Monthly Presentations

The Central Oregon Geoscience Society holds regularly scheduled monthly presentations on the 4th Tuesday of each month, from September to November, and from January to May. All presentations are free and open to the public.


Please join us at Bridge 99 Brewery:

63063 Layton Avenue, Bend

5:30 pm social hour

7:00 pm presentation


Please join us for the social hour before the presentation -- all are welcome! 

Presentations are also live-streamed through Zoom. Please see the presentation details for Zoom registration links. Zoom presentations are recorded whenever possible, please see the list of past presentations to watch recordings of past talks.

Visiting Scholar Presentations

Visiting Scholar presentations are scheduled during various times outside the regular monthly meeting schedule. Please check the schedule below for updates, or join the COGS email list for updates. To join the email list, go to the Join us page.



Upcoming Presentations

    • 24 Oct 2023
    • 5:30 PM
    • Online and in-person at Bridge 99 Brewery

    Emily Cahoon

    Oregon State University












    5:30 pm social hour

    6:00 pm student poster session

    7:00 pm presentation


    Sunstones are copper-bearing and gem-quality plagioclase crystals found within basaltic lavas in eastern Oregon. Native copper is visible as macroscopic platelets within the crystals and evidence suggests it partitioned magmatically into the crystal structure during growth. Lava flows containing sunstones are situated within the spatial footprint of the Columbia River Basalt Group (CRBG), the worlds youngest continental flood basalt. This has led to the assumption that sunstones are petrogenetically linked to the CRBG, as nearby CRBG lavas often contain coarse plagioclase phenocrysts. This connection however is unconfirmed, and ages for sunstones and hosting basaltic groundmass indicate they were emplaced during two temporally discrete eruptive events. In this talk, we explore the eruptive timing, spatial distribution, and geochemical homogeneity of these copper-bearing plagioclase crystals -- giving insights on the magmatic plumbing systems and melt segregation processes within flood basalt provinces. Dr. Emily Cahoon will also highlight aspects of these ethically sourced gemstones and the copper inclusions that make them unique.


    Oregon State University student poster session at 6:00 pm:

    Join us before the talk for a student poster session from three OSU students working with Dr. Emily Cahoon on various aspects of sunstone research. Each of these students was a recipient of a 2023 COGS student research grant.

    Kyle Nunley: Argon geochronology on basalt and hosted sunstones in eastern Oregon

    Scott Toney: Sunstones: A gemstone formed by a magmatic or hydrothermal process?

    Cheyenne Yost: Copper and lithium diffusion analysis of eastern Oregon sunstones


      


      


    Please join us at Bridge 99 Brewery:

    63063 Layton Avenue, Bend

    5:30 pm social hour

    6:00 pm student poster session

    7:00 pm presentation

    COGS talk are free and open to the public -- all are welcome! Please join us for the social hour before the presentation.

    All presentations are also live-streamed through Zoom. There will be a registration link at the top of this page as we get closer to the date of this presentation.

    • 28 Nov 2023
    • 5:30 PM
    • Online and in-person at Bridge 99 Brewery

    Hank Johnson

    U.S. Geological Survey






    5:30 pm social hour

    7:00 pm presentation


    Throughout eastern Oregon, small springs often are the sole source of water for wildlife and livestock for many miles, yet their hydrology is poorly understood. Most springs are known only as points on decades-old maps or unattributed features in geospatial data sets. Predicting their continuing viability as water resources during the on-going and future droughts poses a challenge to land management agencies. This talk focuses on the work done since 2015 to better understand the distribution and behavior of springs across eastern Oregon, and to predict their hydrologic response to changing precipitation by combining repeat field observations, water chemistry, and Landsat imagery.


    Please join us at Bridge 99 Brewery:

    63063 Layton Avenue, Bend

    5:30 pm social hour

    7:00 pm presentation

    COGS talk are free and open to the public -- all are welcome! Please join us for the social hour before the presentation.

    All presentations are also live-streamed through Zoom. There will be a registration link at the top of this page as we get closer to the date of this presentation.

