The porosities of ordinary chondrites: Models and interpretation

摘要: — Densities and porosities for 285 ordinary chondrites have been assembled analyzed. Measured chondrite are bimodal; finds an average porosity of 30%. We conclude that mild degrees weathering fill pore spaces, lowering grain densities without significantly changing the bulk size or mass sample. By assuming original pristine density (as a function meteorite's mineralogy—determined by its class), we can derive model porosities. These cluster around value 10% all classes chondrites. Ordinary do not show any correlation (model measured) with petrographic grade sample (over range from 0.2 g to 2 kg). However, see between shock state porosity. Shock-blackened meteorites less porous than other meteorites. Furthermore, severely shocked much broader porosities, maximum seen among given class falling linearly as class. This is consistent idea compresses closes space. Analysis meteorite provides lower bound fine-scale asteroids. Our densities, even primordial porosity, higher inferred possible asteroid parent bodies. asteroids probably loose piles rubble.