The Mule Spring Limestone is a geologic formation in the Saline Range of eastern California and Split Mountain and Goldfield Hills of Nevada. It can also be found outcropping in the Inyo Mountains and White Mountains.
The formation also preserves fossils, primarily trilobites, dating back to the Cambrian period.
Geology The Mule Spring Limestone, as its name suggests, is mainly composed of limestone rocks. These rocks are medium-gray to light-medium-gray, as well as very fine to fine crystalline, and is thin to very thin-bedded in most areas. In the lower sections of the formation, there are also occasional layers, up to thick, of pale-yellowish-brown or greenish-gray shale, limy siltstone and silty limestone. In the Split Mountain, the formation overlies the Harkless Formation and underlies the Emigrant Formation, whilst in other areas it overlies the Saline Valley Formation and underlies the Monola Formation.
Paleobiota The Mule Spring Limestone contains examples of Archaeocyatha, a clade of sponges that went extinct during this time, as well as a collection of trilobites.Mule Spring Limestone Formation Trilobites
Arthropoda
GenusSpeciesNotesImagesBristolia Bristolia sp. B. harringtoni B. insolens B. bristolensis B. anteros B. fragilisBiceratopsid trilobites.Peachella Peachella sp.Biceratopsid trilobite.Mesonacis Mesonacis sp.Olenellid trilobite. Mesonacis sp. previously described as Fremontia sp. which was later synonymised into Mesonacis.Olenellus Olenellus sp. O. puertoblancoensis(?)Olenellid trilobite. Olenellus sp. previously described as Paedumias sp. which was later synonymised into Olenellus.Onchocephalus Onchocephalus sp.Ptychoparid trilobite.Ptychoparioid Ptychoparioid sp. A Ptychoparioid sp. B Ptychoparioid sp. C Ptychoparioid sp. DPtychoparid trilobites.Bonnia Bonnia sp.Dorypygid trilobite.Crassifimbra Crassifimbra sp.Trilobite, family unknown.
Porifera (Sponges)
GenusSpeciesNotesImagesArchaeocyathus Archaeocyathus sp.Archaeocyathide sponge.
Flora
GenusSpeciesNotesImagesGirvanella Girvanella sp.Cyanobacteria structures.
See also
List of fossiliferous stratigraphic units in Nevada Paleontology in Nevada
References