Tuesday, September 28

College of Earth, Ocean, and Atmospheric Sciences

Oregon State University

Timing and controls on growth of the Oregon Basin and Range Province

Extension and stretching of the North American plate created the Basin and Range physiographic province in western North America. The northwestern part of this province in northern California and Oregon lies in the backarc of the Cascadia subduction zone, a region characterized by rotational deformation. This presentation will examine the opening and expansion of the Oregon Basin and Range province and the resulting tectonic forces that have shaped central Oregon and the Cascades. Click here for more...

Tuesday, November 23

Rebecca Dorsey

Department of Earth Sciences, University of Oregon

Tectonic evolution of the Cascadia margin in southwest Oregon during the past 55 million years

Sedimentary and volcanic rocks in southwest Oregon record a complex history of subduction, accretion, sedimentation, rotation, and uplift at the Cascadia convergent margin over the past ~55 million years. This presentation will integrate knowledge from legacy datasets with ongoing studies to share insights into tectonic events and processes that have shaped the Cascadia forearc region through Cenozoic time. Click here for more....

Tuesday, May 25

Andrea Balbas

California State University - Long Beach

I Date Rocks: A Geochronology Love Story

Rocks are amazing in that they offer us a window into the past and tell stories that can be beyond human imagination. This allows us to understand Earth processes that we have not directly witnessed. A key to unraveling the possible cause and nature of such processes is an understanding of their timing and pacing. This is the power of geochronology. From the order of a stratigraphic sequence to the radiometric ages of lava flows, geologists have continued to invent and develop new ways for determining when something occurred in Earth’s past. For me, getting new ages from rocks is like taking a trip back in time and that is why I love it.

Tuesday, April 27

Kyle Gorman, Region Manager, Oregon Water Resources Department

Water in the Deschutes Basin: 2020 Hindsight – What Happened?

In the fall of 2020 the Deschutes River took on a cloudy green color from silt scoured from the bottom of Wickiup Reservoir. Water levels reached unprecedented lows as the reservoir was drained for the first time since the dam was built in 1949. In this presentation Kyle Gorman, Regional Manager for the Oregon Water Resources Department, will reflect on what happened in 2020 and the projections for water resources in 2021.

Click HERE to watch the recorded presentation

Tuesday, March 23

William Hawley, Lamont-Doherty Earth Observatory

The fragmented death of the Farallon Plate

Could volcanism in central Oregon be linked to a hole in the subducting plate beneath North America? In this presentation William Hawley from the Lamont-Doherty Earth Observatory will discuss evidence for tearing of the subducting plate as it descends into the mantle beneath central Oregon and the impacts this has on surface processes, including volcanism and earthquakes in Oregon.

Scientific American article: We Could Be Witnessing the Death of a Tectonic Plate

National Geographic article: A tectonic plate is dying under Oregon. Here’s why that matters

Click HERE to watch the recorded presentation

Tuesday, February 23

Anders Eskil Carlson, President and Chief Scientist, Oregon Glaciers Institute

Our Vanishing Glaciers, Part II

Almost a century ago, scientists and mountaineers in Oregon observed the retreat of Oregon’s glaciers and raised alarm over the potential for an ice-free Oregon in the not too distant future. That future has now arrived. The recently founded Oregon Glaciers Institute (OGI) is monitoring changes in Oregon’s endangered glaciers with the goal of projecting their viability. OGI recently concluded a state-wide survey of how many glaciers remain in Oregon with an estimate of how many existed more than 60 years ago when the last such census was conducted. In this presentation, we will look at the implications of these findings and why such changes are occurring (including Oregon’s geology and climate change), with a final note on how one can help in preserving Oregon’s vanishing glaciers.

Click HERE to watch the recorded presentation

Tuesday, January 26

Chris Goldfinger, Oregon State University

The Next Great Cascadia Earthquake - How did we get here?

Our understanding of plate tectonics is only about 60 years old, and we are still low on the Earth's learning curve. Cascadia earthquakes helped usher in a new hypothesis of everything, but then was forgotten for many years. More recently, our understanding of Cascadia earthquakes suddenly went from unknown, to a potential generator of M9 earthquakes in just a few short years. How did this happen, and what does the future hold?

