Computer Science
Scientific paper
Sep 1992
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992lmip.conf...25e&link_type=abstract
In Lunar and Planetary Inst., International Conference on Large Meteorite Impacts and Planetary Evolution p 25 (SEE N93-10112 01
Computer Science
Chondrites, Clays, Cretaceous-Tertiary Boundary, Ejecta, Fractionation, Inclusions, Meteorite Collisions, Meteoritic Composition, Basalt, Igneous Rocks, Iridium, Meteoritic Damage, Platinum, Quartz, Ruthenium, Volcanoes
Scientific paper
Ruthenium (Ru) and iridium (Ir) are the least mobile platinum group elements (PGE's) within the Cretaceous-Tertiary (K-T) boundary clay (BC). The Ru/Ir ratio is, therefore, the most useful PGE interelement ratio for distinguishing terrestrial and extraterrestrial contributions to the BC. The Ru/Ir ratio of marine K-T sections (1.77 +/- 0.53) is statistically different from that of the continental sections (0.93 +/- 0.28). The marine Ru/Ir ratios are chondritic (C1 = 1.48 +/- 0.09), but the continental ratios are not. We discovered an inverse correlation of shocked quartz size (or distance from the impact site) and Ru/Ir ratio. This correlation may arise from the difference in Ru and Ir vaporization temperature and/or fractionation during condensation from the ejecta cloud. Postsedimentary alteration, remobilization, or terrestrial PGE input may be responsible for the Ru/Ir ratio variations within the groups of marine and continental sites studied. The marine ratios could also be attained if approximately 15 percent of the boundary metals were contributed by Deccan Trap emissions. However, volcanic emissions could not have been the principal source of the PGE's in the BC because mantle PGE ratios and abundances are inconsistent with those measured in the clay. The Ru/Ir values for pristine Tertiary mantle xenoliths (2.6 +/- 0.48), picrites (4.1 +/- 1.8), and Deccan Trap basalt (3.42 +/- 1.96) are all statistically distinct from those measured in the K-T BC.
Evans Noreen Joyce
Goodfellow Wayne D.
Gregoire Conrad D.
Veizer Ján
No associations
LandOfFree
Ruthenium/iridium ratios in the Cretaceous-Tertiary boundary clay: Implications for global dispersal and fractionation within the ejecta cloud does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Ruthenium/iridium ratios in the Cretaceous-Tertiary boundary clay: Implications for global dispersal and fractionation within the ejecta cloud, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ruthenium/iridium ratios in the Cretaceous-Tertiary boundary clay: Implications for global dispersal and fractionation within the ejecta cloud will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1769354