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

Apt

October’s meteorite of the month is Apt, an (L6) ordinary chondrite that fell October 8, 1803, in the Provence-Alpes-Côte d’Azur region of southeastern France. A report of the fall was …


Upcoming Events

October 2017
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
September 24, 2017 September 25, 2017 September 26, 2017 September 27, 2017 September 28, 2017 September 29, 2017 September 30, 2017
October 1, 2017 October 2, 2017 October 3, 2017 October 4, 2017 October 5, 2017 October 6, 2017 October 7, 2017
October 8, 2017 October 9, 2017 October 10, 2017 October 11, 2017 October 12, 2017 October 13, 2017

Earth and Space Open House

Earth and Space Open House
October 14, 2017
October 15, 2017 October 16, 2017 October 17, 2017

Annual Shoemaker Memorial Lecture

Annual Shoemaker Memorial Lecture
October 18, 2017 October 19, 2017 October 20, 2017 October 21, 2017
October 22, 2017 October 23, 2017 October 24, 2017 October 25, 2017 October 26, 2017 October 27, 2017 October 28, 2017
October 29, 2017 October 30, 2017 October 31, 2017 November 1, 2017 November 2, 2017 November 3, 2017 November 4, 2017