Snake Creek Formation

Transcription

Hello Young People. Columnar Basalt. Hiking today near Othello, Washington. Look at these columns. They're perfect! And 50 feet high. These columns are found in a rock called basalt which is a lava flow rock. We have them all over eastern Washington, but we can also find columns like this - Devil's Tower in Wyoming, Giant's Causeway in Ireland, we've even found columnar basalt on Mars. Here in eastern Washington, the Ice Age floods came barreling through this country thousands of years ago, ripping up a lot of bedrock, and exposing these columns. To figure out why the columns form, how 'bout we actually climb to the top of these columns, walk around up there, and see if we can't figure things out. C'mon, let's get up there. Each of these is a column. We're up on top of them now. These cracks are 50 feet deep. And these cracks, with this beautiful pattern, are found all through nature. You go to a drying mud puddle after a thunderstorm - and you see cracks like this. You go to the Arctic - and you see permafrost with cracks in these shapes. These lavas cooled 10.5 million years ago. When the lava came in at 2,000 degrees Fahrenheit and probably cooled over the course of a century - 100 years of cooling - these cracks got established back then as the lava was cooling. Contracting. Surfaces shrinking. And the net result. Columnar Basalt. Near Othello, Washington.