Extraterrestrial material in sediments

2007 ◽  
pp. 426-428
Author(s):  
Christian Koeberl
Keyword(s):  
Extraterrestrial Material

Extraterrestrial material in deep-sea deposits

1955 ◽  
Vol 36 (3) ◽  
pp. 385 ◽  
Author(s):  
Taivo Laevastu ◽  
Otto Mellis
Keyword(s):  
Deep Sea ◽  
Extraterrestrial Material

scholarly journals Interstellar and interplanetary solids in the laboratory

2015 ◽  
Vol 11 (A29B) ◽  
pp. 416-419 ◽  
Author(s):  
Emmanuel Dartois ◽  
Ivan Alata ◽  
Cécile Engrand ◽  
Rosario Brunetto ◽  
Jean Duprat ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Environmental Parameters ◽  
Interstellar Matter ◽  
Additional Information ◽  
Set Constraints ◽  
Physico Chemical ◽  
Space Environments ◽  
Chemical Conditions ◽  
Extraterrestrial Material ◽  
Shed Light

AbstractThe composition of interstellar matter is driven by environmental parameters and results from extreme interstellar medium physico-chemical conditions. Astrochemists must rely on remote observations to monitor and analyze the interstellar solids composition. They bring additional information from the study of analogues produced in the laboratory, placed in simulated space environments. Planetologists and cosmochemists access and spectroscopically examine collected extraterrestrial material in the laboratory. Diffuse interstellar medium and molecular clouds observations set constraints on the composition of organic solids that can then be compared with collected extraterrestrial materials analyses, to shed light on their possible links.

RECOVERED EXTRATERRESTRIAL MATERIAL

1970 ◽  
pp. 209-275 ◽  
Author(s):  
D. MAPPER ◽  
A.A. SMALES
Keyword(s):  
Extraterrestrial Material

Antarctic meteorites

1989 ◽  
Vol 1 (1) ◽  
pp. 3-14 ◽  
Author(s):  
A.L. Graham ◽  
John O. Annexstad
Keyword(s):  
Environmental Conditions ◽  
Ice Sheets ◽  
Unknown Number ◽  
The Past ◽  
Lunar Material ◽  
The Earth ◽  
Extraterrestrial Material

Antarctica is currently the most productive region of the Earth for the recovery of meteorites and over 9800 specimens have been found there, most of these since 1969. This material consists of meteoritic fragments representing a much smaller, but unknown, number of distinct meteorites. The particular climatic and environmental conditions of Antarctica result in the recovery of a much larger fraction of the extraterrestrial material that falls to Earth than would be the case in other regions. Remarkable concentrations of meteorites are found in some ‘blue ice’ areas resulting from the movement and ablation of the ice. Most meteorites are believed to have been derived from asteroids less then 200 km in diameter. The discovery in Antarctica of meteorites of lunar material proved that other sources are possible. Indeed two meteorites from Antarctica may have come from the planet Mars. Antarctic meteorites have much older terrestrial ages than non-Antarctic specimens and may be used to obtain information on the movement of the ice sheets in the past.

scholarly journals Estimate of the Influx of Extraterrestrial Material during the Silurian

Nature ◽  
1968 ◽  
Vol 219 (5150) ◽  
pp. 147-147 ◽  
Author(s):  
J. W. MORGAN
Keyword(s):  
Extraterrestrial Material

Oxygen Isotope Ratios in the Crust of Iron Meteorites

1971 ◽  
Vol 26 (9) ◽  
pp. 1485-1490 ◽  
Author(s):  
K. Heinzinger ◽  
C. Iunge ◽  
M. Schidlowski
Keyword(s):  
Oxygen Isotope ◽  
Isotope Ratio ◽  
Atmospheric Oxygen ◽  
Isotope Ratios ◽  
Oxygen Isotope Ratio ◽  
Iron Meteorites ◽  
Oxygen Isotope Ratios ◽  
Cosmic Spherules ◽  
The Difference ◽  
Extraterrestrial Material

Abstract The separation factor, aM-0= (18O/16O) magnetite/' (18O/16O) atmospheric oxygen, between the magnetite crust of iron meteorites and atmospheric oxygen has been determined to be 0.9946 ± 0.0005. It is concluded that this fractionation of the oxygen isotopes is the consequence of an equilibrium isotope effect at high temperatures. It can be assumed that this is also valid for cosmic spherules, which are mainly ablation products of iron meteorites. As these spherules are found in sediments of different geological ages, their oxygen isotope ratio can give information on the development of atmospheric oxygen. The difference of the oxygen isotope ratios between magnetite from the lithosphere and airborne magnetite can be used to distinguish between terrestrial and extraterrestrial material.

scholarly journals A Miocene impact ejecta layer in the pelagic Pacific Ocean

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tatsuo Nozaki ◽  
Junichiro Ohta ◽  
Takaaki Noguchi ◽  
Honami Sato ◽  
Akira Ishikawa ◽  
...  
Keyword(s):  
Northwest Pacific ◽  
Mass Extinctions ◽  
Uncertainty Range ◽  
Meteorite Impacts ◽  
Impact Ejecta ◽  
Isotope Stratigraphy ◽  
Depositional Age ◽  
The Impact ◽  
Extraterrestrial Material ◽  
Os Isotope

AbstractMeteorite impacts have caused catastrophic perturbations to the global environment and mass extinctions throughout the Earth’s history. Here, we present petrographic and geochemical evidence of a possible impact ejecta layer, dating from about 11 Ma, in deep-sea clayey sediment in the Northwest Pacific. This clay layer has high platinum group element (PGE) concentrations and features a conspicuous negative Os isotope anomaly (187Os/188Os as low as ~0.2), indicating an influx of extraterrestrial material. It also contains abundant spherules that include pseudomorphs suggestive of porphyritic olivine as well as spinel grains with euhedral, dendritic and spherical forms and NiO contents as great as 23.3 wt%, consistent with impact ejecta. Osmium isotope stratigraphy suggests a most plausible depositional age of ~11 Ma (Miocene) for this layer, as determined by fitting with the seawater evolution curve. No large impact crater of this age is known on land, even within the relatively large uncertainty range of the relative Os age. Thus, we suggest that an unrecognised impact event in the middle or late Miocene produced the impact ejecta layer of the Northwest Pacific.

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