Marjum formation
Encyclopedia
The Marjum formation is a Cambrian
geological formation that overlies the Wheeler Shale
in the House Range
, Utah
. It is known for its occasional preservation of soft-bodied tissue, and is slightly younger than the Burgess Shale
, falling in the Ptychagnostus
praecurrens trilobite zone
.
Cambrian
The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...
geological formation that overlies the Wheeler Shale
Wheeler Shale
The Wheeler Shale is a Cambrian fossil locality world famousfor prolific agnostid and Elrathia kingii trilobite remains...
in the House Range
House Range
The House Range is a north-south trending mountain range in west-central Utah. It is famous for Notch Peak, one of the tallest limestone cliffs in the world, and a fossil Lagerstätte of Cambrian age, which has an array of Burgess Shale type fauna, including Elrathia kingii, a trilobite that is...
, Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
. It is known for its occasional preservation of soft-bodied tissue, and is slightly younger than the Burgess Shale
Burgess Shale
The Burgess Shale Formation, located in the Canadian Rockies of British Columbia, is one of the world's most celebrated fossil fields, and the best of its kind. It is famous for the exceptional preservation of the soft parts of its fossils...
, falling in the Ptychagnostus
Ptychagnostus
Ptychagnostus is an extinct genus of blind trilobite that lived during the Cambrian period, part of the order Agnostida. Ptychagnostidae generally do not exceed ten millimetres in length. Their remains are sometimes found in the otherwise empty tubes of the polychaete worm Selkirkia. It probably...
praecurrens trilobite zone
Trilobite zone
Trilobites are used as index fossils to subdivide the Cambrian period. Assemblages of trilobites define trilobite zones. The Olenellus zone has traditionally marked the top of the Lower Cambrian, and is followed by the Eokochaspis zone....
.