OPB article: The Big One, Times 2: Research Shows Cascadia Quakes Sometimes Trigger San Andreas Fault

Oregon Field Guide: Unprepared: An Oregon Field Guide Special

Click HERE to watch the recorded presentation

Tuesday, November 24th - Online Zoom Presentation

6:45PM "doors" open <-> 7:00PM presentation

Leif Karlstrom, University of Oregon
What lies under recently active Cascades volcanoes?

Although the skyline and highest topography in the Cascades volcanic arc is dominated by a dozen or so large stratovolcanoes, a vast number of smaller volcanoes (roughly 3000) have erupted in the geologically recent past and might be considered the 'dominant' expression of volcanism. An outsized proportion of these small volcanoes occur in the central Oregon Cascades. I'll talk about my work on a few outstanding questions in the field of volcanology, applied to the Cascades: What controls where volcanic eruptions happen? Why are there so many small volcanoes and so few large ones? Are there subsurface indicators that help us to understand which have been most active in the past, or might become active in the future?

Recent article in the Bulletin: Study finds volcanoes more prevalent in Cascades
Recent Geology paper: Time-evolving surface and subsurface signatures of Quaternary volcanism in the Cascades arc

Tuesday, October 27th - Online Zoom Presentation

Emilie Hooft, University of Oregon
Mapping the Magmatic Pathways Beneath Volcanoes from Newberry, Oregon to Santorini, Greece

What does the plumbing system beneath a volcano look like? Is it a big vat of magma? Or a long column? Or many layers of magma sills? It used to be that people thought there were big magma chambers under volcanoes, but it turns out they are often quite small and we do not yet know how magma plumbing systems are structured. In this talk, UO Earth Science Professor Emilie Hooft will describe how she uses seismic imaging to map the deep system of pathways that transport magma to the earth’s surface. Her cutting-edge research uses measurements from hundreds of seismic sensors to find differences in the rate at which sound passes through rocks, and is like making a CAT scan of a volcano. From a societal and hazards point of view, this gives us a better idea of what’s underground and how to predict what might happen when the volcano becomes restless. Additionally, this research helps scientists better understand how the earth functions, how big magma systems assemble themselves, and how they reset and regrow after major volcanic episodes.

Tuesday, September 22nd - 7:00PM Zoom Presentation

Marjorie Chan, University of Utah
Red Rocks from Earth to Mars

Mars is an exciting frontier for sedimentology, with opportunities to discover what might exist within its sedimentary layers and surface landforms. Through new technologies and instrumentation advances, we have the ability to scientifically explore the Red Planet at unprecedented scales. Comparative studies of red rocks on Earth have provided important clues for interpreting the geology on Mars. Small terrestrial concretions compared with “blueberries” found on the red planet, helped scientists understand the past environments on Mars. Other terrestrial examples of soft-sediment deformation and weathering show remarkable similarities to recent satellite and rover imagery from Mars. Studies from Earth are critical because terrestrial analogs help us interpret similar processes on Mars and give clues about where life might exist on the Red Planet.

This presentation will also include a perspective on how Earth science research will change in the future. Fields of sedimentary and planetary geology must leverage and employ the power of cyber-infrastructure, where data sharing and data management can open new science discoveries and relationships.
America's Geoheritage: Identifying, Developing, and Preserving America's Natural Legacy - Distinguished Speaker Series

Tuesday, May 26 - 7:00PM

Dr. Andrew Fountain, Portland State University
The History and Science of Glacier Change in Western US and a Peek into their Future

The Pacific Northwest is home to the most glaciers anywhere in the continental US. And we take glacier observations for granted, we know somebody is looking at them. But I got to wondering, when did glacier observations start and who started it? When did science discover glaciers here in the West? The history is surprising and the glaciers in Oregon played a major role. The cast of characters includes the famous and not so famous, and controversy brewed for more than a decade. And part of the controversy included, 'What is a glacier?'. Since their 'discovery' glaciers have been observed off and on since the start of the new century in 1900, mostly by amateur hiking clubs. These early observations have provided key data in understanding about how the glaciers have changed over time. While they are all retreating generally, there is one major exception, a new glacier, less than 50 years old. Sadly, however, their future is grim.

