Sample preparation parameters and stable carbon and oxygen isotope records of Globigerina bulloides and Cibicidoides wuellerstorfi from IODP Site 306-U1313 in the North Atlantic during Marine Isotope Stage (MIS) 36 to 44

This dataset contains sample preparation parameters and stable carbon and oxygen isotope measurements from IODP Site 306-U1313, located in the central North Atlantic Ocean northeast of the Azores Islands (41°0.08'N, 32°57.4'W; 3426 m water depth). The record spans Marine Isotope Stages 36 to 44 during the Early Pleistocene and includes wet weight, dry weight, coarse fraction weight, and stable isotope data obtained from planktonic and benthic foraminifera.Sediment samples were processed following the standard procedures of the Sedimentology and Micropaleontology Laboratory of the Divisão de Geologia e Georecursos Marinhos (DivGM), Instituto Português do Mar e da Atmosfera (IPMA). Samples were weighed before and after freeze-drying to determine dry weight, washed through a 63 μm sieve, and the coarse fraction was dried and weighed. Stable carbon (δ¹³C) and oxygen (δ¹⁸O) isotope measurements were performed on the planktonic foraminifer Globigerina bulloides and the benthic foraminifera Cibicidoides wuellerstorfi at the Leibniz Laboratory for Radiometric Dating and Stable Isotope Research (Kiel University, Germany) using a Finnigan MAT 253 mass spectrometer coupled to a Kiel IV carbonate preparation device. Isotope values are reported relative to the Vienna Pee Dee Belemnite (VPDB) standard. The age model is based on correlation of the planktonic δ¹⁸O record of G. bulloides to the high-resolution isotope record from IODP Site 339-U1385. The dataset contains stable isotope and sample preparation data for IODP Site 306-U1313 and provides chronological and paleoceanographic information for the North Atlantic during the Early Pleistocene. The data support investigations of glacial-interglacial variability and surface-deep-water changes.