Arizona Geological Society


Upcoming events

    • 06 Aug 2019
    • 6:00 PM - 9:00 PM
    • Sheraton, 5151 E Grant Rd. (& Rosemont), Tucson AZ 85712

    Sponsored by:  TBA

    The Planetary Perils and Economic Promise of Near-Earth Asteroids

    by Gregory J. Leonard,
    Lunar & Planetary Laboratory, Department of Planetary Sciences, University of Arizona

    Abstract: Near-Earth Objects (NEOs) primarily include asteroids (NEAs) whose orbits bring them into close proximity to Earth; NEAs have been pummeling our planet since its formation ~4.5 Gy ago. Although asteroid impacts are sparsely recorded in the geologic rock record, they have profoundly affected Earth’s biologic evolution, variably bringing life-essential compounds to Earth (e.g. H2O, amino compounds) or severely disrupting widespread biotic communities. Large NEAs, ~100m to >1000m diameter continue to pose regional to global-scale threat; and despite being low probability events, they are high consequence.

    Juxtaposed with the narrative of NEAs as a planetary threat NEAs are mineral-rich and compositionally diverse, this gleaned from thousands of geochemical evaluations of their offspring meteorites. NEAs range in composition from naturally-alloyed Fe-Ni-Co stainless steel (M-type) to organic carbon- and water-rich bodies (C-Type) reflecting their primitive pre-planetary solar nebula makeup. The mineral-rich inventories of NEAs render them attractive targets for future exploration and mining exploitation. For example, the often-touted inventories of PGMs contained within the NEA population, including Pt-Pd-Os-Ir-Rd are measured in billions of tonnes, with present (Earth surface) values measured in quadrillions of $US. However, the compound of primary exploitation interest will be water required for rocket fuel, servicing Earth orbiting satellites and spacecraft, and for deep space exploration. The importance and necessity of extracting asteroidal metals for space-based construction, particularly ultra-pure iron will logically follow establishment of space-based fuel sources. Additionally, by virtue of their ‘near-Earth’ orbital character, many NEAs are energetically less costly to visit than the moon, further amplifying their appeal. However, considering the micro-gravity, hard vacuum, and extreme temperature environments within which NEAs exist, development of novel mineral exploration, extraction, and transport technologies are required for exploitation.

    Understanding the population, distribution, and character of NEAs begins with their discovery and tracking. The Catalina Sky Survey (CSS) is a NASA-supported project, managed under NASA’s Planetary Defense Coordination Office. Since its formation in 1998 CSS has discovered nearly half of all known NEAs (current total ~20,500 objects). CSS operates four telescopes in the Santa Catalina mountains north of Tucson, Arizona where astronomers both discover and track NEAs. Longstanding success of the project is attributed to CSS’ comprehensive sky coverage, continued development of innovative software and the detection pipeline, and the inclusion of real-time human attention to the NEO discovery and tracking process.

    I will review the basic character and properties of the NEA population, how they are discovered and tracked, and discuss their dichotomous role as both agents of planetary change to their existence as mineral-rich bodies available to humans in support of future space exploration.

    Bio: Gregory Leonard is a field geologist, planetary scientist, and glaciologist who has provided research and consultation services for industry, government, and academia for 30 years. He holds BSc and MSc degrees in Geosciences and Geography from the University of Arizona. He is currently a Senior Researcher in the Department of Planetary Sciences at the University of Arizona and associated with the NASA-funded Catalina Sky Survey, the world's most productive Near-Earth Object (NEO) survey where he has discovered >750 near-Earth asteroids and 4 comets. His current research also includes Mars and Mercury geologic studies, and planetary analog studies. His initial training with NEO surveys began with the USGS Branch of Astrogeology (Flagstaff, AZ) in the early 1990s working under the mentorship of Gene and Carolyn Shoemaker at the Mt Palomar Observatory, California. 

    Prior to his return to planetary sciences Gregory conducted multispectral satellite-based remote sensing and field investigations of glacierized terrains for the Global Land Ice Measurements from Space project (GLIMS). He has explored on glaciers in Alaska, the Cascades, the Andes, the Nepalese & Indian Himalayas, and the Mongolian Altaids. He has co-authored many publications on alpine glacier responses to climate change, glacier-related mountain hazards, and seismic-induced landslides.

    Additionally, he has vast experience in the mineral exploration industry in North America, Asia, and the Asia-Pacific region. He has extensive field geologic and project management experience and has contributed to the discovery of world class precious and base metal deposits in Indonesia (Gosowong low-sulphidation epithermal Au-Ag deposit) and Mongolia (Zuun Mod porphyry Mo-Cu deposit). He now dreams of the day when a rewarding geologist’s career includes near-Earth asteroid prospecting. 

Past events

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

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