Mathematics – Logic
Scientific paper
Jul 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994metic..29q.441b&link_type=abstract
Meteoritics (ISSN 0026-1114), vol. 29, no. 4, p. 441
Mathematics
Logic
3
Chondrites, Interplanetary Dust, Iron Compounds, Microanalysis, Oxidation, X Ray Absorption, Absorption Spectra, Magnetite, Mineralogy, Potassium Compounds, Trace Elements
Scientific paper
The oxidation states of transition metals in primitive solar system materials are of interest in constraining the oxygen fugacity of early condensation environments. We are exploring the suitability of the micro-X Ray Absorption Near Edge Structure (micro-(XANES) technique for this purpose. Iron-potassium XANES spectra were measured for a single interplanetary dust particle (IDP) and a microfragment of Semarkona matrix. It has been suggested that the Semarkona parent body may be the source of IDPs. The micro-XANES technique is based on precise measurement of the X-ray absorption coefficient while increasing the incident photon energy in small increments. The measurement was done on IDP L2005 J24, a 30-micron particle that was characterized as chondritic based on synchrotron X ray fluorescence (XRF) trace-element analyses. The Zn content was 0.6 x CI indicating a relatively low atmospheric entry heating temperature. Micro-XANES analysis of the IDP showed that the pre-edge peak energy was the same as the position of the pre-edge peak in a magnetite standard, suggesting the presence of Fe(3+) and Fe(2+). The relative intensity of the pre-edge peak, which is an indicator for bonding environment, was much lower than in IDP spectrum as compared to a pure magnetite. This result indicates that most of Fe is not bound in magnetite. Fe-XANES measurement was also performed on a 50-micron fragment of the Semarkona matrix that was isolated from the rest of Semarkona meteorite. The analysis showed that significant amounts of Fe(0), Fe(2+), and Fe(3+) exist in Semarkona matrix. This result is consistent with mineralogical observations indicating that Semarkona matrix consists of fine-grained silicate altered incompletely to smectite and associated with carbides, sulfides, and metal. Based on these limited data, we conclude that on a bulk sample basis, Fe in Semarkona matrix is more reduced than that in at least one IDP.
Bajt Saa
Flynn George James
Sutton Richard S.
No associations
LandOfFree
Iron oxidation state in an interplanetary dust particle and Semarkona matrix by micro-XANES does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Iron oxidation state in an interplanetary dust particle and Semarkona matrix by micro-XANES, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Iron oxidation state in an interplanetary dust particle and Semarkona matrix by micro-XANES will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-822078