Physics
Scientific paper
Dec 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010agufm.v23c..05c&link_type=abstract
American Geophysical Union, Fall Meeting 2010, abstract #V23C-05
Physics
[1040] Geochemistry / Radiogenic Isotope Geochemistry, [1060] Geochemistry / Planetary Geochemistry, [1115] Geochronology / Radioisotope Geochronology, [1160] Geochronology / Planetary And Lunar Geochronology
Scientific paper
The early solar system was salted with a number of radioactive isotopes. Some of these have rapid decay rates (half lives of 105 - 108 yr) that offer the opportunity for highly precise age dating (104 - 105 yr precision), compromised somewhat by the low relative abundance of these isotopes and thus the need for extremely high precision isotope ratio determinations to resolve their contribution to the daughter element. The chemical diversity of the elements involved in these short-lived systems allows for the investigation of a number of processes that are important to early solar system evolution, e.g. volatile loss, metal-silicate separation, and igneous differentiation. As with long-lived radioisotope dating systems, accurate chronology based on short-lived radionuclides depends on measurement precision, closure temperature, and an accurately known half-life. Additional factors unique to the short-lived systems include the question of whether the radioactive parent isotope was homogeneously distributed in the solar nebula, the initial abundance of that radioisotope, and whether the isotopic variations in the daughter element result only from radiogenic ingrowth or instead reflect nucleosynthetic heterogeneity in the solar system and/or nuclear reactions caused by energetic particle irradiation. The latter issue is a particular concern for the 53Mn-53Cr, 146Sm-142Nd, and 182Hf-182W chronometers where the stable isotope compositions of the daughter elements have been shown to differ between different meteorite groups. A similar problem recently has been noted in U-Pb dating with detection of variable U isotopic composition in early solar system materials. This issue is critical for the short-lived systems because U-Pb dating is the absolute chronometer most commonly used to anchor the relative time scale provided by extinct radionuclide chronology. In the search for early differentiation at the planetary scale, the short-lived systems have an advantage over long-lived systems in that changes to parent/daughter ratio that occur after the parent has decayed away will not erase the evidence for an ancient age contained in the isotopic variability of the daughter element.
Alexander Clark
Borg Lars E.
Boyet M. M.
Carlson Richard W.
Connelly James
No associations
LandOfFree
Opportunities and Challenges for the Precise Chronology of Solar System Formation (Invited) 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 Opportunities and Challenges for the Precise Chronology of Solar System Formation (Invited), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Opportunities and Challenges for the Precise Chronology of Solar System Formation (Invited) will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1500399