Meteorite-Mineralien-Gold-Forum.de
Meteoriten => Tektite ... => Thema gestartet von: karmaka am Februar 05, 2013, 14:55:23 Nachmittag
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Chicxulub, ein Doppelkrater?
http://phys.org/news/2013-02-group-chicxulub-crater-binary-asteroids.html
http://www.sciencedirect.com/science/article/pii/S0012821X12007194
Observational data show that in the Near Earth Asteroid (NEA) region 15% of asteroids are binary. However, the observed number of plausible doublet craters is 2–4% on Earth and 2–3% on Mars. This discrepancy between the percentage of binary asteroids and doublets on Earth and Mars may imply that not all binary systems form a clearly distinguishable doublet crater owing to insufficient separation between the binary components at the point of impact. We simulate the crater morphology formed in close binary asteroid impacts in a planetary environment and the range of possible crater morphologies includes: single (circular or elliptical) craters, overlapping (tear-drop or peanut shaped) craters, as well as clearly distinct, doublet craters. While the majority of binary asteroids impacting Earth or Mars should form a single, circular crater, about one in four are expected to form elongated or overlapping impact craters and one in six are expected to be doublets. This implies that doublets are formed in approximately 2% of all asteroid impacts on Earth and that elongated or overlapping binary impact craters are under-represented in the terrestrial crater record. The classification of a complete range of binary asteroid impact crater structures provides a template for binary asteroid impact crater morphologies, which can help in identifying planetary surface features observed by remote sensing.
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Interessante neue wissenschaftliche Untersuchung zum Chicxulub-Krater!
2008 war ich in Mexiko an der Grenze zu Belize (am Rio Hondo) und habe mir dort die Ejekta-Ablagerungen (Chicxulub-Met.) angeschaut!
Aufgefallen sind mir dort zwei ungewöhnliche braune Ablagerungen/Schichten (nicht eine!) die fast direkt übereinander liegen (siehe Photo)!
Grüsse :hut:
Achim Sven Faforke
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Hallo,
Interessante neue wissenschaftliche Untersuchung zum Chicxulub-Krater!
Ja und nun? Welche Implikationen ergeben sich daraus?
Gruß,
Rainer
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In Deutschland gibt es vergleichbares nämlich die Doppelkrater, das Nördlinger Ries und das Steinheimer Becken!
http://www.gzn.uni-erlangen.de/uploads/media/Noerdlinger__Ries.pdf (http://www.gzn.uni-erlangen.de/uploads/media/Noerdlinger__Ries.pdf)
Möglicherweise ist beim Chicxulub-Meteoriteneinschlag ähnliches geschehen......
Grüsse :hut:
Achim
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Und hier wieder ein alternativer Beitrag zum Thema.
Vielleicht war es auch ein Komet
THE K-PG IMPACTOR WAS LIKELY A HIGH VELOCITY COMET
PDF (http://www.lpi.usra.edu/meetings/lpsc2013/pdf/2431.pdf)
By reassessing and reconciling geo-physical and geochemical evidence for the nature of the K-Pg impactor, we can demonstrate that 99.99% of potential impactor candidates that are coherent with both the geophysical and geochemical data are comets (and 95% are long period comets). This is at odds with the commonly held view that the impactor was a much larger, more slowly travelling asteroid, opening major new directions for the investigation of the K-Pg impact and its effects.