Carbonatites are strange igneous rocks made up mostly ofcarbonates – common minerals like calcite, calcium carbonate. Igneous rocksthat solidify from molten magma usually are high-temperature rocks containinglots of silicon which results in lots of quartz, feldspars, micas, andferro-magnesian minerals in rocks like granite and basalt. Carbonatitesc…

As near as I can tell in the original daily series in 2014,I never addressed the topic of turbidity currents and their sedimentaryproduct, turbidites. But they account for the distribution of vast quantitiesof sediment on continental shelves and slopes and elsewhere. You know what turbid water is: water with a lot of suspendedsediment, usually fine…

This episode is about some of the interestingconnections that arise in science. We’ll start with me and my first professional job as amineralogist analyzing kidney stones. My mineralogy professor at IndianaUniversity, Carl Beck, died unexpectedly, and his wife asked me as his onlygrad student to carry on his business performing analysis of kidney s…

Today we’re going back about 280 millionyears, to what is now Uruguay in South America. 280 million years ago puts us in the early part of thePermian Period. Gondwana, the huge southern continent, was in the process ofcolliding with North America and Eurasia to form the supercontinent of Pangaea.South America, Africa, Antarctica, India, and Austral…

Today we’re going to the Mountains of theMoon – but not those on the moon itself. We’re going to central Africa. There isn’t really a mountain range specifically named theMountains of the Moon. The ancients, from Egyptians to Greeks, imagined orheard rumor of a mountain range in east-central Africa that was the source ofthe river Nile. In the 18th …

Today’s episode focuses on one of thosewonderful jargon words geologists love to use: Ophiolites. It’s not a contrived term like cactolith nor some reallyobscure mineral like pararammelsbergite. Ophiolites are actually really importantto our understanding of the concept of plate tectonics and how the earth worksdynamically. The word goes back to 18…

In today's episode we’re going to space.Specifically, Mars. You didn’t really think that earth science is reallylimited to the earth, did you? Our topic today will be the Valles Marineris. The Valles Marineris is a longseries of canyons east of Olympus Mons, the largest mountain in the solarsystem. These canyons are about 4,000 km long, 200 km wide…

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 incommon is hot or at least warm water, so they occur in geothermal areasespecially, but they also are found in the Arctic. They range in si…

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 seriesfrom 2014 that are about Cretaceous and Cenozoic vertebrates. I’ve left the references to specific dates in the podcast sothat you can, if you want, go to the specific blog post that ha…

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 original seriesfrom 2014 that are about Triassic and Jurassic vertebrates. As usual, I’ve left the r…

Vanadium is a metal, and by far its greatest use is in steelalloys, where tiny amounts of vanadium improve steel’s hardness, toughness, andwear resistance, especially at extreme temperatures. As I reported in my bookWhat Things Are Made Of, more than 650 tons of vanadium was alloyed with ironto make the steel in the Alaska Pipeline, and there’s no …

You may have seen some of the spectacular images of theearth in southern Algeria, curves and colors like some Picasso in the oppositeof his cubist period. If you haven’t, check out the one from NASA, below. The ovals and swirls, with their concentric bands, areimmediately obvious to a geologist as patterns of folds, but not just linearfolds like ma…

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 theintimate connection between geology and beer. Beer is mostly water, and water chemistry has everything todo with beer styles. And water chemistry itself depends mostly on the kinds ofrocks through which the water flows. You know about har…