History of the Earth

History of the Earth episodes:

• 04.30.2018

  Episode 397 Carbonatites

  Carbonatites are strange igneous rocks made up mostly of carbonates – common minerals like calcite, calcium carbonate. Igneous rocks that solidify from molten magma usually are high-temperature rocks containing lots of silicon which results in lots of quartz, feldspars, micas,...

  
• 04.17.2018

  Episode 396 Turbidity currents

  As near as I can tell in the original daily series in 2014, I never addressed the topic of turbidity currents and their sedimentary product, turbidites. But they account for the distribution of vast quantities of sediment on continental shelves...

  
• 04.10.2018

  Episode 395 Connections

  This episode is about some of the interesting connections that arise in science. We’ll start with me and my first professional job as a mineralogist analyzing kidney stones. My mineralogy professor at Indiana University, Carl Beck, died unexpectedly, and his...

  
• 04.03.2018

  Episode 394 The Mangrullo Formation of Uruguay

  Today we’re going back about 280 million years, to what is now Uruguay in South America. 280 million years ago puts us in the early part of the Permian Period. Gondwana, the huge southern continent, was in the process of...

  
• 03.27.2018

  Episode 393 The Mountains of the Moon

  Today we’re going to the Mountains of the Moon – but not those on the moon itself. We’re going to central Africa. There isn’t really a mountain range specifically named the Mountains of the Moon. The ancients, from Egyptians to...

  
• 03.20.2018

  Episode 392 Ophiolites

  Today’s episode focuses on one of those wonderful jargon words geologists love to use: Ophiolites. It’s not a contrived term like cactolith nor some really obscure mineral like pararammelsbergite. Ophiolites are actually really important to our understanding of the concept...

  
• 03.13.2018

  Episode 391 Valles Marineris

  In today's episode we’re going to space. Specifically, Mars. You didn’t really think that earth science is really limited to the earth, did you? Our topic today will be the Valles Marineris. The Valles Marineris is a long series of...

  
• 03.06.2018

  Episode 390 Mud Volcanoes

  As the name implies, mud volcanoes are eruptions of mud – not molten rock as in igneous volcanoes.  They’re found all around the world, amounting to about a thousand in total number known. The one thing they have in common...

  
• 03.04.2018

  Cretaceous and Cenozoic Vertebrates compilation

  Smilodon and dire wolves (drawing by Robert Horsfall, 1913) Running time, 1 hour. File size, 69 megabytes. This is an assembly of the episodes in the original series from 2014 that are about Cretaceous and Cenozoic vertebrates. I’ve left the...

  
• 03.04.2018

  Triassic and Jurassic Vertebrates compilation

  Morganucodon, a possible early mammal from the Late Triassic. Length about four inches.Drawing by FunkMonk (Michael B. H.) used under Creative Commons license.  Running time, 1 hour. File size, 68 megabytes. This is an assembly of the episodes in the...

  
• 02.27.2018

  Episode 389 Vanadium

  Vanadium is a metal, and by far its greatest use is in steel alloys, where tiny amounts of vanadium improve steel’s hardness, toughness, and wear resistance, especially at extreme temperatures. As I reported in my book What Things Are Made...

  
• 02.20.2018

  Episode 388 Folds in Algeria

  You may have seen some of the spectacular images of the earth in southern Algeria, curves and colors like some Picasso in the opposite of his cubist period. If you haven’t, check out the one from NASA, below.  The ovals...

  
• 02.15.2018

  Episode 385 The Magnetic Field Anomaly

  Most of my career was in analyzing features of the earth’s gravity and magnetic fields, to infer geologic structures for oil exploration. But that doesn’t mean I really understand the whole earth’s fields – and for some aspects of it,...

  
• 02.13.2018

  Episode 387 Geology of Beer

  It isn’t true that all geologists drink beer. But many do, and I’m one of them. Today I’m going to talk about the intimate connection between geology and beer. Beer is mostly water, and water chemistry has everything to do...

  
• 02.11.2018

  Paleozoic Vertebrates compilation

  Ganoid fish from an old textbook (public domain) Running time, 1 hour. File size, 70 megabytes. This is an assembly of the 15 episodes in the original series from 2014 that are about Paleozoic vertebrates. I’ve left the references to...

  
• 02.06.2018

  Episode 386 Dynamic Topography

  What is dynamic topography? Well, it depends on who you ask. Dynamic topography is similar to other terms, like uplift, that have been used in so many different ways that you really have to look at the document you’re reading...

