Columnar Joints: No, NOT in Colorado, But in Svartifoss, Devil's Tower, and Giant's Causeway

     Columnar joints are spectacular, often very long, hexagonal features found in igneous basalts (that's basalts not bathsalts!). Three particularly well-preserved examples are in Svartifoss, Iceland,

Devil's Tower, Wyoming, USA,

and the Giant's Causeway in far northeastern Ireland.

       [To clarify, there are columnar joints in Colorado; they are just not as spectacular as in those three places.]

        The mechanism for creating these six-sided features is seen here where 'C' represents the center of each hexagon:

        

      This two-minute geology video shows columnar jointing from the side and from the top in eastern Washington, USA. The accompanying one minute video shows what happened to a rock hammer atop those hexagonal features!

        The columnar joints in Iceland have inspired architecture for a local church. I still think our first PEOTS field trip ought to be to Iceland.

         More information about this hexagonal packing structure, including T- and Y- junctures, points toward a similarity to the optimally-packed honeycomb:

. . .and to mud cracks. . .

and to carbon rings in chemistry (benzene here):

and to . . .

      Isn't nature mesmerizing?! And more than she's cracked up to be!?

Steph

P.S.

Hmmm, Ethiopia is likely ahead of Iceland in my travel plans, but Iceland is a close second. . .