Alkaline Rocks and Carbonatites of the World

Setup during HiTech AlkCarb: an online database of alkaline rock and carbonatite occurrences

Lunar Crater Volcanic Field

stripes

Occurrence number: 
174-00-156
Country: 
United States
Region: 
Nevada
Location: 
Longitude: -115.9557, Latitude: 38.53778
Carbonatite: 
No

Lunar Crater volcanic field (LCVF) is a ~90 km long, ~5-15 km wide belt of volcanoes located in Basin and Range Province of central Nevada. It is composed of ~161 volcanoes exposed in and around two mountain ranges: the Reveille and Pancake Ranges to the south and north respectively. Older late Miocene-Pliocene extrusives are mainly in the Reveille Range with younger Pliocene-Pleistocene extrusives in the Pancake Range. Structures within the LCVF include maars, dikes, sills, agglomerate ramparts, and spatter cones. Four magmatic episodes are distinguished in this locality and are described as follows: Episode 1 composed of alkalic, hawaiitic basalts bearing megacrysts of labradorite; Episode 2 rocks are alkalic ranging from basanite to trachyte, with most being nepheline normative; Episode 3 rocks are alkalic basalts to trachyandesite commonly with gabbroic inclusions; and Episode 4 includes tephrites, basanites, and trachybasalts entraining a range of ultramafic inclusions. Episodes 3 and 4 only occur in and around the Pancake Range. The range of compositions of the different magma batches is interpreted to result from a heterogeneous garnet lherzolite/olivine websterite source undergoing ~3-5% partial melting. Specific descriptions and geochemical analyses of four informally named localities from the northern part of the LCVF (Hi Desert Basalt, Mizpah Basalt, Giggle Springs Basalt, and Marcath/Black Rock Basalt) can be found in Cortes et al. (2015) and detailed information and geochemical analysis of the volcanic field as a whole can be found in Valentine et al. (2017).

Age: 
Intermittent over 6 – 0.035 Ma K-Ar, Ar-Ar, and 10Be (Valentine et al., 2017)
References: 

CORTES, J.A., SMITH, E., VALENTINE, G., JOHNSEN, R., RASOAZANAMPARANY, C., WIDOM, E., SAS, M. & RUTH, D., 2015. Intrinsic conditions of magma genesis at the Lunar Crater Volcanic Field (Nevada), and implications for internal plumbing and magma ascent. American Mineralogist 100 pp 396. VALENTINE, G.A., CORTES, J.A., WIDOM, E., SMITH, E.I., RASOAZANAMPARANY, C., JOHNSEN, R., BRINER, J.P., HARP, A.G. & TURRIN, B., 2017. Lunar Crater volcanic field (Reveille and Pancake Ranges, Basin and Range Province, Nevada, USA. Geosphere 13:2 pp 391-438

See Fig 4 and 5 for detailed geological map of the northern and southern LCVF (Valentine et al, 2017)
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith