Category: National geology

2023-10-14 John Oldow – Subducted terrane exposed on Fidalgo Island

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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

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 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.

2023-05-13 Vince Matthews — Global Scramble for Natural Resources

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Vince Matthews, former director of the Colorado Geological Survey and now a consulting geologist in Wisconsin, spoke on the Global Scramble for Natural Resources. This was a ZOOM broadcast Saturday, May 13, 2023.

The Lecture

During the 1990s, the world’s most populous nations—China and India–were unleashed from Communist and Socialist regimes, respectively. The first decade of the 21st Century saw China’s GDP grow at more than 10 percent per year and India’s at 7-9 percent. Both are drastically increasing their use of all natural resources. Although they have resources of their own, they are insufficient to meet their internal demand.

Because the world’s mineral and energy resources are being strained to supply these exploding economies, the price of nearly every natural-resource commodity dramatically escalated beginning in 2003. Not only did the price of commodities increase, but the competition to simply obtain a share of these natural resources became intense. From cement, to petroleum, to fertilizer, to strategic metals; the scramble for a piece of the worldwide commodities pie is in a state the world has never known. The U.S. is being, and will be, significantly affected by this new world disorder.

As America looks increasingly to alternative energy sources, we face an increase in imports to achieve our goals.  Many of the current alternative energy technologies use a variety of imported mineral commodities, especially “rare earths.” The country’s increasing vulnerabilities to foreign sources of strategic mineral commodities were slow to be recognized.

The Speaker

Dr. Vince Matthews received B.S. and M.S. degrees in geology from the University of Georgia and a Ph.D. from the University of California, Santa Cruz. He was awarded “Outstanding Alumnus” recognition from both institutions. His career includes holding executive positions with four natural resource companies and teaching at eight institutions of higher education, two of them tenured positions.

About ten years ago Vince retired as Director of the Colorado Geological Survey. In retirement, he has served as Interim Executive Director of the National Mining Hall of Fame and Museum, served on the Special Scientific Committee on the Health Effects of Unconventional Oil and Gas Development in the Appalachian Basin, presented Zoom talks on a variety of topics to geological societies and universities, led field trips in the Rocky Mountains, completed the manuscript for a book entitled, Land of Ice: Jaunts into Colorado’s Glacial Landscape, and was recruited to teach “Earth Resources and Sustainability” at the University of Wisconsin-Eau Claire last fall semester.

2022-12-10 Marcia Bjornerud – Timefulness

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The Lecture

Developing and calibrating the geologic timescale — reconstructing Earth’s past from the raw rock record — is one of humanity’s greatest, but least appreciated, intellectual achievements.   But as a society, we are time illiterate, lacking a sense for the durations of the chapters in Earth’s history, the rates of change during previous intervals of climate instability, and the intrinsic timescales of ‘natural capital’ like groundwater systems.  This matters because environmental wrongs, social conflicts and existential malaise are all rooted in a distorted sense of humanity’s place in the history of the natural world.  Thinking like a geologist can simultaneously ground us and elevate us. Paradoxically, this Earth-bound, very physical science can yield transcendent insights.

Timefulness was longlisted for the 2019 PEN/E.O. Wilson Prize for Literary Science Writing and was a finalist for the 2018 the Phi Beta Kappa Award in Science, and the LA Times Book Prize in Science & Technology.

The Speaker
Marcia Bjornerud, Professor of Geosciences at Lawrence University in Wisconsin, is a structural geologist whose research focuses on the physics of earthquakes and mountain building. She combines field-based studies of bedrock geology with quantitative models of rock mechanics. She has done research in high arctic Norway (Svalbard) and Canada (Ellesmere Island), as well as mainland Norway, Italy, New Zealand, and the Lake Superior region.  Bjornerud is a Fellow of the Geological Society of America and has been a Fulbright Senior Scholar at the University of Oslo, Norway and University of Otago, New Zealand. A contributing writer to The New Yorker, Wired, the Wall Street Journal and the Los Angeles Times, she is also the author of several other books for popular audiences — Reading the Rocks: The Autobiography of the Earth and Geopedia: A Brief Compendium of Geologic Curiosities.