• Program

    The Goldschmidt2020 program

  • Venue

    All about the venue and city

  • Registration

    Details of how to register to attend the conference and/or submit an abstract

  • Exhibition

    Information for and about exhibitors and sponsors

  • My Goldschmidt

    My program, purchases, connections, etc.




  • Sponsor Seminars

  • Training Events

    These are scheduled events to help delegates test out the tools and platform we will be using for the Q&A and other events at the conference.

  • Workshops

    Our workshop program provides training and teaching in topics across geochemistry and related fields. We are currently liaising with the workshop organisers to ascertain if any workshops can become virtual. Any updates will be added to this page.


  • Conference Locations

    Location of the convention center and social events

  • Hotels

    The hotels are no longer available to book at the special rates agreed by the conference. Should you wish to cancel or change your hotel reservation please see the details below.


Present your work




My Goldschmidt

Role functions

Abstract Details

(2020) Younger Al-Mg Ages of Chondrules in CO Chondrites Than L/LL Chondrites

Kita N, Fukuda K, Siron G & Kimura M


Sorry, the PDF cannot be displayed on your browser.

Download abstract

The author has not provided any additional details.

01g: Plenary Hall, View in program

Listed below are questions that have been submitted by the community that the author will try and cover in their presentation. To submit a question, ensure you are signed in to the website. Authors or session conveners approve questions before they are displayed here.

Submitted by Quinn Shollenberger on
How do your Al-Mg ages of OC chondrules compare with other isotopic systems? (e.g., Hf-W)
Al-Mg system and Hf-W have been compared for CR chondrules and they seem to show agreements, though there is a caveat using Al-Mg data of chondrules without resolvable 26Mg excess. Fo OC chondrules, we may compare Hf-W study for types 4-6 chondrites, suggesting ~2 Ma to 2.7 Ma for chondrule formation (Hellman et al. 2019). Though it is not direct comparison and need thermal modeling, estimated time generally agree with Al-Mg ages of UOCs. Thermal history of OC suggest accretion time of 2.14±0.1 Ma (Sugiura and Fujiya, 2014), which agree very well with new Al-Mg chondrule data by Siron et al. (2020). Because of relatively narrow range of Al-Mg ages in UOCs, pooled chondrule analyses using other chronometers will provide useful comparisons.

Submitted by Alison Hunt on
If you chose chondrules from the upper and lower ends of the Type I and II ranges defined by Kurahashi et al. 2008, would you also get a larger range of formation times? Do you have any plans to measure more chondrules?
It is possible to find relatively older chondrule, similar to those found in In Acfer 094. Youngest chondrules in Y-81020 are small chondrule fragments with Na-rich plagioclase that are exposed to matrix. Y-81020 is very pristine, yet subtype 3.05. I have some concerns to use this meteorite for Na-rich plagioclase analyses (even though I obtained fairly good isochron). We have a plan to study DOM 08006 (CO3.01) with minimal thermal metamorphism to answer this question.

Submitted by Emily Worsham on
If chondrule formation generally progressed with greater heliocentric distance (or less given the previous presentation), what physical or chemical disk properties would this correspond to/correlate with? Does this tell us anything about the chondrule forming process?
Considering that chondrule formation many need large planetesimal or planetary embryos, either by bow shock, by gravitational instability, or by impact, timing of chondrule formation would be related to growth of planetary bodies in each regions. Growth was earlier in inner disk than outer disk where CC parent bodies formed. Mg# of chondrule minerals are systematically different between OC and CC. OC show a broad distribution of Mg# (100-70), while CC show a sharp peak at very high Mg# 99-98. OC chondrules formed in more dust-rich regions than most chondrules in CC.

Sign in to ask a question.