Stable Isotope ratios of black calcites, Elephant Moraine, East Antarctic Ice Sheet

Brief description

The dataset relates to the stable C and O isotope ratios of samples of calcites attributed to subglacial depositional processes in Antarctica. The samples were collected by G. Faure at a location known as “Elephant Moraine”. Thus, we do not actually know where the original site of deposition of the samples was, as they have been transported through glacial processes. Nevertheless, stable C and O isotope ratios of selected samples help to understand the original depositional environment.

The samples were selected from “black calcite”, whose age is older than 200,000 years (ca. 500,000 year), because of their fabric. This means that the sample consisted (under the optical microscope) of similar aggregates of crystals, so that we can exclude a “crystal-effect” on the dataset.

Stable carbon and oxygen isotope ratios of SPCC 3922, 13081 from Elephant Moraine measured by reacting carbonate powder samples (150–200 μg) with orthophosphoric acid reaction at 72 °C (Spötl and Vennemann, 2003) and analyzing the evolved CO2 by an automated GASBENCH II sample preparation attached to a Thermo Finnigan Delta Plus XP isotope ratio mass spectrometer (IRMS) at the Institute for Geological and Geochemical Research (IGGR, Budapest, Hungary). Raw measurements were calibrated using NBS-18 and NBS-19 calcite standards (provided by the International Atomic Energy Agency). Harding Iceland Spar (HIS; Landis, 1983), and the CO-8 standard calcite (provided by the International Atomic Energy Agency) were measured as unknowns in the course of this study (HIS: measured δ13C = –4.81 ±0.03‰, δ18O = –18.54 ±0.05‰, n=8; published δ13C = –4.8‰, δ18O = –18.56‰; CO-8 measured δ13C = –5.76 ±0.02‰, δ18O = –22.85 ±0.07‰, n=5; expected δ13C = –5.76‰, δ18O = –22.7‰). On the basis of deviations from expected compositions and measurement reproducibilities, the accuracy of δ13C values is estimated as better than ±0.1‰. However, the δ18O values of the studies samples fall well outside the standardized range, hence slightly larger uncertainties (0.1-0.3‰) should be considered.

Powders were drilled at 0.5 mm intervals for a total length of ca. 60 mm


Landis, G.P., 1983. Harding Iceland Spar: a new δ18O-δ13C carbonate standard for hydrothermal minerals. Isotope Geoscience 1, 91-94.
Spötl, C., Vennemann, T. W., 2003. Continuous−flow isotope ratio mass spectrometric analysis of carbonate minerals. Rapid Commun. Mass Spectrom. 17, 1004–1006.