The Beyond EPICA Oldest Ice Impurities Continuous Flow Analysis

We present an optimised impurities continuous-flow analysis (CFA) method specifically developed to analyse the Beyond EPICA Oldest Ice Core (BE-OIC; >700 ky bp). Hosted at the British Antarctic Survey (BAS1) and operated collaboratively with our BE-OI partners2-12, the new CFA method was designed to operate at a melt rate of 1.5 cm min-1. The system included the continuous analyses of trace elements (triple quadrupole inductively-coupled plasma mass spectrometry, Agilent 8900 ICP-QQQ-MS/MS & inductively-coupled plasma optical emission spectroscopy, Agilent 5900 ICP-OES; BAS1); major anions (Cl-, SO42-, NO3- and MSA, Dionex fast ion chromatography, FIC; BAS1); NH4+ (fluorometry; BAS1); electrolytic conductivity (Dionex CDM-1 & Amber Science ECM 3201; BAS1); insoluble particulate size distribution (Abakus Klotz laser diffraction spectrometry, and EOS Single Particle Extinction Scattering, SPES2; U. Bern2); and stable water isotopes (δ18O, δ2H; Picarro cavity ring-down spectrometry, CRDS; U. Bern2, BE-OI Isotope Consortium7-10,12). For the first time, we present sections of BE-OIC chemistry data, focusing on trace elements (ICP-QQQ-MS & ICP-OES) and major anions (FIC). In addition, the CFA campaign provided discrete liquid samples for single-particle trace elemental analysis (U. Bern2), organic analysis (U. Cambridge3, Ca’ Foscari U. Venice9&CNR-ISP10), δ34S (U. St. Andrews5), diatoms (BAS1), halogens (Ca’ Foscari U. Venice9 & CNR-ISP10), and tephra (BAS1, U. St. Andrews5 & Swansea U.6). Furthermore, discrete gas samples were collected for 81Kr dating (Heidelberg U.11).