Dr. Andrew G. Fountain is a professor of Geology and Geography at Portland State University where he has conducted glacier research for the past 25 years. Prior to that he was a glaciologist with the US Geological Survey in Tacoma, WA and Denver, CO. His studies have taken him to Antarctica, Alaska, Arctic Sweden, and the western U.S. Greenland may be in his future. His studies on the glaciers of the American West can be viewed at www.glaciers.us

Tuesday, April 28 - Cancelled due to coronovirus

Seth Moran, Scientist-in-Charge, Cascade Volcano Observatory

Volcanoes in Our Backyard: Understanding and Mitigating Volcano Hazards in Central Oregon

Central Oregon is one of the few places on Earth where you can have a 10 (or 12, or 20) volcano day without having to leave your house. Volcanoes are everywhere on the landscape, including majestic stratovolcanoes like South Sister, caldera systems like Newberry Volcano, and volcanic fields with multiple cinder cones and lava flows like those at McKenzie Pass. In this presentation, Seth Moran will discuss what is known about volcanic hazards in Central Oregon, how those hazards are being mitigated through volcano monitoring and public outreach, and how lessons from the 2018 Kilauea eruption in Hawaii are being applied by the Cascades Volcano Observatory to improve eruption response planning in Central Oregon and elsewhere in the Pacific Northwest.

Tuesday, March 24 CANCELLED due to coronovirus

Andrea Balbas, Oregon State University
I Date Rocks: A Geochronology Love Story
Rocks are amazing in that they offer us a window into the past and tell stories that can be beyond human imagination. This allows us to understand Earth processes that we have not directly witnessed. A key to unraveling the possible cause and nature of such processes is an understanding of their timing and pacing. This is the power of geochronology. From the order of a stratigraphic sequence to the radiometric ages of lava flows, geologists have continued to invent and develop new ways for determining when something occurred in Earth’s past. For me, getting new ages from rocks is like taking a trip back in time and that is why I love it.

Tuesday, January 28

Ian Madin, Senior Scientist, Earthquake Hazard Geologist - Oregon Department of Geology and Mineral Industries

Three Newly Discovered Fault Systems in Oregon

DOGAMI Senior Scientist Ian Madin will discuss how using LiDAR (light detection and ranging) has led to newly discovered fault systems in Oregon: the Mt Hood, the White Branch of the McKenzie, and the John Day faults. Ian Madin has worked for DOGAMI since 1987, where he has served as the Seismic Hazard Geologist for the State of Oregon, Chief Scientist, and is now the Senior Scientist and Earthquake Hazard Geologist. During his time at DOGAMI he has supervised the agency's earthquake, landslide, geologic mapping, and LiDAR programs. He is also the author of the statewide geologic map Oregon: A Geologic History .

Tuesday, February 25

Josh Roering, University of Oregon

Mountains, Earthquakes, and Landslides: Using Lasers to Peer Behind Cascadia's Green Veil

University of Oregon earth sciences professor Josh Roering will describe how using LiDAR (light detection and ranging) has enabled scientists to bypass the typical obstacles of difficult terrain and dense closed-canopy forests to map the surface of the Cascadia landscapes in amazing detail. These new discoveries add to the dynamic geologic history of Northern California, Oregon and Washington, and have profound implications for geologic hazards, habitat conservation, and natural resource management.

Tuesday, November 26

William Orr, University of Oregon Professor Emeritus
Oregon's Checkered Past
University of Oregon Professor Emeritus William Orr will explore Oregon's spectacular fossil record and how it is closely linked to Oregon's volcanic history. Without an extensive record of volcanoes of every description, the state would never have developed the diverse and rich trove of fossil remains that it now boasts. William Orr is the author of several books on Oregon and Pacific Northwest geology, paleontology, water, and environmental history.
Oregon Geology
Geology of the Pacific Northwest
Oregon Fossils

An Environmental History of the Willamette Valley

Oregon Water: An Environmental History

Tuesday, September 24

Laird Thompson, University of Utah
Tectonic History of the Coos Bay Basin and its Relationship to Pacific Northwest ‘Siletzia’ Tectonics

