Wheeler Shale


The Wheeler Shale is a Cambrian fossil locality world-famous
for prolific agnostid and Elrathia kingii trilobite remains
and represents a Konzentrat-Lagerstätte. Varied soft bodied organisms are locally preserved, a fauna and preservation style normally associated with the more famous Burgess Shale. As such, the Wheeler Shale also represents a Konservat-Lagerstätten.
Together with the Marjum Formation and lower Weeks Formation, the Wheeler Shale forms of limestone and shale exposed in one of the thickest, most fossiliferous and best exposed sequences of Middle Cambrian rocks in North America.
At the type locality of Wheeler Amphitheater, House Range, Millard County, western Utah, the Wheeler Shale consists of a heterogeneous succession of highly calcareous shale, shaley limestone, mudstone and thin, flaggy limestone. The Wheeler Formation extends into the Drum Mountains, northwest of the House Range where similar fossils and preservation are found.

Taphonomy and sedimentology

Detailed work recognises a number of ~10 m thick lagerstätten sequences in the formation, each of which formed at a sea-level highstand in deep water. The lagerstätte were deposited by turbidities and mudslides onto an oxygenated sea floor.
The productive layers comprise mud and clay particles, with a tiny fraction of wind-blown quartz.

Stratigraphy

The Wheeler Shale spans the Ptychagnostus atavus and uppermost-Middle Cambrian Bolaspidella trilobite zones .

Fauna

Incomplete list of the fauna of the Wheeler Shale:

Protista