Carbon-isotope variability of Triassic amber, as compared with wood and leaves (Southern Alps, Italy).

The carbon-isotope signatures of Carnian (Late Triassic) amber drops from Rifugio Dibona (Southern Alps, Italy) were studied and compared with that of other Middle-early Late Triassic fossil plant remains, namely wood and leaves. Amber, wood and leaf carbon-isotope data are highly variable within the same beds. ?13Camber values vary by up to 5.4?and are enriched by ~2.5?with respect to associated wood. ?13Cwood and ?13Cleaf ranges are narrower than that of amber (~2-3?) and the isotopic offset within each bed is similar over time. The high Triassic amber carbon-isotope variability is similar to that of recent resin. Despite the high variability, ?13Cwood and ?13Cleaf illustrate a Middle-early Late Triassic secular positive trend that is similar to that of marine ?13Cinorg data and must record the carbon-isotope evolution of the ocean-atmosphere system.