I have only barely been able to hide my fascination with Akadama…and am seeking people with first hand knowledge of the areas where it is mined and produced. Akadama is a bit of a geological unicorn in terms of its origins and development, which is one reason why it appears to come from but a few localities in Japan. If anyone has some insight to these production areas, the physical setting and proximity or distribution of the various source areas, I would be tremendously thankful for that information.
Some have seen the website I created to document my research into its origin and genesis, with the idea that if we can understand how it was formed, we might find similar earth materials here in the northwest. If you haven’t, here it is: Hunting Oregon Akadama
So Asymmetry friends, can you help me refine the mental model for the origins of this material? Do the Akadama quarry sites occupy low lying terraces along rivers in the Kanuma province only, as I propose in the website? Do the sites occur in other locales or at higher elevations? Any help ground truthing these questions will be greatly appreciated.