Osmium-isotope evidence for volcanism, weathering, and ocean mixing during the early Aptian OAE 1a Bottini, C. ; Cohen, A. S. ; Erba, E. ; Jenkyns, H. C. ; Coe, A. L. Abstract Publication: Geology Pub Date: July 2012 DOI: 10.1130/G33140.1 Bibcode: 2012Geo....40..583B