EDITOR’S NOTE: The date of the presentation has been corrected.
PORT TOWNSEND — Geologist Jim Aldrich will present a picture of geologic hot spots through the lens of U.S. national parks at 4 p.m. Saturday, Feb. 24.
Admission will be free to the lecture at Quimper Unitarian Universalist Fellowship, 2333 San Juan Ave., but donations will be appreciated.
“Hot” features of four national parks — American Samoa (South Pacific), Haleakala (Maui), Hawaii Volcanoes (Island of Hawaii), and Yellowstone (Wyoming) — result from mantle-plume eruptions at Earth’s surface.
This illustrated presentation will address basics of mantle-plume processes shown by the Hawaii hot spot and geologic features associated with the National Park of American Samoa and Yellowstone National Park.
Emphasis will be on Yellowstone’s hot spot, which has a long and varied eruption history that began on the sea floor before it was overridden by the North American continental plate, organizers said.
The Yellowstone hot spot is likely the source of the huge volumes of basaltic volcanism that formed a large oceanic plateau that accreted to North America in the Paleocene and Eocene and created Tamanowas Rock.
This large igneous province extends from coastal Oregon to southern Vancouver Island. During the Cenozoic Era, beginning 65.5 million years ago, this hot spot fueled three massive caldera eruptions that distributed volcanic ash around the world.
Today, the hot spot beneath Yellowstone National Park manifests as numerous geothermal features.
A Sequim resident, Aldrich earned geology degrees at Dickinson College and Lehigh University and completed his doctorate at University of New Mexico in 1972.
He has held teaching positions at Allegheny College and North Carolina State University, where he taught a wide variety of geology courses and a field camp.
At Los Alamos National Laboratory (LANL), Aldrich conducted geologic studies in southwestern U.S. and Central America and environmental assessments and restoration work in and around the laboratory.
Although he retired from LANL in 2004, he enjoys geology so much that he spends a good deal of his “free time” studying the structural development of the Olympic Mountains.
Aldrich is on the advisory board of the Jefferson Land Trust’s Geology Group, as well as being a former board member of Friends of the Field, and current board member of the North Olympic Land Trust.
