About the Authors

Lora R. McGuinness

Affiliation Department of Marine and Coastal Science, Rutgers University, New Brunswick, NJ, United States of America

Michael J. Wilkins

Affiliation School of Earth Sciences, Ohio State University, Columbus, OH, United States of America

Kenneth H. Williams

Affiliation Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America

Philip E. Long

Affiliation Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America

Lee J. Kerkhof

lkerkhof@rutgers.edu

Affiliation Department of Marine and Coastal Science, Rutgers University, New Brunswick, NJ, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: LJK LRM. Performed the experiments: LRM LJK. Analyzed the data: LRM LJK KHW. Contributed reagents/materials/analysis tools: LRM KHW MJW LJK. Wrote the paper: LRM MJW KHW PEL LJK. Overall Rifle Field Project: PEL KHW. 2007-2009 field sampling: LRM KHW MJW LJK.