23 August 2011

My best flutes

Posted by Callan Bentley

Fellow geobloggers Brian and Eric have been getting all flutey on us lately, so I figure it’s a good time to show my best photo of flute casts:

As the annotated copy suggests, this was taken on the side of the Pennsylvania Turnpike back in March 2008, when four Honors students and I drove up to Buffalo for a northeastern section GSA meeting.

The strata are probably Devonian in age, redbeds deposited by streams draining the newly-upthrust Acadian highlands to the east, and then carrying the resulting sediment to the west towards an epeiric sea. Maybe they’re the Hampshire Formation; That’s what they look like at first glance. The flute casts are on the bottom of a sandstone bed that was deposited atop a red shale bed (into which the flutes were scoured). Stratigraphically, you’re looking “up” at the bottom of that bed, although its modern position (thanks to the subsequent Alleghanian Orogeny) is vertical, so really you’re looking sideways.

I held the quarter to the vertical bed with a wad of chewing gum, by the way.