GSOC members can attend geological field trips led by professional geologists.

Field trips include both short local field trips and more adventurous multi-day overnight trips. Most trips require registering participants to be GSOC members. Registrants should be logged in before attempting to register.

GSOC is working hard to plan field trips for 2024. Please stay tuned for more information, which will be announced in the monthly email to members. The posted schedule on the home page will be revised and trip descriptions added below as plans are set.

Members should receive an email shortly after midnight on the eve of the registration kickoff date that will contain a registration link. Registration dates are shown on the field trip schedule on the home page of the website. Members should use the button on the email to register - please disregard the button shown on the website because our membership platform adds those automatically and they don’t go to the right page for signup. Each member will only be able to register themselves and one guest. If you want to go, register as soon as possible because our trips are popular and sell out quickly.

PRELIMINARY 2024 GSOC FIELD TRIP DESCRIPTIONS

Please note that trips are being planned and the detailed descriptions will be posted prior to registration. Our purpose in posting these preliminary descriptions is to give enough information for potential participants to decide whether to save the date and arrange any necessary lodging. See detailed trip descriptions below as they are posted.

Detroit Lake with Clark Niewendorp July 20

Did you know the cliffs on Highway 22 along the Detroit Reservoir, a nine-mile-long reservoir completed in 1953 by the U.S. Army Corp of Engineers, and the slopes and valleys to the south are part of a granodiorite stock (called the Detroit stock)? The Detroit stock is a mass of Late Miocene (~23 million years old) andesitic magma that didn’t reach the surface and is the largest pluton in the Western Cascades of Oregon, covering at least 6 square miles. It intruded into the older volcanic rocks of the Sardine Formation and was significant due to its association with nearby mineral deposits within those rocks.

GSOC is organizing a one-day field trip to examine the Detroit stock's geology and mineralization on the reservoir's south side. Then, our attention turns to aspects of the Middle and Late Miocene Sardine Formation exposed about four miles north of Detroit. One stop examines a major northeast-trending Hoover fault exposed along East Humbug Creek. An array of white zeolites, quartz, or both outline the offset fracture planes in the adjacent rocks—spectacular, and participants can collect some mineral specimens from a deposit nearby.

Yamhill County Wineries with Scott Burns Date TBA

Scott Burns is planning to lead a one-day terroir trip to Yamhill County, Oregon in late summer. This will be a bus tour of three wineries and their associated geology. The trip will be run with a budgeting model designed to keep fees to a minimum. So come along and enjoy the fruits of the harvest!

Iron Mountain with Clark Niewendorp September 7

GSOC (Geological Society of the Oregon Country) is organizing a half-day field trip to explore Iron Mountain’s Prosser Mine and geology. Participants will walk along the Oswego Iron Heritage Trail that once followed the path of a local narrow-gauge steam railroad that historically connected the mine to the Oswego furnace.

Willamette Eastbank Bike Geotour with Ian Madin September 22

Ride with us along the Eastbank from Portland's youngest rocks to its oldest.

This is a 3-hour, moderately-paced bike ride (9 miles) with an optional return by MAX. (A shorter 5 mile route, with return by MAX, is also available.) We will be starting from a location close to the Steel Bridge across from downtown Portland.

You will need to bring a bike, helmet, water, and your HOP Fastpass or other payment if you are planning to return on the MAX from Milwaukie.

Portland/Willamette Valley Landslides with Scott Burns September 28

Scott Burns is planning to lead a car caravan style trip visiting 8 to ten landslides in the Portland West Hills, including three of the most famous ones! This 3-hour tour will visit the sites, discussing the origin of the slides and steps taken to remediate them.