Two extraterrestrial dust horizons found in the Dome Fuji ice core, East Antarctica

Year:

2010

Type of Publication:

Artikel

Schlüsselwörter:

meteoroid

Autoren:

Misawa, Keiji; Kohno, Mika; Tomiyama, Takayuki; Noguchi, Takaaki; Nakamura, Tomoki; Nagao, Keisuke; Mikouchi, Takashi; Nishiizumi, Kunihiko

Journal:

Earth and Planetary Science Letters

Volume:

289

Nummer:

1–2

Seiten:

287 - 297

ISSN:

0012-821X

BibTex:

@article{Keiji Misawa2010, author = "Keiji Misawa and Mika Kohno and Takayuki Tomiyama and Takaaki Noguchi and Tomoki Nakamura and Keisuke Nagao and Takashi Mikouchi and Kunihiko Nishiizumi", abstract = "Two silicate-rich dust layers were found in the Dome Fuji ice core in East Antarctica, at Marine Isotope Stages 12 and 13. Morphologies, textures, and chemical compositions of constituent particles reveal that they are high-temperature melting products and are of extraterrestrial origin. Because similar layers were found ∼ 2000 km east of Dome Fuji, at EPICA (European Project for Ice Coring in Antarctica)-Dome C, particles must have rained down over a wide area 434 and 481 ka. The strewn fields occurred over an area of at least 3 × 106 km2. Chemical compositions of constituent phases and oxygen isotopic composition of olivines suggest that the upper dust layer was produced by a high-temperature interaction between silicate-rich melt and water vapor due to an impact explosion or an aerial burst of a chondritic meteoroid on the inland East Antarctic ice sheet. An estimated total mass of the impactor, on the basis of particle flux and distribution area, is at least 3 × 109 kg. A possible parent material of the lower dust layer is a fragment of friable primitive asteroid or comet. A hypervelocity impact of asteroidal/cometary material on the upper atmosphere and an explosion might have produced aggregates of sub-μm to μm-sized spherules. Total mass of the parent material of the lower layer must exceed 1 × 109 kg. The two extraterrestrial horizons, each a few millimeters in thickness, represent regional or global meteoritic events not identified previously in the Southern Hemisphere.", doi = "10.1016/j.epsl.2009.11.016", issn = "0012-821X", journal = "Earth and Planetary Science Letters", keywords = "meteoroid", number = "1–2", pages = "287 - 297", title = "{T}wo extraterrestrial dust horizons found in the {D}ome {F}uji ice core, {E}ast {A}ntarctica", url = "http://www.sciencedirect.com/science/article/pii/S0012821X09006633", volume = "289", year = "2010", }

Kurzzusammenfassung:

Two silicate-rich dust layers were found in the Dome Fuji ice core in East Antarctica, at Marine Isotope Stages 12 and 13. Morphologies, textures, and chemical compositions of constituent particles reveal that they are high-temperature melting products and are of extraterrestrial origin. Because similar layers were found ∼ 2000 km east of Dome Fuji, at EPICA (European Project for Ice Coring in Antarctica)-Dome C, particles must have rained down over a wide area 434 and 481 ka. The strewn fields occurred over an area of at least 3 × 106 km2. Chemical compositions of constituent phases and oxygen isotopic composition of olivines suggest that the upper dust layer was produced by a high-temperature interaction between silicate-rich melt and water vapor due to an impact explosion or an aerial burst of a chondritic meteoroid on the inland East Antarctic ice sheet. An estimated total mass of the impactor, on the basis of particle flux and distribution area, is at least 3 × 109 kg. A possible parent material of the lower dust layer is a fragment of friable primitive asteroid or comet. A hypervelocity impact of asteroidal/cometary material on the upper atmosphere and an explosion might have produced aggregates of sub-μm to μm-sized spherules. Total mass of the parent material of the lower layer must exceed 1 × 109 kg. The two extraterrestrial horizons, each a few millimeters in thickness, represent regional or global meteoritic events not identified previously in the Southern Hemisphere.