¹Florian J. Zurfluh, ^1,2Beda A. Hofmann, ³Edwin Gnos, ¹Urs Eggenberger,⁴A. J. Timothy Jull
Meteoritics & Planetary Science (in Press) Link to Article [DOI: 10.1111/maps.12690]
¹Institut für Geologie, Universität Bern, Bern, Switzerland
²Naturhistorisches Museum der Burgergemeinde Bern, Bern, Switzerland
³Muséum d’histoire naturelle de la Ville de Genève, Genève 6, Switzerland
⁴Department of Geosciences and NSF-Arizona AMS Laboratory, The University of Arizona, Tucson, Arizona, USA
Published by arrangement with John Wiley & Sons

We have investigated 128 14C-dated ordinary chondrites from Oman for macroscopically visible weathering parameters, for thin section-based weathering degrees, and for chemical weathering parameters as analyzed with handheld X-ray fluorescence. These 128 14C-dated meteorites show an abundance maximum of terrestrial age at 19.9 ka, with a mean of 21.0 ka and a pronounced lack of samples between 0 and 10 ka. The weathering degree is evaluated in thin section using a refined weathering scale based on the current W0 to W6 classification of Wlotzka (1993), with five newly included intermediate steps resulting in a total of nine (formerly six) steps. We find significant correlations between terrestrial ages and several macroscopic weathering parameters. The correlation of various chemical parameters including Sr and Ba with terrestrial age is not very pronounced. The microscopic weathering degree of metal and sulfides with newly added intermediate steps shows the best correlation with 14C terrestrial ages, demonstrating the significance of the newly defined weathering steps. We demonstrate that the observed 14C terrestrial age distribution can be modeled from the abundance of meteorites with different weathering degrees, allowing the evaluation of an age-frequency distribution for the whole meteorite population.