30 December 2014
Skolithos in Gog quartzite, on the trail to Helen Lake
Posted by Callan Bentley
Some boulders seen on the trail to Helen Lake sported lovely sets of Skolithos trace fossils. Here are two boulders, with the perspective on the tubular paleo-vertical Skolithos burrows being “map view”:
Another boulder, in the middle of the trail, showed them in a fine cross-sectional view:
(click to enlarge substantially)
It also included some interesting “ribbed” vertical traces that I didn’t recognize as familiar:
…Diplocraterion, perhaps? Seems too “linear” and not curved enough for that, though. They are about 3 or 4 times as thick as a “typical” Skolithos, which I would say is 3-4 mm.
Callan Bentley is Associate Professor of Geology at Piedmont Virginia Community College in Charlottesville, Virginia. He is a Fellow of the Geological Society of America. For his work on this blog, the National Association of Geoscience Teachers recognized him with the James Shea Award. He has also won the Outstanding Faculty Award from the State Council on Higher Education in Virginia, and the Biggs Award for Excellence in Geoscience Teaching from the Geoscience Education Division of the Geological Society of America. In previous years, Callan served as a contributing editor at EARTH magazine, President of the Geological Society of Washington and President the Geo2YC division of NAGT.
Skolithos are more likely Arenicolites – paired tubes in the first two surface views of the boulders. I think you’re right about the Diplocraterion in the bottom couple of pics.
Once again, you show that geologists have all the fun.
I saw some skolithos in river boulders outside of Lake Louise. You can find the “ribbed” (annulated) skolithos in the Zabriskie Quartzite in Death Valley as well. Nice pictures!