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Wednesday, September 25, 2013

Paperblog & Tafoni Report

Tafoni -- curious pockets in rock.
Emma contacted me last week with an invitation to join Paperblog:
“Having come across your blog, In the Company of Plants and Rocks, I wanted to get in touch to introduce you to Paperblog. We are a new media sharing platform for blog writers and we would like you to be a part of it.”
So far I’ve learned that this is a blog aggregator, with some 20,000 blogs organized into “magazines”.  Plants and Rocks would be included in the Outdoor one.  It appears that Paperblog makes money through advertising, and participants get the hope of increased readership.  Anyone can submit a blog for consideration.

Do you paperblog?  If so, any information or advice would be appreciated!
What does Paperblog have to do with tafoni?  Nothing really.  Participation requires this validation article, and for interest I'm including photos from a recent trip to the eastern edge of the Colorado Plateau, near Grand Junction, Colorado.
“I confirm the subscription of this blog to the Paperblog service under the username hollis”
Whenever I hike in McInnis Canyons I become enchanted by the many holes and pockets in the rock, called tafoni.  They're whimsical in shape and arrangement, and maybe-just-maybe one will lead to a secret path!
How do tafoni come to be?  There are many hypotheses.  In fact, there’s an entire website devoted to what we know, think and speculate about tafoni.
In the Entrada sandstone in McInnis Canyons, tafoni often occur in lines along bedding planes (above and below; click on photos for better views).  Perhaps some sediment layers included small rocks as well as sand.  When exposed by erosion perhaps the rocks fell out, leaving little holes that expanded with time.  Perhaps.
We found other kinds of tafoni.  In one area, many little pockets covered brown sandstone boulders, possibly part of the Summerville or Morrison Formations -- a diverse collection of strata above the Entrada.
Sometimes one surface would be covered with small tafoni while orthogonal to the pock-marked side was cross-bedding.  Hmmm ... how did this come to be?
Tafoni often set my mind to wandering.
Some tafoni showed signs of habitation, by various critters:
Bird's nest.
Black dog seeking shade.
Happy geo-geek.
More tafoni can be found in reports from 2012:  McInnis Canyons, Rabbit Valley, the Honeycombs, and the Central California Coast.

2 comments:

  1. Hi Hollis--we've found holes on horizontal surfaces in Utah that were made or at least grew larger when little pebbles moved around enough (wind, water?) to wear the holes bigger. For example, there were holes with pebbles in them in which the shape of the pebble fit the shape of the perimeter of the hole. I'm not explaining it very well, but you probably know what I mean. Doesn't explain the vertical tafoni though, or some of the other phenomena you describe here...

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    Replies
    1. Hi Ken :) I do know what you mean ... I've seen those too, also fun to contemplate. and thanks for reading!

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