Walk to the Rocks:  Geology of Tamanowas  Rock and Peregrine’s Rock, Chimacum, WA

The Trip—Lead by the QGS Rockstars

On Friday, July 8, 2022, the QGS Rockstars (four of our geologists) will lead a 4-mile, 4-hour hike (11AM—3PM) 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 hike can be vigorous, steep, and rough in parts and is tailored to agile citizen scientists who are already knowledgeable about geologic principles and vocabulary. Subjects to be discussed include the glacial history of the Quimper Peninsula, specifically Chimacum Valley, glacial erratics on the Peninsula, and the geology of the underlying Eocene volcanic rocks. Tamanowas Rock is a special part of this story and a sacred place of the S’Kallum people.  Tamanowas Rock is the remnant of an explosive volcano that erupted about 43 million years ago.  It is comprised of Adakite, an unusual type of lava that forms under anomalously high temperatures when a subducted oceanic plate starts to melt.

Conversely, Peregrine is a glacial erratic named by Erik Nagel, a participant in our Great Erratic Challenge two years ago. It currently is the largest erratic documented on the Quimper Peninsula. The Rockstars are currently preparing a concise, illustrated guidebook (pdf), which will be emailed to all attendees in early July.  The field trip is limited to 50 hikers and requires advance registration (by snail mail) and a $15 fee (by check).  Deadline for RECEIPT of your form and check is Friday, July 1.  Those who register but exceed our limit may request to be placed on a wait list. The trip will run no matter the weather conditions, since the Rockstars will have travelled long and far to lead this trip.  Click on the the registration button below to download the required form.