1,2Alan E. Rubin
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13626]
1Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, California, 90095‐1567 USA
2Maine Mineral & Gem Museum, 99 Main Street, P.O. Box 500, Bethel, Maine, 04217 USA
Published by arrangement with John Wiley & Sons
For ordinary‐chondrite (OC) mass distributions, Benford’s law applies to the set of individual objects that survive intact on the Earth’s surface after atmospheric disruption of meteoroids. Among OCs, Antarctic finds conform more closely to Benford’s law than observed falls, Northwest Africa (NWA) finds, or Oman finds mainly because Antarctic OCs tend to be relatively unweathered (and mostly intact) and have not been aggregated as pairs under collective meteorite names. Deviations from Benford’s law can result from tampering with data sets. The set of OC falls reflects tampering with the original Benford distribution (produced by meteoroid disruption) by the deliberate aggregation of paired individual samples and inefficiencies in the collection of small samples. The sets of NWA and Oman OC finds have been affected by natural “tampering” of the original distributions principally by terrestrial weathering, which can cause sample disintegration. NWA finds were also affected by non‐systematic collection of samples influenced by commercial considerations; collectors preferred type‐3 OC as revealed by the high proportions of such specimens among NWA chondrites relative to those among falls and Oman and Antarctic finds. The percentage of type‐4 OC among falls is appreciably lower than in the sets of finds. This suggests that type‐4 chondrites are friable and disintegrate into numerous pieces; these are counted individually for the sets of finds, but collectively for falls. However, the fact that the percentages of type‐3 OC are not generally higher for finds may be that these samples tend to break into small pieces that are preferentially lost.
1,2Alan E. Rubin