کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4463329 1621645 2016 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A new Eemian record of Antarctic tephra layers retrieved from the Talos Dome ice core (Northern Victoria Land)
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
A new Eemian record of Antarctic tephra layers retrieved from the Talos Dome ice core (Northern Victoria Land)
چکیده انگلیسی


• 13 new visible tephra layers from an accurately dated Antarctic ice core documented
• Tephra characterisation based on grain size, glass-shard geochemistry and isotope stratigraphy
• Dominant sources are the Northern Victoria Land volcanoes.
• The Last Interglacial tephrostratigraphic framework for the Antarctic ice sheet is enhanced.
• Reconstruction of the local explosive volcanic activity is considerably improved.

Polar ice sheets are remarkable repositories of tephra layers. The Talos Dome ice core (72°49′S, 159°11′E), drilled at the edge of the East Antarctic Plateau, close to Late Quaternary volcanoes, offers considerable potential to extend the current tephra time-stratigraphic framework. A tephrochronological study was undertaken of the ice core sections related to the Last Interglacial and the transition to the subsequent glacial period. Thirteen macroscopically visible layers, interpreted to be related to primary deposition of fallout tephra, have been analysed for quantitative grain size and glass shard geochemistry. The layers, precisely framed within the climate (δ18O) record for the core, span in age from 111.6 ± 1.9 to 123.3 ± 2.2 ka. Coarse particle size suggests origin from regional sources. Indeed, the vast majority of the samples display an alkaline affinity and trachytic composition that are both typical geochemical features of rifting Antarctic volcanism. Using subtle differences in the geochemical signatures and the comparison with data from previous studies, a few layers are attributed to known coeval Mt. Melbourne eruptions. Another sample subset is consistent with derivation from The Pleiades and Mt. Rittmann volcanoes. One peculiar trachytic glass population appears to be related to activity of the more distant Marie Byrd Land volcanoes. The newly detected tephras provide stratigraphic markers that could facilitate future synchronisation and dating of palaeoclimatic records. The Talos Dome tephra inventory also contributes significantly to the reconstruction of the Northern Victoria Land explosive volcanism, for which chronostratigraphic data for the Last Interglacial temporal segment are poor.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Global and Planetary Change - Volume 137, February 2016, Pages 69–78
نویسندگان
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