A terrestrial origin for sulfate veins in CI1 chondrites

White sulfate veins are a very well-known petrological feature of the chemi cally primitive CI1 carbonaceous chondrites. Sulfate veins were first descr ibed in the Orgueil meteorite in 1961, almost one century after its fall. H owever, we have observed such veins to form easily during typical sample st orage. We suggest that all CI1 sulfate veins formed during the terrestrial residence of these heavily brecciated, porous stones. Reacting with atmosph eric water, sulfates originally present in the meteorites dissolved and rem obilized, and/or sulfides oxidised, filling the many open spaces offered to them by the very porous rock. Sulfate veins in CI1 chondrites can no longe r be used as evidence of a late-stage oxidation event in the CI1 parent bod y, or of centimeter-scale fluid transport on the parent asteroid.