Calcium isotope evidence for environmental variability before and across the Cretaceous-Paleogene mass extinction Linzmeier, Benjamin J. ; Jacobson, Andrew D. ; Sageman, Bradley B. ; Hurtgen, Matthew T. ; Ankney, Meagan E. ; Petersen, Sierra V. ; Tobin, Thomas S. ; Kitch, Gabriella D. ; Wang, Jiuyuan Abstract Publication: Geology Pub Date: January 2020 DOI: 10.1130/G46431.1 Bibcode: 2020Geo....48...34L