2024-06-21 Discovery Bay Tsunami Evidence Field Trip

Examine Discovery Bay’s Past Tsunami Record Using Two Contrasting Evidential Methods

There are at least two salient features of Pacific Northwest history:  an extremely active geologic past, coupled with a region inhabited by indigenous peoples since “time immemorial”.

These two features share common ground at Discovery Bay on the Quimper Peninsula of Washington State. Many tsunamis have occurred at this bay over at least the past 3000 years, during which time the area was concurrently inhabited by indigenous peoples.

This field trip examines the geologic and anthropological evidence of the occurrence of multiple tsunamis in Discovery Bay. Our field trip leaders, Dr. Carrie Garrison-Leavy (geologist) and Dr. Alexandra Peck (anthropologist), are active researchers in their respective fields, which are specific to this topic. They lead us through an examination of the possible link between tidal marsh tsunami sedimentation and indigenous oral histories as contrasting evidential methods of recording tsunami history.

About the Speakers

Dr. Carrie Garrison-Laney is a Coastal Hazards Specialist at Washington Sea Grant and a liaison to the NOAA Center for Tsunami Research. A focus of Carrie’s research has been the age and distribution of paleo-tsunami deposits with lessons learned from historical events. She earned her PhD from the University of Washington.

Dr. Alexandra Peck is professor and Audain Chair in Historical Indigenous Art at the University of British Columbia. Trained in archaeology, her research explores pre-colonial Native life, cultural change, and social interactions on the Olympic Peninsula. With extensive academic publications, she is also co-editor of Archaeology in Washington.

Carrie suggests for the wetland portion of the trip:

Wetland participants must come equipped with at least knee-high boots since the tsunami sediments are exposed in a tidal marsh. This will be messy but fun!!!!

 

2023-07 Tamanowas and Peregrine Rocks field guide

For the Tamanowas and Peregrine Rocks field trip, use the link below to download the guidebook.  Please print a copy for your use on the trip: the figures and photographs will be particularly useful.

For location and historical info about the Jefferson county site –>

For 2022 field trip report –>

Click here:  Tamanowas Rock guidebook

If you have technical or logistical questions, contact webmaster@quimpergeology.org

2023-07-08 Walk to the Rocks Field Trip

Geology of Tamanowas Rock and Peregrines Rock, Chimacum, WA

Tamanowas Rock aerial image

On Saturday, July 8, 2023, several QGS geologists led a 4-mile, 4-hour hike (12 PM—4 PM) from HJ Carroll County Park near Chimacum to the Tamanowas Rock Sanctuary, then up on top of Tamanowas Ridge to see Peregrine’s Rock. The elevation gain on the walk is about 300 ft. This is a repeat of our 2022 trip and includes a 13-page illustrated guidebook.

The upper part of the trail is moderately difficult but slow paced and the hike is tailored to agile citizen scientists who are knowledgeable about basic geologic principles and vocabulary. Subjects to be discussed include the glacial history of the Quimper Peninsula and Chimacum Valley, glacial erratics on the peninsula, and the geology of the underlying Eocene volcanic rock that forms Tamanowas Rock, which is a special part of this story and a sacred place of the S’Kallum people. Allie Taylor of the Jamestown S’Kallum Tribe described the history of the site and its importance to the Tribe.

Tamanowas Rock is a remnant of deposits from an explosive volcano that stood near here about 43 million years ago; it is comprised of adakite, an uncommon type of rock that forms when subducted oceanic plate melts. Aadakite requires unusually hot conditions in the mantle, which in this case occurred during establishment of the Cascades.

Conversely, Peregrine’s Rock is a glacial erratic named by Erik Nagle, a participant in our 2020 Great Erratic Challenge. It currently is the largest erratic documented on the Quimper Peninsula. We believe that it is greenstone (metamorphosed basalt) that originated to the north, perhaps in Canada.