Argon geochronology maps of North America

Helpful background:

• Geochronology
• K/Ar dating

Making these maps was relatively simple.

I took the data from two massive, online government databases:

• USGS national geochronological database
• Canadian geochronology knowledgebase

After a bit of work (and absolutely no quality control)  I made a list of 21,451 K/Ar and Ar/Ar ages, referenced against latitude and longitude. These were plotted on a map of North America, and color-coded by geological age.

Here's the complete North America picture, with bins chosen based on the timeline of North American orogenies.

 And a close-up of the Western U.S., with bins chosen to emphasize the chronology of the last 200 million years.

  

And finally, a histogram of the ages, plotted with a logarithmic y-axis. Cyclicity anyone?