Past Presentations

26 Sep 2023 Live Tour of the JOIDES Resolution
23 May 2023 Looking down to look ahead: How Oregon’s fossil rodents can help us understand the impacts of past and future climate change
25 Apr 2023 In the Shadow of Volcanoes
28 Mar 2023 The Most Recent Earthquake on the Mount Hood Fault Zone, Oregon: Implications for cascading earthquake, landslide, & flood multi-hazards in the Columbia River Gorge
28 Feb 2023 Ancient Soils of Earth and Mars
24 Jan 2023 The ancient magnetic field: Clues hidden in lava flows from around the world
22 Nov 2022 The development of the science of geology and the growth of the railroad industry: How geology played a significant role in railroads of the Pacific Northwest
25 Oct 2022 The Rock Bottom of Antarctica’s Food Chain
27 Sep 2022 Paleoseismic investigations of Quaternary active faults in the forearc and backarc of the central Pacific Northwest
22 Sep 2022 Evidence of humans in North America during the Last Glacial Maximum
28 Jun 2022 Volcanoes! Travelogue and Science of Two Volcanic Arcs
24 May 2022 Encountering the Unexpected in Pacific Northwest Geology
26 Apr 2022 When Magmas Meet High-Tech Metals: What Can the Mountain Pass Rare Earth Element Deposit Bring to the Future?
22 Mar 2022 Newberry Volcano Geothermal Projects, Past and Future
22 Feb 2022 From maar craters to cinder cones: Understanding Oregon's small, but most common, volcanoes
25 Jan 2022 Wildfire and Debris Flows
23 Nov 2021 Tectonic evolution of the Cascadia margin in southwest Oregon during the past 55 million years
26 Oct 2021 Evaluation of slip history and Holocene activity on faults in the Strawberry Mountains
28 Sep 2021 Timing and controls on growth of the Oregon Basin and Range Province
25 May 2021 I Date Rocks: A Geochronology Love Story
27 Apr 2021 Water in the Deschutes Basin: 2020 Hindsight – What Happened?
23 Mar 2021 The fragmented death of the Farallon Plate
23 Feb 2021 Our Vanishing Glaciers, Part II
26 Jan 2021 The Next Great Cascadia Earthquake - How did we get here?
24 Nov 2020 What lies under recently active Cascades volcanoes?
27 Oct 2020 Mapping the Magmatic Pathways Beneath Volcanoes from Newberry, Oregon to Santorini, Greece
22 Sep 2020 Red Rocks from Earth to Mars
25 Jun 2020 Extinction: Using catastrophic events to construct the geologic timeline
26 May 2020 The history and science of glacier change in the western US and a peek into their future
28 Apr 2020 Volcanoes in Our Backyard: Understanding and Mitigating Volcano Hazards in Central Oregon
24 Mar 2020 I Date Rocks: A Geochronology Love Story
25 Feb 2020 Mountains, Earthquakes, and Landslides: Using Lasers to Peer Behind Cascadia's Green Veil
28 Jan 2020 Three Newly Discovered Fault Systems in Oregon
26 Nov 2019 Oregon's Checkered Past
22 Oct 2019 The Other Flood: Ice-age Bonneville Flood on the Snake River
24 Sep 2019 Tectonic History of the Coos Bay Basin and its Relationship to Pacific Northwest ‘Siletzia’ Tectonics
10 Aug 2019 Newberry Volcano: A sleeping giant with two bubbling lakes
28 May 2019 Holocene Glacial and Paleoclimate Reconstructions in the North Cascades, Washington
23 Apr 2019 A new look at “old” tuffs from Newberry Volcano: Evidence for dynamic magmatic processes at a geologic crossroads in central Oregon
26 Mar 2019 Kīlauea's 2018 Fissure Eruption – Chronology, Processes, and Impacts of Kilauea's Largest Eruption in 200 Years
26 Feb 2019 Mountains, Earthquakes, and Landslides: Using Lasers to Peer Behind Cascadia's Green Veil
22 Jan 2019 The High Lava Plains of Oregon: Volcanic and Tectonic Connection between Yellowstone and the Cascades
27 Nov 2018 Groundwater hydrology and groundwater-dependent ecosystems of central Oregon
23 Oct 2018 The Crooked River Caldera
25 Sep 2018 Assembling the Northwest: A roadside view of Oregon and Washington geology
16 Jul 2018 Oregon's volcanoes: What have we learned from global advances in volcanology over the past decade?
22 May 2018 Oblique subduction, rotating crustal blocks, and the active tectonics of the Pacific Northwest
24 Apr 2018 Mount Hood: Confessions of an interesting Boring volcano
27 Mar 2018 Geothermal Exploration at Newberry Volcano

Central Oregon Geoscience Society

Email: COGeoSoc@gmail.com
P.O. Box 2154,  Bend, Oregon 97709

Powered by Wild Apricot Membership Software