Horse Spring Formation (NVThs;0)

State	Nevada
Name	Horse Spring Formation
Geologic age	Late Oligocene to Middle Miocene
Original map label	Ths
Primary rock type	limestone
Secondary rock type	sandstone
Other rock types	dolostone (dolomite); mudstone; siltstone; evaporite; tuff; lava flow; felsic volcanic rock; intermediate volcanic rock; mafic volcanic rock
Lithologic constituents	Minor Sedimentary > Carbonate > Limestone (Bed) Sedimentary > Clastic > Sandstone (Bed) Incidental Sedimentary > Chemical > Evaporite > Gypsum (Bed) Sedimentary > Chemical > Diatomite (Tuffaceous) Sedimentary > Carbonate > Limestone (Tuffaceous) Sedimentary > Carbonate > Dolostone (Tuffaceous) Sedimentary > Clastic > Mudstone (Tuffaceous) Sedimentary > Clastic > Siltstone (Tuffaceous) Sedimentary > Clastic > Sandstone (Tuffaceous) Sedimentary > Clastic > Conglomerate (Tuffaceous) Sedimentary > Chemical > Diatomite (Bed) Sedimentary > Carbonate > Dolostone (Bed) Sedimentary > Clastic > Conglomerate (Bed) Igneous > Volcanic > Mafic-volcanic (Pyroclastic, tuff) Igneous > Volcanic > Mafic-volcanic (Pyroclastic, ash-flow) Igneous > Volcanic > Mafic-volcanic (Flow) Igneous > Volcanic > Felsic-volcanic (Pyroclastic, tuff) Igneous > Volcanic > Felsic-volcanic (Pyroclastic, ash-flow) Igneous > Volcanic > Felsic-volcanic (Flow) Unconsolidated > Coarse-detrital (Landslide) Sedimentary > Clastic > Mudstone (Bed) Sedimentary > Clastic > Siltstone (Bed)
Map references	Stewart, J.H., and Carlson, J.E., 1978, Geologic Map of Nevada: U.S. Geological Survey and Nevada Bureau of Mines and Geology, 1:500,000 (not part of any formal series, printed and distributed by the U.S. Geological Survey, G75163, reprinted, 1981, G81386).
Unit references	Stewart, J.H., and Carlson, J.E., 1978, Geologic Map of Nevada: U.S. Geological Survey and Nevada Bureau of Mines and Geology, 1:500,000 (not part of any formal series, printed and distributed by the U.S. Geological Survey, G75163, reprinted, 1981, G81386). Stewart, J. H., 1980, Geology of Nevada: A discussion to accompany the Geologic Map of Nevada: Nevada Bureau of Mines and Geology Special Publication 4.
Geographic coverage	Clark - Nye - White Pine