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:

Worthy Brewing (eastside location)

495 NE Bellevue Drive, Bend

In the Beermuda Triangle Room


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.

Presentations are also live-streamed through Zoom. Please see the presentation details for Zoom registration links. Zoom presentations are recorded whenever possible, 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

    • 25 Feb 2025
    • 5:30 PM
    • Online and in-person at Worthy Brewing

    Jill Marshall

    Portland State University











    In thin-soiled settings, we presume that trees play a significant role in converting rock into mobile sediment via physical weathering, with models centered on wind-driven tree throw. By combining novel force sensors at the tree-rock boundary with precipitation, solar radiation, wind, tree sway, and acoustic emission data, Jill Marshall has begun to quantify how species differences, wind, and root-water uptake contribute to tree-driven rock cracking. Her data suggests that changes in climate and forest structure may greatly influence tree-driven physical weathering and the rates at which trees grow their own soil pots.



    Please join us at:

    Worthy Brewing (eastside location)

    495 NE Bellevue Drive, Bend

    In the Beermuda Triangle Room


    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 Nov 2024 The Changing Skyline: Photo Documentation of 100 Years of Landscape Change in the Central Oregon Cascade Range
22 Oct 2024 Cascade Volcanoes: Past, Present, and Preparing for the Future
24 Sep 2024 Was the 1700 Cascadia earthquake one or many ruptures?
10 Jul 2024 On Basaltic Andesites: The Dominant Lava Type of the Central Oregon High Cascades
9 Jun 2024 COGS Picnic Social
28 May 2024 From the Last Glacial Maximum to Present: New Chronologies for Oregon’s Cascade Ice Cap and Glaciers
23 Apr 2024 Extensional Evolution of the Horse Range, Eastern Nevada
26 Mar 2024 Sediment-Hosted Lithium Deposits at McDermitt Caldera: Oregon’s Critical Mineral Capital
27 Feb 2024 How, Why and Where Earth Melts
23 Jan 2024 Onset and impacts of the c.7700 ybp eruption of Mount Mazama, Oregon
28 Nov 2023 Hydrology of High-Desert Springs in Eastern Oregon
24 Oct 2023 Sunstones: The Good, The Bad, & The Ugly (in other words, the complex petrogenesis of our state gemstone)
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