Bimodal Volcanoes: The Injection Volcanism Model

Bimodal volcanoes have a different history than other kinds of volcanic features as they share both mafic and silica-based material. This presentation will show how this happens through what Dr. Paul Hammond called the injection volcanism model. The presentation will show how the different amount of SiO2 and MaFe effects the mineral composition and the volcanic products and explosiveness.

Register for the Zoom event here. Note: Zoom will open at 7:00 to allow pre-show attendee visitation. The program will begin at 7:30 PM.

Speaker Bio:

Steve Carlson has lived in the Pacific Northwest his entire life and has been teaching since he was 25 years old. He has been an adjunct professor at Portland State University since 1977, teaching Minerology and Igneous Petrology. He also taught in the Mature Learning program at both Clark College and The Discovery Center in Earth Science, was a Science Guide for Cruise West and Road Scholars, and a Director of Science Education at Portland Public Schools. He was the primary investigator as well as an author/editor on several NSF projects related to research on Mt. St. Helens. He received the Deans award for innovative instructions.

Now meeting at Dick's Primal Kitchen, 4905 S.E. Woodstock Blvd, Portland. 

DO YOU HAVE A ROCK YOU WANT TO BRING TO SHOW-&-TELL?

Feel free to bring an interesting rock, mineral, or fossil to bring to show-and-tell! No scientific knowledge is required, but it's always fun to discuss:

WHERE DID YOU FIND IT? e.g. "my grandmother's yard" or "Wyoming" or "Clackamette Park" or even GPS coordinates on a map.

WHAT DOES IT MEAN TO YOU? Our group uses a scientific lens to look at the world, but the natural world has a lot of meanings to different people, so this might include:

• "This is the quartz crystal that started my love of geology at age 5!"
  
• "This cobble has special meaning to my fellow tribal members."
  
• "This 3 billion year-old fossil inspires awe every time I hold it!"
  
• "This is one of my field samples from my research last summer."

Register at https://www.taborfriends.org/urban-nature-series

Free 1 hour geology walk led by GSOC Communications Director Paul Edison-Lahm.

Once a month at 2:00 p.m., starting at the Mt. Tabor Visitors Center. (Check the Tabor Friends website above for date and registration.)  

Sponsored by Friends of Mt. Tabor/Urban Nature Series.  

Join us on September 28th to hear special guest Nick Zentner talk about the evidence of multiple glaciations in the Oregon Cascades, and Alyssa Smith returns to give us the Geology News & Research.

Nick is an award-winning educator who has been teaching Geology at Central Washington University since 1992. Through his You Tube livestreams, including his wildly popular A - Z series, the PBS 'Nick on the Rocks' videos, his 'Pop-up Geology' field sessions, and more, he has built a faithful and appreciative following of geology enthusiasts around the world.

Note: Zoom will open at 6:30 to allow participants to visit, the program will begin at 7:00.

Zoom link here.

The Pliocene to Pleistocene Goat Rocks Volcanic Cluster: Development of a major magma locus in the southern Washington Cascade Range

Near and within the Goat Rocks Wilderness in Washington state, between Mount Rainier and Mount Adams, lie the remnants of several volcanoes that were active between ~3.6 million years ago and ~60 thousand years ago. Gutted by recent glaciation, the volcanic stratigraphy is laid bare for exploration by geologists and hikers alike. From an early explosive rhyolite eruption to mafic shield volcanoes to composite volcanoes that erupted some of the world’s longest andesite lava flows, these volcanoes spanned a wide range of magma compositions and eruption styles. Dr. Kellie Wall and collaborators have used field observations, geochronology, and chemical compositions of the volcanic rocks to reconstruct the eruptive timeline and investigate magma sources, storage conditions, and pre-eruptive magmatic processes—building toward a 4D view of how a major volcanic locus builds, evolves, and ends. Kellie will share recent updates to her PhD work and will highlight recent and ongoing projects by student collaborators at Central Washington University.

Register for Zoom event here. Note: Zoom will open at 7:00 to allow pre-show attendee visitation. The program will begin at 7:30 PM.

Speaker Bio:

Dr. Kellie Wall is a Mapping Geologist for the Oregon Department of Geology and Mineral Industries (DOGAMI). Previously, Kellie worked as a postdoctoral researcher at the USGS Cascades Volcano Observatory. She earned her PhD at Oregon State University.