Geoscience Challenge, Feb 2013–By Dr. C

Woman sitting on rock columns

Here is Dr. C’s second Geoscience Challenge, moved from his facebook page.  Geoscience Challenge Feb 2013–This month’s challenge is to figure out why the rock in the picture has such a geometrical form and where this picture was taken. (Hint: Volcano’s can be in most amazing places, can’t they!) Answers in a month!— with Mary Colson.

Mary Colson I look a lot younger then, well at least a lot younger than the rocks! :0). February 17, 2013 at 7:12pm
  • Laurie Sand Is that columnar basalt at the north shore of lake superior that I see??? February 17, 2013 at 7:52pm
  • Jessie Rock Oh what fun. I love this idea Russ. Is it columnar basalt in the pacific northwest? The vegetation looks lush. These columns form from the contraction of thick lava as it cools. Here’s a question: Why are the columns always vertical? February 21, 2013 at 10:37am
  • Christine Kimmelman Columnar basalt are amazing, formed that way from cooling lava, the certain minerals in the lava maybe take that shape when cooled slowly. I don’t think columnar basalt are always vertical but these ones are, could be from the lava flow placement? I think it’s Washington state like Jessie Rock said about the lush vegetation. This is fun. Can’t wait to find out.  February 21, 2013 at 11:23am
  • Jane Dahl Feickert Apparently I don’t have a geological clue….:)February 21, 2013 at 4:19pm
  • Russ Colson Jane: 3 people like the Pacific NW, you being one! Answers in a week or so.  February 21, 2013 at 4:42pm
  • Ann Dulhanty being from Canadian shield country, every fractured rock I see looks like glacial influence, but that doesn’t seem to be the trend in the conversation, presumably by people who know better than me  February 21, 2013 at 8:01pm ·
  • Jessie Rock Look at those trees. I think Laurie Sand is right. Could that be the” North Shore”? Are these rocks associated with the the failed rift?  February 21, 2013 at 11:32pm
  • Russ Colson Well. Sorry for taking so long to get back to this! End of February to middle of May is my “hang on by the fingernails” time of the year. And the Answer IS…..Sure enough it’s ancient volcanic basalt from the North Shore of Lake Superior! Gooseberry Falls SP to be exact. An amazing place for volcanos isn’t it? Volcanos all gone, lava still here. The basalt columns form when lava cools and shrinks, causing the rock to fracture in roughly hexagonal columns. Jessie, do you want to comment on your questions–Why are they vertical?  April 6, 2013 at 5:14pm
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One thought on “Geoscience Challenge, Feb 2013–By Dr. C

  1. This is great, even though I’m a year late. We have outcrops of this near Jarbidge, NV along the southern extent of the Snake River Plains. Columnar jointing.

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