  
• 02.01.2018

  Episode 384 Kyanite

  Today’s topic is three minerals with the same chemical formula: Kyanite, Andalusite, and Sillimanite.  How can three things with the exact same chemical formula, Al2SiO5, be different minerals? Many of you probably recall that besides a distinct chemical composition, a...

  
• 01.16.2018

  Episode 383 Himalayas, Catskills, and more

  For today’s episode of the podcast I’m introducing you to Dr. Petr Yakovlev, a friend and geologist here in Butte at the Montana Bureau of Mines and Geology. Petr will be doing occasional guest episodes to give you all a...

  
• 01.09.2018

  Episode 382 The Riversleigh Lagerstätte

  Today’s Episode takes us to Australia, the home of the Riversleigh Lagerstätte. Lagerstätten, you may recall, are fossil assemblages that typically have extraordinary diversity as well as extraordinary preservation. The Riversleigh Lagerstätte fits that definition well, containing fossils of 15-...

  
• 01.02.2018

  Episode 381 Zealandia

  Today for episode 381, we’re going to Zealandia. No, it’s not a quirky TV show modeled after Portlandia. It’s the 7th largest continent on earth. We’re not talking continents in the geographic sense, really large land masses like Africa and...

  
• 12.26.2017

  Episode 380 Makoshika State Park, Montana

  The badlands at Makoshika State Park are in Montana, and so am I, but Montana’s big. The park is just outside of Glendive, almost at the eastern border of the state. It took me and my friend about seven hours...

  
• 12.19.2017

  Episode 379 Gondwana Glaciation

  Today’s episode, number 379, is about glaciers in what is now the Sahara Desert, and we’re going back 340 million years, to the Mississippian or Early Carboniferous Period of the Paleozoic Era. In the original daily episodes of this podcast...

  
• 12.11.2017

  Episode 378: Pegmatites

  If you’ve listened to this series for any length of time, you know that geologists, like most scientists, are fond of jargon. They use specialized words as shortcuts for particular meanings, like ‘gabbro,’ which is easier to say than “a...

  
• 12.04.2017

  Episode 377: The Tepuis

  Today’s topic for Episode 377, the Tepuis of South America, was suggested long ago by a listener. Photo of Mt. Roraima by Jeff Johnson, used under  Creative Commons Attribution-Share Alike 3.0 Unported license.Transcript: The Tepuis are huge, high-standing plateaus isolated from their surroundings...

  
• 11.27.2017

  Episode 376: US Mineral Dependency

    Welcome to the History of the Earth podcast where we discuss all things geological. I’m your host, geologist Dick Gibson. There’s been a long hiatus in my production of this podcast, and I hope to rectify that with some new...

  
• 01.08.2016

  Episode 375: Garnets

  Garnet is the birthstone for January, but there really isn’t a single mineral named ‘garnet.’ It’s a group of at least 15 minerals of differing chemistry, but only six are common. They are three aluminosilicates combined with iron, magnesium, or...

  
• 11.28.2015

  The Cenozoic Episodes

  Running time 3 hours We are up to the Cenozoic Era in the monthly episodes. This one combines the 31 episodes from December 2014, covering the Cenozoic, into one episode, and it completes the packaging of each month of episodes...

  
• 11.24.2015

  Episode 374. Twins

  This week, our topic is twins. Twinned crystals. When two, or sometimes more, crystals of the same mineral share volumes or surfaces within the crystal lattice, they grow together in interesting ways. One common kind of twin is essentially a...

  
• 11.24.2015

  The Cretaceous Episodes

  Running time 2 hours 30 minutes We are up to the Cretaceous Period of the Mesozoic Era in the monthly episodes. This one combines the 30 episodes from November 2014, covering the Cretaceous, into one episode. As usual for this...

  
• 09.28.2015

  The Jurassic Episodes

  Running time 2 hours 5 minutes We are up to the Jurassic Period of the Mesozoic Era in the monthly episodes. This one combines the 31 episodes from October 2014, covering the Jurassic, into one episode. As usual, I’ve left...

  
• 08.22.2015

  The Triassic Episodes

  Running time 1 hour 45 minutes Shonisaurus from the Triassic of Nevada. Maximum length, 49 feet. Drawing by Nobu Tamura http://spinops.blogspot.com used under Creative Commons license.We are up to the Triassic Period of the Mesozoic Era in the monthly episodes. This...

  
• 08.15.2015

  Episode 373. A walk to Branham Lakes

  Upper Branham LakeToday’s episode will be a little different from what you are used to. I’m going to try to give some of the story of the Precambrian here in southwestern Montana, but I’ll do it in the context of...

