Diamonds have been revered as precious stones for over 2000 years, yet they are composed simply of carbon, one of the most common elements on Earth. Their rarity arises from the fact that they form at extreme pressures deep in the Earth’s mantle and then are brought rapidly to the surface in CO2-rich explosive eruptions. No such eruptions have occurred in human history, but we know they occur only in the interiors of continents, where they produce narrow vertical ‘kimberlite pipes’ that are mined in Africa, Russia, and, more recently, Canada. Tiny diamonds with a completely different origin have been found in meteorites, and some of these appear to predate the formation of our solar system. Nowadays, diamonds can also be grown artificially; these synthetic crystals are widely used in industry and, increasingly, in jewelry. For geologists, diamonds are invaluable tools for understanding the Earth’s interior. They are used to make tiny “anvils” that allow us to conduct high-pressure laboratory experiments that replicate conditions deep inside the Earth, and they commonly contain minute inclusions of other minerals that are our only actual samples of mantle materials from depths as great as ~400 km (250 miles). In this talk Jeff will provide how and where diamonds form, offer a brief summary of how we search for them, describe their history as gemstones, and detail what they tell us about our planet’s deep interior.
This IN-PERSON ONLY lecture will start at 4 PM on Saturday, February 15, 2025. This event is free and open to the public. (Donations gratefully welcome at the door.) The lecture will be recorded and posted shortly after the presentation, as are all our events since 2020.
ABOUT THE SPEAKER:
Jeff Tepper was on faculty of the Geology Department at the University of Puget Sound from 2001-2021 and has been emeritus since then. He earned his PhD from UW, where he studied the origins of granite in the North Cascades. At UPS he taught classes in mineralogy, petrology, geochemistry, GIS, and geomythology. Most of his research projects focus on the magmatic and tectonic history of the Pacific Northwest (including Tomanowas Rock) or on the geochemistry of water and sediment from Tacoma-area lakes. Visit Jeff’s website for more information: https://www.jeffreytepper.com/.
Cold War Science and Engineering Today Reveals Greenland’s Fragility in an Overheating Climate
Greenland, a remote arctic island, holds in its ice enough water to raise sea level over six meters (20 feet). That is enough to flood every major coastal city and displace up to half a billion people. Yet, until recently we knew very little about the past comings and goings of this massive ice sheet. Through the lens of climate science, environmental history, and the stories of people who studied Greenland over the past century, Paul will use the past to look into a warming future. He will fill the talk with photographs, movies, and recordings from the 1930s onward, review the science done by the international team that he led, and tell stories from his book, When the Ice is Gone. A key finding of Paul and his fellow researchers is that the Greenland ice sheet appears to have melted away completely during a previous interglacial warm climate, which suggests it could do so again if today’s warmer climate continues. The talk will be accessible to anyone with an interest in science and history.
A small preview to Paul’s lecture may be found at:
Paul Bierman, environmental science professor at the University of Vermont, develops methods to date ice and rocks. He has published in Science and Nature, with the findings covered by CNN, USA Today, and the Weather Channel. Paul is a 1993 graduate of the University of Washington (Seattle) where he earned his MS and doctorate in Geoscience after a BA at Williams College.
Paul lives in Burlington, Vermont and his passions include telling stories and solving the mysteries of our planet. He is equally at home in a dusty archive and a cleanroom without a speck of dust. A history and geoscience researcher by training and a teacher for over four decades, Paul looks at our planet with wonder and curiosity. His career has taken him to searing deserts and frigid ice sheets. Throughout, he has focused his energies on understanding the link between our Earth and human societies – what today we call, sustainability. He enjoys education at all levels and is the author of three textbooks and a book for the general public, When the Ice is Gone.
The Quimper Geological Society (QGS) hosts lectures on Saturdays. Many of us enjoy (and rely on) the social aspect of the get-togethers at Port Townsend’s First Baptist Church and conversations before and after the lectures. The day of the lecture is filled with a flurry of activities and it is difficult to get to our members’ more “personal geologic” questions. So, QGS is extending our geologic events to provide more opportunities for our Quimper community to socialize and ask questions.
QGS is happy to help you identify a particular rock. We ask that you bring questions and rock samples to the pub the day after the lecture, where we can spend more time examining your specimens and answering your queries.
At the first meeting of “Meet Your Local Geologists”, on September 16, 2024, the day after Darrel Cowan’s lecture, several local geologists met at the Port Townsend Pour House to discuss a number of geological processes. Some interesting rocks got examined. A good time was had by all! Some folks hoped that QGS would continue to meet and discuss more geology…
So now, QGS will hold an event we will call “Meet Your Local Geologists”. We plan to meet the Sunday after our Saturday hosted lecture. These gatherings will probably take place after every other lecture. Here is information about our first such event.
SPECIFICS:
“Meet Your Local Geologist”
When: November 17, 2024
Time: 3-5 PM
Location: Pour House (2231 Washington St, Port Townsend)
Please check the QGS website frequently for the next occurrence… quimpergeology.org.
Please check the QGS website frequently for the next occurrence…