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Late Glacial-Holocene tephra from southern Patagonia and Tierra del Fuego (Argentina, Chile): A complete textural and geochemical fingerprinting for distal correlations in the Southern Hemisphere

Fig. 1
Figure 1. Map of southernmost South America showing the locations of the Holocene volcanoes, the extent of the Austral Volcanic Zone of the Andes, and the tephra outcrops studied in this work. Abbreviations: AR, Arroyo Robles; RR, Río Rubens; EO, Estancia Otway; ROH, Río O’Higgins; PA, Punta Arenas; LA, Laguna de los Cisnes; RTB, Río Tres Brazos. The inset shows the Southern Hemisphere with the localities mentioned in the text: F, Dome Fuji; V, Vostok Station; C, Dome C; T, Taylor Dome; A, Andrill; S, Siple Dome; W, WAIS Divide.

Del Carlo P., A. Di Roberto, M. D’Orazio, M. Petrelli, A. Angioletti, G. Zanchetta, V. Maggi, R. Daga, M. Nazzari, S. Rocchi (2018)
Quaternary Science Reviews, 195, 153-170, https://doi.org/10.1016/j.quascirev.2018.07.028

Abstract

Explosive volcanoes from the southern Andes are able to disperse ash over wide areas of the Southern Hemisphere, potentially as far as Antarctica. With the aim of improving correlations between sources and tephra in southernmost South America and, possibly, Antarctica, this work presents new field, textural and geochemical data on tephra layers from southern Patagonia and Tierra del Fuego (Argentina and Chile). Major- and trace-element data, obtained on single glass shards allowed to identify tephra sources in Late Glacial-Holocene eruptions from Hudson, Reclus and Mt Burney volcanoes, located in the Southern and Austral Volcanic Zone of the Andean Cordillera. Twelve new radiocarbon age determinations of charcoals, peats and soils have further constrained the correlations between the studied tephra layers and known eruptions from Hudson, Mt Burney and Reclus volcanoes. Therefore, this study contributes to expand the geochemical dataset on volcanic glasses valuable for tephra correlations in South America, and improves the current tephrostratigraphic framework of this region. Furthermore, we revised literature data by compiling a database including Neogene-Quaternary volcanic tephra found in Antarctic ice cores, marine sediments, blue ice and continental outcrops as well as tephra produced by volcanic sources located in Antarctica and circum-Antarctic areas. This revision shows that Antarctic tephra can be correlated with confidence to Antarctic and circum-Antarctic (South Shetlands and South Sandwich Islands) volcanic sources, whereas correlations with South American sources are arguable, and a complete geochemical fingerprinting is needed for validation.