Surface vitrification caused by natural fires in Late Pleistocene wetlands of the Atacama Desert
Author
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Roperch, Pierrick
Author
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Gattacceca, Jerome
Author
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Valenzuela, Millarca
Author
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Devouard, Bertrand
Author
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Lorand, Jean Pierre
Author
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Arriagada Ortega, César
Author
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Rochette, Pierre
Author
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Latorre, Claudio
Author
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Beck, Pierre
Admission date
dc.date.accessioned
2018-03-26T18:29:57Z
Available date
dc.date.available
2018-03-26T18:29:57Z
Publication date
dc.date.issued
2017-07-01
Cita de ítem
dc.identifier.citation
Earth and Planetary Science Letters 469 (2017) 15–26
es_ES
Identifier
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10.1016/j.epsl.2017.04.009
Identifier
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https://repositorio.uchile.cl/handle/2250/147003
Abstract
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We describe extended occurrences of unusual silicate glass surface layers from the Atacama Desert (Chile). These glasses, found near the town of Pica at four localities separated by up to 70 km, are neither fulgurites, nor volcanic glasses, nor metallurgical slags related to anthropic activity, but show close similarities to other glasses that have been previously attributed to large airbursts created by meteoroids entering the Earth's atmosphere. The glasses are restricted to specific Late Pleistocene terrains: paleo-wetlands and soils rich in organic matter with SiO2-rich plant remains, salts and carbonates. C-14 dating and paleomagnetic data indicate that the glasses were formed during at least two distinct periods. This rules out the hypothesis of a single large airburst as the cause of surface melting. Instead, burning of organic-rich soils in dried-out grassy wetlands during climate oscillations between wet and dry periods can account for the formation of the Pica glasses. Large oases did indeed form in the hyperarid Atacama Desert due to elevated groundwater tables and increased surface discharge during the Central Andean Pluvial Event (roughly coeval with the Mystery interval and Younger Dryas). Finally, we discuss the implications of our results for the other surface glasses previously attributed to extraterrestrial events.
es_ES
Patrocinador
dc.description.sponsorship
Programme National de Planetologie (INSU/CNES)
Artemis projects (INSU,CNRS)
OSU Rennes
Fondecyt
3140562
IEB
PFB-23