Saturday, December 23, 2006

Lines in the Rock--Saturday Photo Hunt

Checkerboard Mesa
Checkerboard Mesa, Zion National Park, Utah
This is what the sign told me about the cracks in the rock:
"The horizontal lines, commonly called crossbedding, represent layers of wind-blown sand that built up into sand dunes. These dunes were then buried, and the sand grains glued together by calcite and iron oxide to form sandstone. . . . The vertical lines are less common. They are actually shallow cracks that result from stress and erosion on the rock surface. These cracks are probably caused by expansion and contraction, temperature changes, wetting/drying, or a combination of these processes.

8 comments:

Anonymous said...

What a great picture for today's theme!

Merry Christmas!

Nicki said...

That's just beautiful! Thanks for the explanation too :)

srp said...

Great lines for the theme. I will have to direct my daughter here. She is a geology major and loves rocks of all types, weather, volcanoes and such.
Have a very happy Christmas!
Mine is up too.

Attila the Mom said...

That almost looks like--dinosaur skin! Great picture!

p said...

great composition, very nice!

Heather in Beautiful BC said...

Wonderful picture! Oooh, it does look like dinosaur skin Attila :)

Barb said...

Very interesting! (It looks like MY skin lol)

Sunflower said...

Great picutre for the LINES!

Sunflower