Notes from the Field

Chondrules are melt spherules in meteorites. Whether chondrules are universally primitive condensates from the solar nebula or spherules produced by planetesimal collisions during planetary accretion is uncertain. Emeritus Professor Roger Hewins and Ph.D. alumna Claire Condie defined the formation conditions of some unusual chondrules, which partially remelted during cooling (see Condie’s 2012 EPS Ph.D. thesis). Melissa Morris’ group at SUNY Cortlandt used Condie’s data to conduct 3D modeling of an impact plume with the adaptive mesh refinement code FLASH4. They found heating spikes in compressed parcels of gas like those in crystallization experiments. The agreement between the geological experiments from Rutgers and the astrophysical models from SUNY Cortlandt supports formation of these chondrules by collision of planetesimals

 Left, a normal barred olivine chondrule. Middle, a skeletal barred olivine chondrule from a CBb chondrite. Right, an experimental charge with skeletal barred olivine.

           Dr. Claire Condie                                                                     Dr. Roger Hewins

To learn more, check out the following papers:

R. Hewins, C. Condie, M. Morris, M. Richardson, N. Oullette, and M. Metcalf. (2018) Thermal history of CBb chondrules and cooling rate distributions of ejecta plumes. The Astrophysical Journal Letters, 855:L17 (7pp).

C. Condie (2012) The use of experimental petrology to generate an impact model as the formation mechanism for the unique CB chondrules. RU EPS Ph.D. thesis.