University Of Tasmania

File(s) under permanent embargo

Subarctic weathering of mineral wastes provides a sink for atmospheric CO2

journal contribution
posted on 2023-05-19, 23:01 authored by Wilson, SA, Dipple, GM, Power, IM, Shaun BarkerShaun Barker, Fallon, SJ, Southam, G
The mineral waste from some mines has the capacity to trap and store CO2 within secondary carbonate minerals via the process of silicate weathering. Nesquehonite [MgCO3·3H2O] forms by weathering of Mg-silicate minerals in kimberlitic mine tailings at the Diavik Diamond Mine, Northwest Territories, Canada. Less abundant Na- and Ca-carbonate minerals precipitate from sewage treatment effluent deposited in the tailings storage facility. Radiocarbon and stable carbon and oxygen isotopes are used to assess the ability of mine tailings to trap and store modern CO2 within these minerals in the arid, subarctic climate at Diavik. Stable isotopic data cannot always uniquely identify the source of carbon stored within minerals in this setting; however, radiocarbon isotopic data provide a reliable quantitative estimate for sequestration of modern carbon. At least 89% of the carbon trapped within secondary carbonate minerals at Diavik is derived from a modern source, either by direct uptake of atmospheric CO2 or indirect uptake though the biosphere. Silicate weathering at Diavik is trapping 102-114 g C/m2/y within nesquehonite, which corresponds to a 2 orders of magnitude increase over the background rate of CO2 uptake predicted from arctic and subarctic river catchment data.


Publication title

Environmental Science and Technology










School of Natural Sciences


Amer Chemical Soc

Place of publication

1155 16Th St, Nw, Washington, USA, Dc, 20036

Rights statement

Copyright 2011 American Chemical Society

Repository Status

  • Restricted

Socio-economic Objectives

Climate change mitigation strategies

Usage metrics

    University Of Tasmania