Location: Deschutes Brewery - Mountain Room 
                 901 SW Simpson Ave, Bend, Or 97702 

General Agenda:

     5:30 PM Join us for food & beverages
     7:00 PM Presentation


No regularly scheduled presentations over the summer – please join us 
for field trips!

Tuesday, September 24
    To Be Announced

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, November 26
Title: TBA

Past Presentations


Spring 2019 Series

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
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, 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

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.

Fall 2018 Series

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.                  

Visiting Scholar Program

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.