Emigrant Springs Formation

Not to be confused with the Emigrant Formation, a different formation of a similar age.

The Emigrant Springs Formation (Also known as the Emigrant Springs Limestone) is a geologic formation in Nevada. It preserves fossils dating back to the Cambrian period.

Emigrant Springs Formation
Stratigraphic range: Middle Cambrian–Upper Cambrian PreꞒ Ꞓ O S D C P T J K Pg N [1]
Type	Formation
Sub-units	See: Members
Underlies	Dunderberg Formation
Overlies	Patterson Pass Shale
Lithology
Primary	Calcisiltite
Other	Mudstone, Calcilutite, Calcarenite
Location
Region	Nevada
Country	United States

Geology

The Emigrant Springs Formation contains three members, which are as follows, in ascending age:

Members

• Member A: This member is the thinnest, only getting up to 256 ft (78 m) thick, and is composed of medium-gray, thin to medium-bedded calcisiltite and calcilutite, with breccia's in the upper beds of the member.^[1]

• Member B: This member is the thickest, getting up to 1,509 ft (460 m) thick, and is dominated by light-olive-gray, yellowish or pink calcisiltite, which contains silt-sized quartz grains. At the base of this member, there are also mudstones present, transitioning to medium-light-gray, thin to thick-bedded calcisiltite and calcilutite above.^[1]

• Member C: This member can get up to 495 ft (151 m) thick, and is primarily composed of medium-gray oolitic calcarenite, calcilutite and calcisiltite.^[1]

Paleobiota

The Emigrant Springs Formation contains a small number of trilobites,^[1] and a collection of conodonts, and various molluscs.^[2]

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Arthropoda

Arthropoda
Genus	Species	Notes	Images
Coosina[1]	Coosina sp.	Ptychoparid trilobite.
Blountia[1]	Blountia sp.	Ptychoparid trilobite.
Crepicephalus[1]	Crepicephalus sp.	Ptychoparid trilobite.
Tricrepicephalus[1]	Crepicephalus sp.	Ptychoparid trilobite.
Pemphigaspis[1]	Pemphigaspis sp.	Ptychoparid trilobite.
Elrathia[2]	E. alapyge	Ptychoparid trilobite.
Cedaria (?)[1]	Cedaria (?) sp.	Ptychoparid trilobite.
Meteoraspis (?)[1]	Meteoraspis (?) sp.	Ptychoparid trilobite.
Baltagnostus[2]	Baltagnostus sp. B. eurypyx	Diplagnostid agnostid.
Hypagnostus[2]	Hypagnostus sp.	Diplagnostid agnostid.
Pseudagnostus[1]	Pseudagnostus sp.	Agnostid trilobite.
Utagnostus[1]	U. trispinulus	Agnostid trilobite.
Kymagnostus (?)[1]	Kymagnostus (?) sp.	Agnostid trilobite.
Lejopyge[2][1]	L. calva	Ptychagnostid agnostid.
Ptychagnostus[2]	Ptychagnostus sp. P. aculeatus	Ptychagnostid agnostid.
Glaphyraspis[1]	Glaphyraspis sp.	Trilobite.
Cheliacephalus[1]	Cheliacephalus sp.	Trilobite.
Aphelaspis[1]	Aphelaspis sp.	Trilobite.

Chordata

Genus	Species	Notes	Images
Hertzina[2]	H. bisulcata	Furnishinid paraconodont.
Westergaardodina[2]	W. muelleri	Westergaardodinid paraconodont.
Furnishina[2]	F. asymmetrica F. furnishi F. bicarinata	Furnishinid paraconodont.
Distacodus[2]	D. palmeri	Distacodontid conodont.
Oneotodus[2]	O. tenuis	Protopanderodontid tenuis.

Lophotrochozoa

Genus	Species	Notes	Images
Helcionella[2]	Helcionella sp.	Helcionellid mollusc.
Scenella (?)[2]	Scenella (?) sp.	Scenellid mollusc.
Canthylotreta[3]	C. crista	Acrotretid brachiopod.
Lingulella[2]	Lingulella sp.	Obolid brachiopod.
Livnarssonia[2]	L. ophirensis	Brachiopod.
Paterina[2]	Paterina sp.	Brachiopod.

See also

• Earth sciences portal
• United States portal
• Paleontology portal

• List of fossiliferous stratigraphic units in Nevada
• Paleontology in Nevada