@article { ISI:000379358300021,
	title = {Effects of seafloor diagenesis on planktic foraminiferal radiocarbon ages},
	journal = {GEOLOGY},
	volume = {44},
	number = {{7}},
	year = {2016},
	month = {JUL},
	pages = {551-554},
	type = {Article},
	abstract = {Radiocarbon (C-14) ages obtained from planktic foraminiferal calcite are a mainstay for reconstructing ocean-climate change and carbon cycle dynamics of the past 30 k.y., yet the effects of diagenesis on this vital chronometer are poorly constrained. Here, we address this shortcoming by comparing C-14 ages and trace element ratios (Mg/Ca, Mn/Ca) of planktic foraminifera with white, opaque shells deemed well preserved by traditional standards to those with exquisitely preserved translucent shells. Results support a diagenetic mechanism as opaque shells yield C-14 ages invariably older and trace element ratios consistently higher than those of translucent shells. Radiocarbon age offsets are particularly pronounced in mono-specific samples taken from stratigraphic horizons proximal to the delta O-18 maximum marking the Last Glacial Maximum (LGM) and the subsequent deglacial. Radiocarbon-based calendar ages of translucent shells from the two intervals are congruent with the established age ranges for these climate events, whereas those of co-occurring opaque shells overestimate the LGM and deglacial by 8-15 k.y. and 14-22 k.y., respectively. These results demonstrate that the use of translucent foraminifera enhances reproducibility and accuracy of C-14 ages by minimizing the deleterious effects of diagenesis. This study serves as a cautionary tale since white, opaque foraminifera are common in pelagic sediments, and C-14 ages derived from their ostensibly well-preserved shells can lead to discrepancies in the timing of Quaternary climate events and ocean circulation reconstructions.},
	issn = {0091-7613},
	doi = {10.1130/G37864.1},
	author = {Wycech, Jody and Kelly, D. Clay and Marcott, Shaun}
}
