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Geochemical fingerprinting of Wilson Creek formation tephra layers (Mono Basin, California) using titanomagnetite compositions

Journal of Volcanology and Geothermal Research

By:
, , , ,
DOI: 10.1016/j.jvolgeores.2013.12.008

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Abstract

Nineteen tephra layers within the Wilson Creek formation near Mono Lake provide a record of late Pleistocene to early Holocene volcanic activity from the nearby Mono Craters and are important chronostratigraphic markers for paleomagnetic, paleoclimatic, and paleoecologic studies. These stratigraphically important tephra deposits can be geochemically identified using compositions of their titanomagnetite phenocrysts. Titanomagnetite compositions display a broad range (XUsp 0.26–0.39), which allow the tephra layers to be distinguished despite the indistinguishable major-element glass compositions (76–77 wt% SiO2) of their hosts. The concentrations of Ti and Fe in titanomagnetite display geochemical and stratigraphic groupings that allow clear discrimination between older (> 57 ka) and younger (< 41 ka) tephras. Some individual tephra layers can be uniquely identified on the basis of titanomagnetite MgO, MnO, and Al2O3 contents. In addition, a few tephra layers can be correlated to their source vents by their titanomagnetite compositions. The unique geochemical fingerprint of the Mono Craters-sourced titanomagnetites also allows the discrimination of two tephra layers apparently sourced from nearby Mammoth Mountain volcano in Long Valley.

Geospatial Extents

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Geochemical fingerprinting of Wilson Creek formation tephra layers (Mono Basin, California) using titanomagnetite compositions
Series title:
Journal of Volcanology and Geothermal Research
DOI:
10.1016/j.jvolgeores.2013.12.008
Volume
273
Year Published:
2014
Publisher:
Elsevier
Contributing office(s):
Volcano Science Center
Description:
14 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Country:
United States
State:
California
Other Geospatial:
Mono Basin