For anyone who might be interested, today's USGS United States earthquake map has a very beautiful delineation of the "Utah Hinge Zone" as we used to call it. You can see a line of small quakes running from the SW to NE in Utah. This marks a region where the old paleozoic continent ended. Fabulous geological area.

Just thought that I'd point out the aesthetics of our planet!

good wishes to all, PennyB