Quimper Geological Society
Many citizens will be practicing for the Big One on October 19th. Here is shake map and shake scale models resulting from a 7.4 event on the South Whidbey Island Fault. Full article with description of projected damages is found at https://earthweb.ess.washington.edu/gomberg/ShakeMap/ShakeMaps.html
Co-authors Elizabeth Nesbitt and David B. Williams discussed their new book, Spirit Whales and Sloth Tales: Fossils of Washington State. They provided background on what inspired them to write their book on fossils in Washington state, why they chose the fossils they did, and some of the new science that has allowed paleontologists to tease out the 500-million-year long story of life in this region. They connected the geology with fossils and illustrated how/why we have certain fossils, such as those brought in on accreted terranes and where our oldest fossils are located.
On Sunday, November 12th they presented a complementary version of this talk for the Port Townsend Marine Science Center at the Fort Worden Chapel. It focused on the marine organisms, such as the whales, and faunas of methane seeps.
David Williams is an author, naturalist, and tour guide whose award-winning book, Homewaters: A Human and Natural History of Puget Sound is a deep exploration of the stories of this beautiful waterway. He is also the author of Too High and Too Steep: Reshaping Seattle’s Topography, Stories in Stone: Travels Through Urban Geology, as well as Seattle Walks: Discovering History and Nature in the City. Williams is a Curatorial Associate at the Burke Museum and writes a free weekly newsletter, the Street Smart Naturalist (https://streetsmartnaturalist.substack.com/ – by clicking the “No thanks” you may access the previous newsletters). More information about David’s books may be found at www.geologywriter.com
Liz Nesbitt is Curator Emerita of invertebrate paleontology at the Burke Museum for Natural History and Culture, as well as, associate professor of Earth Science at the University of Washington. Her distinguished scientific contributions to the marine paleontology of the Pacific Northwest have earned many awards and honors, including having a tiny fossil snail and a fossil whale (Maiabalaena nesbittae) named for her, .
She is currently working with Burke colleagues on measuring the health of Puget Sound waters using microfauna in bottom sediments.
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 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.
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.