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. δ¹³C_amber values vary by up to 5.4‰ and are enriched by ~ 2.5‰ with respect to associated wood. δ¹³C_wood and δ¹³C_leaf 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, δ¹³C_wood and δ¹³C_leaf illustrate a Middle-early Late Triassic secular positive trend that is similar to that of marine δ¹³C_inorg data and must record the carbon-isotope evolution of the ocean–atmosphere system.