Revised marine reservoir offset ( <scp>ΔR</scp> ) values for molluscs and marine mammals from Arctic North America

Appropriate marine–terrestrial reservoir offset (ΔR) values are essential for accurate calibration of marine radiocarbon dates. However, ΔR only valid the specific curve that their calculation is based on. Here, we present revised Marine20 from Arctic North America, on previously published 14C dates pre-bomb live-collected molluscs (n = 124) and cetaceans (beluga whales; tooth dentine; n 12), bowhead whale–driftwood age comparisons same glacio-isostatically uplifted shorelines 18). Molluscan-based are: Chukchi/Beaufort sea coasts, 265±116 years; NW Canadian Archipelago, 188±91 NE Baffin Island, 81±18 SE 14±58 Hudson Strait, −73±64 Ungava Bay, 0±86 Foxe Basin, 175±89 −21±72 James 209±114 West Greenland, −93±111 years. Species-specific mammal terms 107±59 years beluga 24±58 bowheads. Our applicable as long broad oceanographic conditions (circulation, ventilation) have persisted, i.e. through Holocene. While molluscan to other carbonate (e.g. foraminifera), cetacean species they were calculated should not be applied mammals. Importantly, here used with earlier or later curves.