Marine04 Marine Radiocarbon Age Calibration, 0–26 Cal Kyr Bp

TLDR

The study discusses the Marine04 calibration curve and associated marine data sets for surface mixed‑layer samples. Marine04 was derived from dendrochronologically dated tree‑ring samples converted via a box‑diffusion model for 0–10.5 kyr BP, supplemented by high‑resolution foraminifera and U/Th‑dated coral data beyond 10.5 kyr BP, corrected with site‑specific reservoir ages, and modeled with a random‑walk approach to account for calendar and 14C age uncertainties. The new IntCal04 and Marine04 curves replace IntCal98, extending the calibration range to 0–26 kyr BP with higher resolution, precision, and detailed structure. See this issue.

Abstract

New radiocarbon calibration curves, IntCal04 and Marine04, have been constructed and internationally ratified to replace the terrestrial and marine components of IntCal98. The new calibration data sets extend an additional 2000 yr, from 0–26 cal kyr BP (Before Present, 0 cal BP = AD 1950), and provide much higher resolution, greater precision, and more detailed structure than IntCal98. For the Marine04 curve, dendrochronologically-dated tree-ring samples, converted with a box diffusion model to marine mixed-layer ages, cover the period from 0–10.5 cal kyr BP. Beyond 10.5 cal kyr BP, high-resolution marine data become available from foraminifera in varved sediments and U/Th-dated corals. The marine records are corrected with site-specific 14 C reservoir age information to provide a single global marine mixed-layer calibration from 10.5–26.0 cal kyr BP. A substantial enhancement relative to IntCal98 is the introduction of a random walk model, which takes into account the uncertainty in both the calendar age and the 14 C age to calculate the underlying calibration curve (Buck and Blackwell, this issue). The marine data sets and calibration curve for marine samples from the surface mixed layer (Marine04) are discussed here. The tree-ring data sets, sources of uncertainty, and regional offsets are presented in detail in a companion paper by Reimer et al. (this issue).