Laird Thompson will explore the tectonic history of the Coos Bay Basin in southwestern Oregon and what it can tell us about the larger tectonic history of Oregon and the Pacific Northwest. The Coos Bay Basin overlies the southwestern margin of ‘Siletzia’, an accreted mass of marine basalt that forms the basement rock beneath western Oregon and Washington. Fault and fracture patterns within the Coos Bay Basin are visible in rock outcrops, lidar, gravity, and geologic maps. These patterns record four phases of tectonic deformation associated with the clockwise rotation of Oregon and the northward transport of Siletzia. This talk will build on material presented by Ray Wells in his visit to COGS in May of 2018.

Tuesday, October 22

Jim O'Connor, U.S. Geological Survey

The Other Flood: Ice-age Bonneville Flood on the Snake River

The Bonneville Flood was one of the largest floods on Earth. First discovered by G.K. Gilbert in the 1870s during his inspection of the outlet at Red Rock Pass, Idaho, it was rediscovered in the 1950s by Harold Malde and coworkers, leading to mapping and assessment of spectacular flood features along Marsh Creek, Portneuf River, and Snake River for over 1100 kilometers between the outlet and Lewiston, Idaho. The cataclysmic flood - from the rapid 115 meter drop of Lake Bonneville from the Bonneville level to the Provo level - was nearly 200 meters deep in places and flowed at a maximum rate of about 1 million cubic meters per second — about 100 times greater than any historical Snake River flood. Along its route the Bonneville Flood carved canyons and cataract complexes and built massive boulder bars. These flood features have been a rich source for understanding megaflood processes. Yet it still offers much more with new and developing techniques for hydrodynamic modeling and landscape analysis.

Tuesday, January 22

Anita Grunder, Oregon State University

The High Lava Plains of Oregon: Volcanic and Tectonic Connection between Yellowstone and the Cascades

The High Lava Plains is an enigmatic province between the hot-spot related Steens Basalts and the subduction-related Cascades. Dr. Grunder will explore the implications of the westward age progression of rhyolites and the effect of protracted magmatism on the composition of the volcanic rocks and the crust.

Links to two videos from Anita's presentation:

Cenozoic Volcanism in the Pacific Northwest - 55 million years to present

Magma evolution in an extentional setting—High Lava Plains

Cancelled due to Winter Storm

Tuesday, February 26

Josh Roering, University of Oregon

Tuesday, March 26

Allan Lerner, University of Oregon

Kīlauea's 2018 Fissure Eruption – Chronology, Processes, and Impacts of Kilauea's Largest Eruption in 200 Years

Kilauea Volcano is the youngest volcano in the Hawaiian island chain and one of the most active volcanoes on Earth. In spring 2018, volcanic activity at Kilauea took a dramatic turn, starting with a fissure eruption forming beneath a residential community and ultimately expanding into Kilauea's largest eruption in 200 years. This talk will provide a first-hand account of this historic eruption, which included thousands of earthquakes, major collapses of the summit caldera, and vast outpourings of lava that dramatically reshaped the southeast corner of Hawai'i.

Click HERE for a recent paper in Science by Allan and others on the 2018 rift eruption and summit collapse of the Kilauea volcano.

Click HERE for a video compilation from a helicopter overflight of Kīlauea Volcano's lower East Rift Zone on June 6, 2018, around 6:30 AM. The video shows the fissure 8 lava fountain feeding a channelized lava flow that travels northeast around the Kapoho cone, and then flows toward the south to enter the ocean at Kapoho Bay and Vacationland. The ocean entry has completely filled Kapoho Bay with lava, building a delta that extends 0.8 miles from shore.

Link to more videos from the Hawaii Volcano Observatory

Tuesday, April 23

Jeff Templeton, Western Oregon University
A NEW LOOK AT “OLD” TUFFS FROM NEWBERRY VOLCANO: EVIDENCE FOR DYNAMIC MAGMATIC PROCESSES AT A GEOLOGIC CROSSROADS IN CENTRAL OREGON

This talk will focus on ash-flow tuffs that shed light on the earliest
caldera-forming eruption at Newberry Volcano, which is located at the
west end of the High Lava Plains about 60 km east of the Cascades.
Geochemical data reveal a dynamic scenario involving injection of basalt
into a rhyolitic magma body and mixing to yield subsequently erupted
dacitic tuffs. Further, these data show that both Cascadia subduction
and the High Lava Plains influenced silicic magmatism at Newberry.

