Benthic and planktic foraminiferal stable carbon isotope ratios (δ¹³C) at IODP Site 383-U1540 during Marine Isotope Stage 12-11

This dataset presents stable carbon isotope ratios measured on the benthic foraminifera Cibicidoides wuellerstorfi and Cibicides kullenbergi and on the planktic foraminifera Globigerina bulloides at International Ocean Discovery Program Site U1540 (55° 8.47ʹ S, 114° 50.52ʹ W; 3,580 m) during Marine Isotope Stage 12-11. Full replicates were conducted to determine the 1σ-uncertainty of the analyses. The results are expressed in delta-notation (δ¹³C) with reference to the Vienna Pee Dee Belemnite (VPDB) standard. The samples were measured with a Thermo Fisher Scientific MAT 253 isotope ratio mass spectrometer coupled to a Kiel IV carbonate preparation device at the Leibniz Laboratory for Radiometric Dating and Stable Isotope Research at Kiel University (Kiel, Germany). This dataset complements the δ13C dataset from Jebasinski et al. (2026; https://doi.org/10.1594/PANGAEA.985523).