2023-11-11 Washington’s fossils—New book presentation

fossil diorama NPS

SATURDAY NOV. 11 – EVENT LIVE AT First Baptist Church – 1202 Lawrence St, Port Townsend – 4pm

or via ZOOM

Liz Nesbitt and David Williams (both associated with the Burke Museum) will present their new book on Washington Fossils. They will discuss the book and provide some background on their inspiration for the book, why they wrote it, and address some of the science, etc. For the second part, we’ll highlight some of the profiles in the book.

For the QGS, they will connect the geology with the fossils, and illustrate how/why we have certain fossils, such as those brought in on accreted terranes and where our oldest fossils are located..

On Sunday Nov. 12, they will present a different version for the PTMSC, which will focus on the marine organisms, such as the whales and methane seeps.

This is an early warning for what will be a fossiliferously wonderful weekend.  Watch this space for more details.  (posted Sept 23).

2023-10-14 Ophiolites—Subducted terrane exposed on Fidalgo Island

Fidalgo Ophiolite Revisited: A chaotic assemblage of ophiolitic blocks deposited in a matrix of mudstone, sandstone, and basalt flows overlain by deep-water turbidites derived from a volcanic arc – John S. Oldow, Whidbey Island

SATURDAY OCT. 14 – EVENT LIVE AT First Baptist Church – 1202 Lawrence St, Port Townsend – 4pm

or via ZOOM

The Lecture

It has long been thought that an intact ophiolite had accreted to North America and was preserved on Fidalgo Island in the San Juan Islands, just tens of miles north of Port Townsend.  (An ophiolite is a slab of oceanic crust and underlying mantle rock.)  These ophiolitic rocks are on spectacular display along the coast of Fidalgo Island, including in Deception Pass State Park, the most-visited state park in Washington.  This body of oceanic crust was interpreted to have subsequently been the site of an oceanic island arc, a chain of volcanoes, with parts of the island arc’s volcanic rock also accreted.  Mount Erie, the highest point on Fidalgo Island, is underlain by a body of granite that represents a magma chamber beneath one of the volcanoes.  It is easy to see why Fidalgo Island has long been a major attraction for people interested in exploring complex geology.

Recently, Dr. John Oldow and his Ph.D. student David Katapody reexamined and reinterpreted the geology of Fidalgo Island and adjacent islands.  Here blocks of various parts of the subduction complex and volcanic arc were deposited as sedimentary mélange composed of debris flows and rock falls carried into a basin containing mudstone, sandstone, and basalt flows.  The deep basin was ultimately filled and overlapped by deep marine clastic rocks derived exclusively from the adjacent island-arc complex.  The mélange and overlap succession were subsequently subducted to high pressure – low temperature conditions before being returned to the surface and imbricated along the North American Cordillera.  Their work rewrites the geology of the area and calls for revising how the accreted terranes of the area have been mapped and named.  The work of Oldow and Katapody is a fresh, eye-opening look at the rocks of the San Juan Islands and how they formed.

The Speaker

John Oldow received his BS degree in geology from the University of Washington in 1972 and his Ph.D. in geology from Northwestern University in 1978. He taught geological sciences with a specialty in structure and tectonics for 40 years: at Rice University for 17 years, at the University of Idaho for 13, years and at the University of Texas Dallas for 10 years before he retired from academia in 2018. He returned home to the Pacific Northwest and lives on northern Whidbey Island. He is still active in research projects in the western Great Basin, northern Alaska and northwestern Canada, and the San Juan Islands of Washington State. He continues to consult for mineral and petroleum exploration companies and holds a position as a Research Associate at Western Washington University.

The Location

This hour-long lecture will be presented in-person at the First Baptist Church at 1202 Lawrence St. in uptown Port Townsend starting at 4 pm.  In addition, the presentation will be recorded on Zoom for real-time and later viewing.

2023-07-08 Walk to the Rocks Field Trip

Geology of Tamanowas Rock and Peregrines Rock, Chimacum, WA

Click here for the registration form.

Tamanowas Rock aerial image

On Saturday, July 8, 2023, several QGS geologists will lead 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 that will be emailed as a pdf to all attendees in early July.

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 will describe 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 orientated to the north, perhaps in Canada.

The field trip costs $20, is limited to 40 persons and requires advance registration (by snail mail). Registration for the field trip will start June 14th (Wednesday) and close on June 28th (Wednesday). Those who register after we have reached our limit may request to be placed on a wait list. The trip will run no matter the weather conditions, since some participants will have travelled from a distance.  Click here for the registration form.