Tuesday, May 28

Hal Wershow, Central Oregon Community College

Holocene Glacial and Paleoclimate Reconstructions in the North Cascades, Washington

The glaciers of the North Cascades are a critical source of meltwater for surrounding ecosystems and human uses, especially during the otherwise dry Cascadian summers. However, the Holocene history of these glaciers is poorly understood, partly because most glacial records rely on preserved moraines and are therefore discontinuous. COCC geology instructor Hal Wershow will discuss how he reconstructed Holocene fluctuations of North Cascades glaciers from glaciolacustrine sediments (i.e., rock flour) in Lyman Lake, which drains the Lyman Glacier. These reconstructions give us new insights on Holocene glacial advances and retreats in the North Cascades.

Tuesday September 25

Assembling the Northwest: a roadside view of Oregon and Washington geology

Marli Miller, University of Oregon

With its spectacular mountain ranges, lush valleys and tumbling rivers, the Northwest landscape attracts nature lovers and travelers from around the world. But the rain-soaked coast range, snow-covered volcanoes and expansive high desert didn't appear overnight. They formed through a variety of geologic processes over millions of years. UO geologist and photographer Marli Miller will outline the geology of Oregon and Washington as seen along our federal and state highways. Beginning with the plate tectonic setting of the Pacific Northwest, she will describe the process of continental growth that forms the underlying but diverse "basement" of the region and is readily visible in the Coast Range, North Cascades, Okanogan, Klamath, and Blue Mountains. Following that, a photographic "roadtrip" up I-84 and Washington State Highway 14 in the Columbia Gorge will illustrate many of the younger features that make our landscape so unique.

Tuesday October 23

The Crooked River Caldera

Jason McClaughry, Oregon Department of Geology and Mineral Industries - Baker City Field Office

The Crooked River caldera is a 26-mile long, 17-mile wide volcanic depression formed through a series of super-volcanic eruptions between 29.7 and 27.5 million years ago. Eruptions from the Crooked River caldera deposited massive volumes (>140 cubic miles) of tuff and rhyolitic lavas, dikes, and domes. All of these volcanic features are now well exposed in the rock walls of Smith Rock State Park. Current research suggests that the Crooked River caldera records some of the oldest caldera-forming eruptions related to the passage of the Yellowstone volcanic hotspot from the coast of the Pacific Northwest to the modern Yellowstone caldera in Wyoming during the past 50 million years. Jason’s talk will focus on regional tectonic models and geochemistry linking the Crooked River caldera to the Yellowstone volcanic hotspot.

Tuesday November 27

Groundwater hydrology and groundwater-dependent ecosystems of central Oregon

Marshall Gannett, Research Hydrologist Emeritus

U.S Geological Survey

Groundwater is critical for humans and ecosystems in central Oregon. The volcanic geology of the Deschutes and upper Klamath Basins is widely known to host substantial regional aquifer systems that store and transmit large volumes of groundwater that supports year-round flow to many streams. What is less well known is that there are smaller-scale local aquifer systems that exist in the region as well, and that there are unique groundwater-depend ecosystems associated with these different scales of groundwater flow. Marshall Gannett will describe the groundwater hydrology of central Oregon, focusing on the upper Deschutes Basin, and discuss recent research aimed at understanding groundwater-dependent ecosystems and the sensitivity to climate change.

Spring 2018 Series

Tuesday March 27
Geothermal Exploration at Newberry Volcano
Bart Wills, U.S. Forest Service

Join the Central Oregon Geoscience Society and U.S. Forest Service geologist Bart Wills for a presentation on
the 40-‐year geothermal history at Newberry Volcano. The presentation will introduce the geology of Newberry
and discuss the formation of Newberry National Volcanic Monument, the most recent geothermal projects
at Newberry, and some of the difficulties these projects have encountered in producing geothermal power.

