphyry Copper Deposit
24 Apr 2014 Second Annual Arizona Geological Society Doug Shakel Student Poster Event
01 Apr 2014 Eric Seedorff presents, Structural Dismemberment of a Porphyry Molybdenum System, Spruce Mountain District, Northeastern Nevada
04 Mar 2014 John Dreier presents, Copper Deposits of the Coast Ranges of Chile; A trip through time, space, and ore deposit nomenclature
04 Feb 2014 Ralph Stegen presents The Morenci Porphyry Cu-Mo Deposit, Greenlee County, Arizona: A Geologic Summary with Emphasis on Hypogene and Supergene Mineralization
07 Jan 2014 Steve Castor presents, Mountain Pass and other North American Rare Earth Element Deposits
03 Dec 2013 Stephen Jackson, USGS, Looking forward from the past: Ecological impacts of climate change through the lens of history
05 Nov 2013 Malcolm Siegel, PhD, MPH, LJS Consulting, Inc and School of Medicine, University of New Mexico, Albuquerque, NM. 87047: Uranium Mining in the American Southwest: Can Medical Geologists Ask the Right Questions?
04 Oct 2013 Field Trip - H. Wilson Sundt Generating Station
01 Oct 2013 Mark Logsdon, Principal Geochemist, Geochimica, Inc.: What Does “Perpetual” Management and Treatment Mean? Toward a Framework for Determining an Appropriate Period-of-Performance for Management of Reactive, Sulfide-Bearing Mine Wastes
01 Oct 2013 Mark J. Logsdon, Geochimica, Inc., Does acid-rock drainage lead to waste-rock instability? Geological, hydrological, and geochemical framework for the Questa Mine
03 Sep 2013 Pete Reiners, UA, Geosciences Dept., Geochronology of secondary Fe & Mn oxides in bedrock
30 Aug 2013 Field Trip - University of Arizona Tree-Ring Research Laboratory
06 Aug 2013 Bill Stavast, Freeport-McMoRan Copper & Gold, The Safford Mine: What we have learned since production began
02 Jul 2013 Lukas Zurcher, USGS, presents: "Tectono-magmatic evolution of the Central Tethys Region"
04 Jun 2013 Steve Van Nort presents, "Gold Fever! The BRE-X/Busang Story
07 May 2013 Federal lands and mineral resources: Colorado Plateau uranium deposits and the Sonoran Desert Heritage
18 Apr 2013 First Annual Arizona Geological Society Doug Shakel Student Poster Event

Copyright © 2013 Arizona Geological Society
Powered by Wild Apricot Membership Software