TY - JOUR
T1 - The Fukang pallasite
T2 - Characterization and implications for the history of the Main-group parent body
AU - DellaGiustina, Daniella N.
AU - Habib, Namrah
AU - Domanik, Kenneth J.
AU - Hill, Dolores H.
AU - Lauretta, Dante S.
AU - Goreva, Yulia S.
AU - Killgore, Marvin
AU - Hexiong, Yang
AU - Downs, Robert T.
N1 - Funding Information:
This work was supported by NASA Grant NNX07AF96G (PI Dante Lauretta). We are grateful to David Mann for making superb thin sections of the olivine portion. We thank the staff of the University of Arizona Nuclear Reactor Laboratory for assistance with irradiations. We thank the reviewers and editor for their thorough reviews that resulted in greatly improving the manuscript.
Publisher Copyright:
© The Meteoritical Society, 2019.
PY - 2019
Y1 - 2019
N2 - We report the results of a study of the Fukang pallasite that includes measurements of bulk composition, mineral chemistry, mineral structure, and petrology. Fukang is a Main-group pallasite that consists of semiangular olivine grains (Fo 86.3) embedded in an Fe-Ni matrix with 9–10 wt% Ni and low-Ir (45 ppb). Olivine grains sometimes occur in large clusters up to 11 cm across. The Fe-Ni phase is primarily kamacite with accessory taenite and plessite. Minor phases include schreibersite, chromite, merrillite, troilite, and low-Ca pyroxene. We describe a variety of silicate inclusions enclosed in olivine that contain phases rarely or not previously reported in Main-group pallasites, including clinopyroxene (augite), tridymite, K-rich felsic glass, and an unknown Ca-Cr silicate. Pressure constraints determined from tridymite (<0.4 GPa), two-pyroxene barometry (0.39 ± 0.07 GPa), and geophysical calculations that assume pallasite formation at the core–mantle boundary (CMB), provide an upper estimate on the size of the Main-group parent body from which Fukang originated. We conclude that Fukang originated at the CMB of a large differentiated planetesimal 400–680 km in radius.
AB - We report the results of a study of the Fukang pallasite that includes measurements of bulk composition, mineral chemistry, mineral structure, and petrology. Fukang is a Main-group pallasite that consists of semiangular olivine grains (Fo 86.3) embedded in an Fe-Ni matrix with 9–10 wt% Ni and low-Ir (45 ppb). Olivine grains sometimes occur in large clusters up to 11 cm across. The Fe-Ni phase is primarily kamacite with accessory taenite and plessite. Minor phases include schreibersite, chromite, merrillite, troilite, and low-Ca pyroxene. We describe a variety of silicate inclusions enclosed in olivine that contain phases rarely or not previously reported in Main-group pallasites, including clinopyroxene (augite), tridymite, K-rich felsic glass, and an unknown Ca-Cr silicate. Pressure constraints determined from tridymite (<0.4 GPa), two-pyroxene barometry (0.39 ± 0.07 GPa), and geophysical calculations that assume pallasite formation at the core–mantle boundary (CMB), provide an upper estimate on the size of the Main-group parent body from which Fukang originated. We conclude that Fukang originated at the CMB of a large differentiated planetesimal 400–680 km in radius.
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U2 - 10.1111/maps.13313
DO - 10.1111/maps.13313
M3 - Article
AN - SCOPUS:85069897734
VL - 54
SP - 1781
EP - 1807
JO - Meteoritics and Planetary Science
JF - Meteoritics and Planetary Science
SN - 1086-9379
IS - 8
ER -