The Wheeler Shale (named by Charles Walcott ) is a Cambrian ( c. 507 Ma ) fossil locality world-famous for prolific agnostid and Elrathia kingii trilobite remains (even though many areas are barren of fossils) and represents a Konzentrat-Lagerstätte . Varied soft bodied organisms are locally preserved, a fauna (including Naraoia , Wiwaxia and Hallucigenia ) and preservation style ( carbonaceous film ) normally associated with the more famous Burgess Shale . As such, the Wheeler Shale also represents a Konservat-Lagerstätten .
4-571: Together with the Marjum Formation and lower Weeks Formation , the Wheeler Shale forms 490 to 610 m (1,610 to 2,000 ft) 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
8-582: A heterogeneous succession of highly calcareous shale, shaley limestone, mudstone and thin, flaggy limestone. The Wheeler Formation (although the Marjum & Weeks Formations are missing) extends into the Drum Mountains , northwest of the House Range where similar fossils and preservation are found. Detailed work recognises a number of ~10 m thick lagerstätten sequences in the formation, each of which formed at
12-464: A sea-level high stand 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. The Wheeler Shale spans the Ptychagnostus atavus and uppermost-Middle Cambrian Bolaspidella trilobite zones (See House Range for full stratigraphy). Incomplete list of
16-588: The fauna of the Wheeler Shale: (Note: the preservation of hard bodied trilobite remains and soft bodied animals seems to be mutually exclusive within particular horizons.) Marjum Formation The Marjum Formation is a Cambrian geological formation that overlies the Wheeler Shale in the House Range , Utah . It is named after its type locality, Marjum Pass, and was defined in 1908. The formation
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