TY - JOUR
T1 - Petrography and chemistry of fine-grained dark rims in the mokoia CV3 chondrite
T2 - Evidence for an accretionary origin
AU - Hua, Xin
AU - Zinner, Ernst K.
AU - Buseck, P R
N1 - Funding Information:
Acknowledgments-The Mokoia sample was provided by C. B. Moore and C. Lewis, Center for Meteorite Studies, Arizona State University, USA. We thank A. Bischoff, A. J. Btearley, K. Metzler, and D. W. Mittlefehldt for thorough reviews of the paper. We are grateful to D. D. Eisenhour for helpful discussions and J. Clark for assistance with electron microprobe analyses; tbe electron microprobe was purchased with the aid of NSF grant EAR840816. HX thanks R. Walker and the McDonnell Center for the Space Sciences for their hospitality during her visit to Washington University and the Chinese NSF for sponsoring her visit to China. This study was supported by NASA grants NAGW3386 (PRB) and NAGW3371 (EKZ).
PY - 1996/11
Y1 - 1996/11
N2 - The matrix and fine-grained dark rims (FGDRs) around a type-A Ca-, Al-rich inclusion (CAI) and a silicate aggregate in the Mokoia CV3 chondrite differ in their major, minor, and trace element abundances. The matrix contains more Nb, Sr, Ba, and V but less Ca than average CI chondrite and has an unfractionated rare earth element (REE) pattern. The two FGDRs are enriched in Na, Al, K, and Ti and depleted in Fe and Mn compared to the matrix. The rim surrounding the CAI is enriched in Hf, Y, and Sc relative to the matrix and has a REE pattern that reflects a complex history. The rim surrounding the silicate aggregate has a REE pattern that suggests a different history and, additionally, is complementary to those of the enclosed enstatite and mesostasis glass. The trace element abundances indicate that Mokoia FGDRs are a mixture of components derived from both high-and low-temperature processes, while the matrix consists of only relatively low-temperature materials. These FGDRs in Mokoia have an accretionary origin and were derived from multiple dust reservoirs.
AB - The matrix and fine-grained dark rims (FGDRs) around a type-A Ca-, Al-rich inclusion (CAI) and a silicate aggregate in the Mokoia CV3 chondrite differ in their major, minor, and trace element abundances. The matrix contains more Nb, Sr, Ba, and V but less Ca than average CI chondrite and has an unfractionated rare earth element (REE) pattern. The two FGDRs are enriched in Na, Al, K, and Ti and depleted in Fe and Mn compared to the matrix. The rim surrounding the CAI is enriched in Hf, Y, and Sc relative to the matrix and has a REE pattern that reflects a complex history. The rim surrounding the silicate aggregate has a REE pattern that suggests a different history and, additionally, is complementary to those of the enclosed enstatite and mesostasis glass. The trace element abundances indicate that Mokoia FGDRs are a mixture of components derived from both high-and low-temperature processes, while the matrix consists of only relatively low-temperature materials. These FGDRs in Mokoia have an accretionary origin and were derived from multiple dust reservoirs.
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U2 - 10.1016/S0016-7037(96)00226-8
DO - 10.1016/S0016-7037(96)00226-8
M3 - Article
AN - SCOPUS:0030428422
SN - 0016-7037
VL - 60
SP - 4265
EP - 4274
JO - Geochimica et Cosmochimica Acta
JF - Geochimica et Cosmochimica Acta
IS - 21
ER -