The 366 daily episodes in 2014 were chronological snapshots of earth history, beginning with the Precambrian in January and on to the Cenozoic in December. You can find them all in the index in the right sidebar. In 2015, the daily episodes for each month were assembled into monthly packages (link in index at right), and a few new episodes were posted from 2015-18. Beginning in May 2019, I'm adding short entries to the blog (not as podcast episodes, at least not for now, sorry!) mostly taken from the Facebook Page posts. Thanks for your interest!

Wednesday, May 15, 2019


Thule was the far north in Greek and Roman literature, often identified with Scandinavia. Thursday was named after Thor, the Norse god of thunder. Whether these pink minerals are orthorhombic thulite or monoclinic clinothulite would take analysis that I haven’t done, but either way they contain trivalent manganese to give the pink color. 

The white mineral that contains them is scapolite, specifically meionite (I HAVE had an x-ray analysis of it), a different calcium-aluminum silicate. The outcrop, a couple miles up the Delmoe Road from the Pipestone exit, is mostly scapolite, in a zone that is the continuation of the boundary between the Butte and Rader Creek Plutons of the Boulder Batholith.

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