What moves the continents, creates mountains, swallows up the sea floor, makes volcanoes erupt, triggers earthquakes, and imprints ancient climates into the rocks? Oliver Strimpel, a former astrophysicist and museum director asks leading researchers to divulge what they have discovered and how they did it.
To learn more about the series, and see images that support the podcasts, go to geologybites.com.
Bob Hazen on the Evolution of Minerals
New rock types emerge during the history of the Earth. For example, the silica-rich felsic rocks such as granite that characterize continental crust, accumulated during the course of Earth history. Granite only forms in certain specific tectonic settings, such as above subduction zones and when lower crustal rocks melt in mountain belts. But what about the minerals themselves? Have they been around since the Earth formed, or did they too only appear on the scene later as a result of some geological process?
The question of how and when the minerals evolved is a relatively new subject, and was, and continues to be, pioneered by this episode's guest. Bob Hazen is Senior Staff Scientist at the Earth and Planets Laboratory of the Carnegie Institution for Science and Professor of Earth Sciences at George Mason University. At a Christmas party in 2006, a well-known biophysicist asked him the question: “Were there clay minerals in the Archean?” Apparently, nobody had given this much thought prior to 2006. The topic quickly became the focus of his research, rapidly blossoming into a whole new branch of mineralogy.
Matt Jackson on the Heterogeneity of the Mantle
Matt Jackson is a Professor of Earth Science at the University of California, Santa Barbara. He probes the chemical composition of the mantle by analyzing trace elements and isotopes in hot-spot lavas from around the world. In the podcast, he describes the intriguing heterogeneity among the hot-spots of the so-called “hot-spot highway” in the western Pacific. The heterogeneity there, as well as on larger spatial scales is challenging our ideas about the motions of the mantle over the billions of years of Earth history.
Carmie Garzione on Reconstructing Land Elevation Over Geological Time
Throughout geological history, various points on the Earth’s surface have been lifted up to great elevations and worn down into low, flat-lying regions. Determining surface elevation histories is difficult because rocks that were once on the surface are usually eroded away or buried. Furthermore, most rock-forming processes are not directly affected by elevation. But it turns out that we can overcome these challenges, as Carmie Garzione explains in the podcast.
Carmie Garzione is Dean of the College of Science at the University of Arizona. She has managed to pin down the history of elevation changes by analyzing stable isotopes of carbon and oxygen in carbonate rocks. She describes how the method works, and presents her findings for the Tibetan plateau and the Andes. They show pulses of very rapid (geologically speaking) uplift. What might this be telling us about what has been going on in the lower crust and upper mantle in these regions?
Chuck DeMets on High-Resolution Plate Motions
The magnetic stripes frozen into the sea floor as it forms at mid-ocean ridges record the Earth’s magnetic field at the time of formation. Reversals in the Earth’s magnetic field define the edges of these stripes, in effect time-stamping the sea floor position.
Chuck DeMets is Emeritus Professor of Geoscience at the University of Wisconsin, Madison. He studies the magnetic anomalies in seafloor rocks to reconstruct plate motions at a temporal resolution five times better than has been done hitherto. This has revealed unexpected speed-ups and slow-downs in plate motions that provide juicy puzzles for geodynamicists. In the podcast he focuses on the detailed motions of the Indian plate that show, among other things, that its northward movement actually sped up for a period after the collision with Eurasia before it settled down to a steady slower speed.
Go to geologybites.com for podcast illustrations and to learn more about Geology Bites.
Mike Searle on Ophiolite
As the name implies, oceanic lithosphere underlies the oceans of the world. Except when they are ophiolites, when oceanic lithosphere is thrust on top of a continental margin. Are ophiolites a special kind of oceanic lithosphere? Or are there peculiar tectonic circumstances that emplace denser oceanic rocks on top of lighter continental ones? Mike Searle addresses these questions, and reveals the sequence of events that created the world's most extensive and best-preserved ophiolite - the Semail ophiolite in Oman.
Mike Searle is Emeritus Professor of Earth Sciences at the University of Oxford and at the Camborne School of Mines in Cornwall.
For podcast illustrations, go to geologybites.com.
Mackenzie Day on Dunes
Some of the most extensive sandstone deposits in the world were deposited by wind. How do such aeolian rocks differ from water or ice-deposited rocks? And what do they reveal about the environments in which they formed? In the podcast she describes the dunes we see in the geological record on Earth, as well as on Mars and on a comet, and explains what we've learned from them.
Mackenzie Day is an Assistant Professor in the Department of Earth, Planetary, & Space Sciences at the University of California Los Angeles. She is an expert in aeolian processes. In the podcast she describes the dunes we see in the geological record on Earth, as well as on Mars and on a comet and explains how they formed.
Go to geologybites.com for podcast illustrations and to learn more about the series.
Concise interviews with geology researchers. Excellent audio quality. Has a great companion website as well.
Best geology podcast format
I have spent the last 1.5 years learning about geology by listening to the entirety of 3 different geology podcast series, reading books, and watching online lectures. In my opinion this podcast nailed the format better than others. Each episode is full of information that is edited flow and be coherent. Awesome work, thank you!!
Eloquent and informative stories about geology
This is just about one of the best podcasts in my library. Mr. Strimpel and his interviewees provide a way to understand rocks in our world in a way that utilizes the experience and knowledge of the top geologist in the world. He is able to unpack complicated theories and research so that the novice can understand how volcanoes work and other geologic phenomena. I could listen to this podcast indefinitely. What a treasure!