Geochemical fingerprinting of Wilson Creek formation tephra layers (Mono Basin, California) using titanomagnetite compositions
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.
Citation Information
Publication Year | 2014 |
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Title | Geochemical fingerprinting of Wilson Creek formation tephra layers (Mono Basin, California) using titanomagnetite compositions |
DOI | 10.1016/j.jvolgeores.2013.12.008 |
Authors | Mae Marcaida, Margaret T. Mangan, Jorge A. Vazquez, Marcus Bursik, Marsha I. Lidzbarski |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Journal of Volcanology and Geothermal Research |
Index ID | 70074470 |
Record Source | USGS Publications Warehouse |
USGS Organization | Volcano Hazards Program; Volcano Science Center |