Mark Wilson June 5th, 2013
NOTO, SICILY, ITALY–The first stop on our International Bryozoology Association field trip today was a newly-opened quarry near Cugni di Rio in the dry southeastern countryside of Sicily, a view of which is above. New quarries are always interesting to geologists — a new view of the Earth’s bones.
This is a portion of the quarry wall with the inevitable volcaniclastic unit of ash and marine sediments shown as the greenish layered unit above and below limestones dated as Tortonian (Upper Miocene). On top of the ash you can see what look like tubes sticking out of the brownish layer of sediment.
When that brownish layer is exposed as the underside of the bedding plane, it looks like this. These branching features are infilled tunnels made by marine shrimp. The walls of the tubes are ornamented by pellets placed there by the shrimp in their frenetic activity. Combining these pellets with the branching style we can place this trace fossil in the venerable ichnogenus Ophiomorpha.
This is a closer view showing the branched galleries and maybe a bit of the pitted surface showing where the pellets were attached. These tunnels are completely filled, so we refer to this preservation as full relief.
I know, I know, I should be recording the bryozoans from this stop, but they were far from photogenic!