Unknown burrow and bioturbation in a polished section

[BobZombie]

Provenance is a problem.. sample is a cobble of late Wisconsin glacial origin, derived from a Lake Ontario shoreline drumlin environment. It most likely originated in the drumlin sediments. Existing studies place the majority of the sedimentary till clast sources as locally derived late Ordovician, early Silurian mud/silt/sandstones and limestones (minor) deposited in an epicontinental sea environment.. via macrostrat, undifferentiated Medina Group and Queenston Formation. Oswego Sandstone is also a contributor to area till. And there are plenty of Canada and Adirondack gneiss clasts and others to found indicating transport from these areas.

 

Stone is siliclastic. Thinking paralitic clastic marginal marine, perhaps tidal, based on rip up clasts at bottom, heterolithic bedding in the center area, cut chanel in L stone (center, upper third). Polished section on right. Scale in mm. What made the burrow and bioturbation above it? I welcome your input.

[westcoast]

Simple answer is there is no way to tell what made the burrow. Very nice specimen however and good sedimentological detective work.

[BobZombie]

1 hour ago, westcoast said:

Simple answer is there is no way to tell what made the burrow. Very nice specimen however and good sedimentological detective work.

So it's not a typical, documented burrow type? Love to hear the long answer..

[westcoast]

Well in general it is difficult to assign a maker to most trace fossils, footprints are a notable exception. There are so many creatures that make similar burrows wirhout any tell-tale diagnostic features that unless you have the maker preserved in the burrow you can't say for sure what made it. Add to that your lack of certainty of the age of the specimen just increases the unknowns. Molluscs or arthropods are possibly the most likely potential makers.

[BobZombie]

1 hour ago, westcoast said:

Well in general it is difficult to assign a maker to most trace fossils, footprints are a notable exception. There are so many creatures that make similar burrows wirhout any tell-tale diagnostic features that unless you have the maker preserved in the burrow you can't say for sure what made it. Add to that your lack of certainty of the age of the specimen just increases the unknowns. Molluscs or arthropods are possibly the most likely potential makers.

I've got several dozen more samples to cut and a supply that gets renewed each spring due to lakeside drumlin bluff erosion. Hopefully I can run across something more diagnostic. Are you aquainted with Lothar Vallon's online ichno database? He flow charts specifiics to possible solutions. Example, my sample is: burrow.. vertical to sub-vertical..  unbranched.. conical or club-shaped.. passive fill.. without lining/mantle Unfortunately the two results for my sample seem to reflect neither the flow chart nor my sample.. lol.

 

https://www.ichnopolis.dk/html/ichnotaxa-database.html