  
• 07.29.2015

  Episode 372 Satellite-derived gravity

  Welcome to the History of the Earth, which has now evolved into a general podcast covering all things geological. I’m your host, geologist Dick Gibson. Today I’m going to talk a bit about one of my specialties, interpretation of gravity...

  
• 07.24.2015

  The Permian Episodes

  Running time 2 hours We are up to the Permian Period of the Paleozoic Era in the monthly episodes. This one combines the 31 episodes from August 2014, covering the Permian, into one two-hour episode. As usual, I’ve left the...

  
• 07.12.2015

  The Pennsylvanian Episodes

  Running time 1 hour 45 minutes This episode is the seventh monthly package that combines the daily episodes for July 2014, covering the Pennsylvanian Period of the Paleozoic Era. As with the Mississippian, I apologize for not getting this assemblage...

  
• 07.07.2015

  The Mississippian Episodes

  Running time 1 hour 30 minutes This episode is the sixth monthly package that combines the daily episodes for June 2014, covering the Mississippian Period of the Paleozoic Era. I apologize for not getting this assemblage done on time –...

  
• 05.08.2015

  Episode 371: Listener Questions

  Today for Episode number 371 I’m going to try to address some of the questions I've received on the blog or through the podcast. A fair number of these were addressed in comments here on the blog, and I usually...

  
• 04.30.2015

  The Devonian Episodes

  Running time 2 hours 20 minutes This episode is the fifth monthly package that combines the daily episodes for May 2014, covering the Devonian Period of the Paleozoic Era. As usual, I’ve left the references to specific dates in the...

  
• 04.01.2015

  The Silurian Episodes

  Running time 2 hours This episode is the fourth monthly package in the History of the Earth Calendar. It combines the daily episodes for April 2014, covering the Silurian Period of the Paleozoic Era. As usual, I've left the references...

  
• 03.23.2015

  Episode 370: Pseudomorphs

  Malachite pseudomorph after cuprite showing octagon and dodecahedron faces. From Chessy, France. Specimen is just over 1 cm in maximum dimension. Photo by Richard I. Gibson.Today for Mineral Monday my special guest is Kyle Eastman, mineral collector and geologist, here...

  
• 03.12.2015

  The Mineral Episodes

  This episode is a package containing all the previous episodes of the podcast related to minerals and mineral deposits. There are 16 of them, and the running time is about an hour and thirty minutes. Thanks very much for your...

  
• 02.25.2015

  The Ordovician Episodes

  Running time 2 hours 15 minutes This episode is the third monthly package of the History of the Earth calendar. It combines the daily episodes for March 2014, covering the Ordovician Period of the Paleozoic Era. You’ll find that I’ve...

  
• 02.14.2015

  Episode 369: Gallium

  On my What Things Are Made of blog, by far the most popular post is one on the element gallium. I don’t know why this is so, unless there are a lot of middle schools assigning homework on gallium. So...

  
• 02.01.2015

  The Cambrian Episodes

  Running time 2 hours 10 minutes For 2014, the podcast consisted of daily productions averaging about 5 minutes each. The individual episodes for each month are now being assembled into packages for each month, representing various spans of time in...

  
• 01.27.2015

  Episode 368: Alaska, 1898

  Today’s episode is from my book, What Things Are Made Of and the chapter that includes gold. THE LAST GREAT GOLD RUSH began in August 1896, when prospector George Washington Carmack and his two Indian companions, Skookum Jim and Tagish...

  
• 01.20.2015

  Episode 367 – Kidney stones

  Today I want to talk about some of the youngest minerals on earth – kidney stones. Some might argue whether these should be considered minerals at all, since part of the definition of a mineral is other than man-made, but...

  
• 01.16.2015

  The Precambrian - the daily episodes from 2014 combined

  For 2014, the podcast consisted of daily productions averaging about 5 minutes each. The individual episodes for each month are now being assembled into packages for each month, representing various spans of time in the history of the earth. This...

  
• 12.31.2014

  December 31. The 6th Extinction

  So we’ve made it to the end of our geological year, covering 4.6 billion years of geologic time. 366 episodes, close to 180,000 words and a total of about 25 or 30 hours of programs. I hope you’ve enjoyed it!...

  
• 12.30.2014

  December 30. Modern Plate Tectonics

  Through the year, we’ve talked about events that broke apart and combined the various tectonic plates on the earth, but today, as we’ve almost reached the present, I wanted to just summarize the way things are today.  First, I know...