Sediment core 2018_R2_2F was collected from Sheldon Cove, Antarctic Peninsula (67.55°S 68.27°W) from a water depth of 177 m, in December 2018 as part of expedition JR18003 by the British Antarctic Survey aboard RV James Clark Ross (Sands et al. 2019). Total core length was 25 cm. The dataset presented here consists of: gamma spectrometry measurements of excess 210Pb (calculated as a difference between the total 210Pb and the average of 214Pb and 214Bi) and 137Cs; total organic carbon (TOC) content; biogenic silica (BSi) content; and HBI biomarker (IPSO25, HBI III) concentrations. The excess 210Pb and 137Cs were measured at the Institute of Geology at Adam Mickiewicz University in Poznań, Poland, using a gamma detector Canberra BE3830, cooled with cryostat Cryo-Pulse®5 plus. The detector is placed in 10 cm thick lead shield walls and is equipped with a remote detector chamber option (RDC-6 inches) for low energy background reduction. The detector was commercially characterized by ISOCS (In-Situ Object Calibration Software) and LabSOCS (Laboratory Sourceless Object Calibration Software). Efficiencies for measured geometries were determined using LabSOCS code applying all corrections for sample geometry, matrix, and container type, and were verified with IAEA standards measurements. The results (spectra) were analyzed in Canberra GENIE-2000 v. 3.3 gamma spectrometry software and are presented with 2-sigma uncertainty ranges (Szczuciński, submitted). TOC concentrations (given in %) were measured at the Faculty of Earth Sciences, University of Silesia, Poland, using an Eltra CS-500 IRanalyzer with a Total Inorganic Carbon module according to the procedure described in Racka et al. (2010). TOC was calculated as the difference between TC (total carbon) and TIC (total inorganic carbon). Each TOC sample was analysed in duplicate. Analytical precision and accuracy were better than ±2% for TC and ±3% for TIC. HBI biomarker preparation and analysis followed slightly modified (Pieńkowski et al. 2021) standard protocols (Belt 2012). HBI concentrations are given per weight of sediment (ng/g sed), and organic carbon content (μg/g OC) (Belt et al. 2012). Biogenic (opaline) silica (BSi) analysis on dried, homogenised samples followed Heiri et al. (2001) and Bechtel et al. (2007). Each BSi and TOC sample was analysed in duplicate; values are given in %. BSi and TOC standard deviation calculations are based on data from the replication.