The

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozo ...

McKenzie Formation is a mapped

bedrock In geology, bedrock is solid Rock (geology), rock that lies under loose material (regolith) within the crust (geology), crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface mater ...

unit in Maryland.

Description

The McKenzie Formation is a gray, thin-bedded

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...

and argillaceous limestone, with interbedded red sandstone and shale in its eastern extents in Maryland. The thickness ranges from 160 to 380 feet. It houses shallow water fauna including but not limited to brachiopods, Ostracods, and tentaculitids.

Age

Relative age dating of the Tuscarora places it in the

period. It rests conformably atop the

Clinton Group The Clinton Group (also referred to as the Clinton Formation or the Clinton Shale) is a mapped unit of sedimentary rock found throughout eastern North America. The interval was first defined by the geologist Lardner Vanuxem, who derived the name f ...

and conformably below the Bloomsburg Formation.

References

Silurian Maryland Silurian West Virginia Silurian geology of Virginia Silurian southern paleotemperate deposits Ludfordian {{Maryland-geologic-formation-stub