Libyan Desert Glass area
Transcription
Libyan Desert Glass area
The Hypatia sample locality (Libyan desert) The Hypatia stone locality Libyan Desert Glass area Libyan Desert Glass area Most likely formed as a result of melting of the Cretaceous sandstones from the area at ~29 Ma The place where Hypatia was collected ‘Hypatia’ - carbonado-like material Kramers et al, in press Kramers et al, in press Kramers et al, in press MD-PianoTM 120 1 mm 0.1 mm 50 µm Microdiamonds? Kramers et al, in press Raman spectroscopy of the carbonaceous matrix ~99 wt.% carbon, ~1 wt.% oxygen 2 major phases: nickel phosphide (Ni:P=5:1) 50 µm iron sulphide (Fe:S=1:1) BSE S Fe Mg C Al Ni P Si K O Ca 100 µm Additional metallic (no oxygen) phases present in Hypatia Al 50 µm Zn 10 µm Ag 20 µm Ce+Si 10 µm Fe 25 µm La+Si 20 µm argyrodite Organics (extremophiles?) 50 µm 100 µm 25 µm 25 µm Thermally unprocessed carbon From McCall, 2009 Discussion The Hypatia stone’s chemistry and structure are most closely reminiscent to that of carbonado diamond. Noble gases isotopes data indicate that the Hypatia is a remnant of a cometary nucleus fragment that impacted after incorporating gases from the Earth atmosphere, having caused the formation of the Libyan Desert Glass (Kramers et al., in press). An unique mineralogy of the sample (diamond, nickel phosphide, troilite, silicon carbide, along with various metallic inclusions) also supports extraterrestrial genesis. Furthermore, the mysterious development of organic matter in the sample was most likely triggered by its unusual chemical composition.