Tuesday April 24

Mount Hood: Confessions of an interesting Boring volcano

Adam Kent, Oregon State University

Mount Hood is an active subduction zone volcano, and is the site of the most recent volcanic eruption in Oregon. The volcano is also deeply embedded in the social and recreational fabric of the state of Oregon, but despite the iconic profile details of the inner workings of Mount Hood have been quite poorly known. Adam Kent will present new research that sheds light on past and future volcanic activity at Mount Hood, with a focus on the clues that can be extracted from studying the erupted rocks themselves.

Tuesday May 22

Oblique subduction, rotating crustal blocks, and the active tectonics of the Pacific Northwest
Ray Wells, Research Geologist Emeritus, U.S. Geological Survey

Oregon has been slowly rotating clockwise over geologic time. Coast Range basalt of the Siletz River Volcanics, about 50 million years in age, are rotated about 75°, whereas younger flows of the Columbia River Basalt (16-12 million years in age) exposed in the Coast Range are rotated about 20°. Rotations are largest along the coast and decrease inland. Northeast-directed subduction of the Juan de Fuca Plate beneath the continent drags the leading edge of Oregon northward, producing a clockwise shear in the continental plate. Ray Wells will present current understanding of active tectonics in the Pacific Northwest and the role that crustal rotation plays in the Cascade volcanoes and in shallow crustal faults in the Northwest urban corridor.

The COGS Visiting Scholar Program is an open invitation to scientists who are visiting central Oregon and would like to present their research to the community. Although we try to schedule these programs in advance, many of these opportunities come up on short notice based on the travel schedules of visiting scholars. All Visiting Scholar presentations will be posted as early as possible on the COGS website, and will be announced via email. Stay informed on our Visiting Scholar Program by becoming a member of COGS, or by signing up for our email list.

Thursday, June 25 - Online Zoom Presentation

William Orr, University of Oregon Professor Emeritus
Extinction: Using catastrophic events to construct the geologic timeline
Mass extinctions have been important markers in the geologic record since the geologic timescale was laid out over 200 years ago. University of Oregon Professor Emeritus William Orr will explore some of the largest mass extinction events in Earth's history, and our best estimates as to their cause. Recent ideas about the causes of extinction events will be presented, including volcanism and meteor impacts, as well as a look at some of the species that survived these catastrophes and how these events were used to construct the geologic timeline. William Orr is the author of several books on Oregon and Pacific Northwest geology, paleontology, water, and environmental history.
Oregon Geology
Geology of the Pacific Northwest
Oregon Fossils

An Environmental History of the Willamette Valley

Oregon Water: An Environmental History

Wesleyan University professor Johan Varekamp researches volcanic lakes around the world, including Paulina Lake and East Lake at Newberry Volcano. Join him for an overview of his research at Newberry, including volcanic venting of mercury and CO2 in East Lake, and hot spring activity at Paulina Lake as an analog for precambrian banded iron formations.

For more about Dr. Varekamp’s research: A tale of two lakes: the Newberry Volcano twin crater lakes, Oregon, USA

Wesleyan University student poster session at 6:00 PM

Haley Brumberger and Sabrina Koetter will have two posters about ostracods (tiny shrimp!) in Paulina Lake and how they preserve a record of lake water from the past.

Christina Cauley will have a poster on iron and silica rich sediments from Paulina Lake. Christina recently received a NASA Space Consortium grant for her research project “Chemistry and Biology of Giant Hydrothermal Mounds in Paulina Lake, Oregon.”

Fall 2021 Presentations

Past Presentations

Spring 2021 Series

Fall 2020 Series

Spring 2020 Series

Dr. Andrew Fountain, Portland State University
The History and Science of Glacier Change in Western US and a Peek into their Future

Fall 2019 Series

Tuesday April 24

Visiting Scholar Program

Fall 2021 Presentations

Past Presentations

Spring 2021 Series

Fall 2020 Series

Spring 2020 Series

Dr. Andrew Fountain, Portland State UniversityThe History and Science of Glacier Change in Western US and a Peek into their Future

Fall 2019 Series

Tuesday April 24

Visiting Scholar Program

Dr. Andrew Fountain, Portland State University
The History and Science of Glacier Change in Western US and a Peek into their Future