24 July 2012
Tool casts from the Sulphur Mountain Formation of the Spray River Group, Banff
Posted by Callan Bentley
Yesterday I showed you salt casts; today I’ll share a different kind of cast: the infillings of small scorings in the sediment made by tumbling pebbles or sticks or other “tools,”tumbling down a current. These small gouges were later infilled from above by a younger deposit of sediment (frequently coarser in grain size). You’re looking at the bottom of a bed here:
These are strata of the Sulphur Mountain Formation, part of the Triassic Spray River Group in Banff National Park. The outcrop is next to the parking lot for Bow Falls in the Banff townsite, where the Bow River cuts through Rundle Mountain to make Tunnel Mountain.
These are the best tool marks I’ve seen in a long time. They reminded me of the excellent flute casts I saw in 2008 on the Pennsylvania Turnpike.
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.
My name is Hongyuan Zhang, comes from China University of Geosciences in Beijing. Can I use the flute casts photos during my field teaching and in the future published book? I will credit you in the field teaching book.
Sure – go for it.