The Emigrant Formation is a Cambrian to Ordovician geologic formation in Nevada. It preserves fossils dating back to the Cambrian period, as well as the Ordovician period.
The Emigrant Formation is dominated by shales, with limestone common at the base and top of the formation.
The formation contains three members, which are as follows, in ascending age:
The Emigrant Formation also contains lower Ordovician aged rocks above the Limestone & Chert Member, informally known as the "Platy Limestone Unit". This unit is primarily composed of fine-grained, platy limestone, which are inter-bedded with pale-red siltstone. The very top of the unit is not preserved, and contacts the overlying Palmetto Formation at a fault, and the unit itself is also difficult to age, although a lower Ordovician age is suggested, though more evidence will be needed to pinpoint the exact age of the unit. It has also been noted that this unit may represent a transitional bed between the Emigrant and Palmetto Formations.
The biota of the Emigrant Formation is mainly composed of trilobites like Olenellus and Bathyuriscus, as well as some small shelly fauna in the form of Pelagiella and Microcornus. It also contains a sparse collection of fossils from a lower Ordovician unit right at the top of the formation, containing the chelicerate Esmeraldacaris, as well as some graptolite fauna.
This section details all the fossils from the Cambrian sections of the Emigrant formation.
This section details all the fossils from the Ordovician unit at the top of the Emigrant Formation.