1.
Science
; 302(5649): 1388-92, 2003 Nov 21.
Article
in English
| MEDLINE
| ID: mdl-14631038
ABSTRACT
Multiple chondritic meteorite fragments have been found in two sedimentary rock samples from an end-Permian bed at Graphite Peak in Antarctica. The Ni/Fe, Co/Ni, and P/Fe ratios in metal grains; the Fe/Mg and Mn/Fe ratios in olivine and pyroxene; and the chemistry of Fe-, Ni-, P-, and S-bearing oxide in the meteorite fragments are typical of CM-type chondritic meteorites. In one sample, the meteoritic fragments are accompanied by more abundant discrete metal grains, which are also found in an end-Permian bed at Meishan, southern China. We discuss the implications of this finding for a suggested global impact event at the Permian-Triassic boundary.
Subject(s)
Geologic Sediments/chemistry , Meteoroids , Minerals/analysis , Animals , Antarctic Regions , Cobalt/analysis , Iron/analysis , Magnesium/analysis , Magnetics , Manganese/analysis , Metals/analysis , Nickel/analysis , Oxides/analysis , Phosphorus/analysis , Plants , Population Density , Silicates/analysis , Sulfides/analysis , Sulfur/analysis , Time
2.
Science
; 300(5619): 584; author reply 584, 2003 Apr 25.
Article
in English
| MEDLINE
| ID: mdl-12714724