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Bulk density of ordinary chondrite meteorites and implications for asteroidal internal structure
Author(s) -
WILKISON Sarah L.,
ROBINSON Mark S.
Publication year - 2000
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/j.1945-5100.2000.tb01509.x
Subject(s) - chondrite , meteorite , ordinary chondrite , chemical composition , bulk density , chemistry , analytical chemistry (journal) , mineralogy , group (periodic table) , metal , geology , physics , environmental chemistry , astrobiology , organic chemistry , soil science , soil water
— The bulk densities of 82 samples of 72 ordinary chondrites (OCs) were measured to an accuracy of ∼1% using a modified Archimedian method. We found the average bulk density to be 3.44 ± 0.19 g/cm 3 for the H group, 3.40 ± 0.15 g/cm 3 for the L group, and 3.29 ± 0.17 g/cm 3 for the LL group (± represent 1σ). Bulk density measurements of 11 pieces of one fall, Pultusk (H group), were also found to vary considerably (3.31 to 3.63 g/cm 3 ). To investigate controls on bulk density within the OCs, we compared density with bulk chemical composition (the ratio of Fe metal to total Fe; the ratio of total Fe to SiO 2 ; the ratio of FeO to total Fe and MgO). Within each OC group, bulk chemical composition is nearly invariant whereas bulk density varies from about 3.0 to 3.8 g/cm 3 . Slight but systematic differences in average density between the H, L, and LL groups presumably relate to differences in metallic Fe abundance. However, considerable overlap between OC groups and the wide range of bulk densities within each group suggest differences in porosity dominantly control variations of density within the OC subgroups.