Emigrant Springs Formation

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.

Geology The Emigrant Springs Formation is predominately composed of various carbonate rocks, and is overlain by the Dunderberg Formation, whilst it is underlain by the Patterson Pass Shale. It also contains three members, which are as follows, in ascending stratigraphic order (lowest to highest):

Members Member A: This member is the thinnest, only getting up to thick, and is composed of medium-gray, thin to medium-bedded calcisiltite and calcilutite, with breccia's in the upper beds of the member. Member B: This member is the thickest, getting up to 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. Member C: This member can get up to thick, and is primarily composed of medium-gray oolitic calcarenite, calcilutite and calcisiltite.

Paleobiota The Emigrant Springs Formation contains a small number of trilobites, and a collection of conodonts, and various molluscs.

Arthropoda

Arthropoda GenusSpeciesNotesImagesCoosina Coosina sp.Ptychoparid trilobite.Blountia Blountia sp.Ptychoparid trilobite.Crepicephalus Crepicephalus sp.Ptychoparid trilobite.Tricrepicephalus Crepicephalus sp.Ptychoparid trilobite.Pemphigaspis Pemphigaspis sp.Ptychoparid trilobite.Elrathia E. alapygePtychoparid trilobite.Cedaria (?) Cedaria (?) sp.Ptychoparid trilobite.Meteoraspis (?) Meteoraspis (?) sp.Ptychoparid trilobite.Baltagnostus Baltagnostus sp. B. eurypyxDiplagnostid agnostid.Hypagnostus Hypagnostus sp.Diplagnostid agnostid.Pseudagnostus Pseudagnostus sp.Agnostid trilobite.Utagnostus U. trispinulusAgnostid trilobite.Kymagnostus (?) Kymagnostus (?) sp.Agnostid trilobite.Lejopyge L. calva Ptychagnostid agnostid.Ptychagnostus Ptychagnostus sp. P. aculeatusPtychagnostid agnostid.Glaphyraspis Glaphyraspis sp.Trilobite.Cheliacephalus Cheliacephalus sp.Trilobite.Aphelaspis Aphelaspis sp.Trilobite.

Chordata

GenusSpeciesNotesImagesHertzina H. bisulcataFurnishinid paraconodont.Westergaardodina W. muelleriWestergaardodinid paraconodont.Furnishina F. asymmetrica F. furnishi F. bicarinataFurnishinid paraconodont.Distacodus D. palmeriDistacodontid conodont.Oneotodus O. tenuisProtopanderodontid tenuis.

Lophotrochozoa

GenusSpeciesNotesImagesHelcionella Helcionella sp.Helcionellid mollusc.Scenella (?) Scenella (?) sp.Scenellid mollusc.Canthylotreta C. cristaAcrotretid brachiopod.Lingulella Lingulella sp.Obolid brachiopod.Livnarssonia L. ophirensisBrachiopod.Paterina Paterina sp.Brachiopod.

Emigrant Springs Formation

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