Center for Meteorite Studies

The ASU Center for Meteorite Studies is pleased to announce that Emily Worsham, a graduate student at the University of Maryland, is the recipient of the 2016 Nininger Meteorite Award.

Emily WorshamEmily's paper “Siderophile element systematics of IAB complex iron meteorites: New insights into the formation of an enigmatic group” (coauthored by Katherine Bermingham, and Richard Walker) addresses the disputed origins of IAB iron meteorites. The IAB complex is a large group of chemically and texturally similar meteorites containing a main group and several chemical subgroups. The complex likely represent metals with a thermal history unlike most other iron meteorite groups, which sample the fractionally-crystallized cores of differentiated planetesimals. Opposing models for the formation of the IAB complex invoke either an internal (decay of 26Al) or external (impact-generated) heat source. This paper details a comprehensive study of highly siderophile element (HSE) characteristics and Re-Os isotope systematics, along with trace element modeling within the subgroups, to elucidate the crystallization mechanisms of IAB melts and the degree of differentiation of the IAB parent body(ies).

The absolute and relative HSE abundances indicate that the IAB subgroups formed from a minimum of five separate parental melts. Most subgroups crystallized by complex crystal-liquid fractionation and mixing processes, indicating that the initial melts may have been impact-generated. The characteristics which distinguish some IAB complex irons from fractionally-crystallized iron meteorite groups likely originated because of their formation on undifferentiated parent bodies where impacting and mixing processes were important. Thus, many IAB irons appear to sample a type of parent body intermediate between primitive and fully differentiated parent bodies; a finding which has implications for why and how some asteroids differentiated into a core, mantle, and crust, and why some did not.


Category: CMS News

Comments are closed.

Facebook
Twitter
YouTube

Sign Up for Center Updates!

Be the first to learn about CMS events and news; sign up for email updates here!


Postdoctoral Scholar Opportunities!

The Center for Meteorite Studies at Arizona State University invites applications for 2 Postdoctoral Research Associates.  Click here for details!




Meteorite of the Month

Noblesville

August's Meteorite of the Month is Noblesville, an ordinary (H4-6) chondrite that fell in Indiana, the evening of August 1st, 1991. According to the Meteoritical Bulletin (MB 72): "The stone …


Upcoming Events

August 2017
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
July 30, 2017 July 31, 2017 August 1, 2017 August 2, 2017 August 3, 2017 August 4, 2017 August 5, 2017
August 6, 2017 August 7, 2017 August 8, 2017 August 9, 2017 August 10, 2017 August 11, 2017 August 12, 2017
August 13, 2017 August 14, 2017 August 15, 2017 August 16, 2017 August 17, 2017 August 18, 2017 August 19, 2017
August 20, 2017 August 21, 2017

Celebrate the Solar Eclipse at ASU!

Celebrate the Solar Eclipse at ASU!
August 22, 2017 August 23, 2017 August 24, 2017 August 25, 2017 August 26, 2017
August 27, 2017 August 28, 2017 August 29, 2017 August 30, 2017 August 31, 2017 September 1, 2017 September 2, 2017