Work

Banded iron formation to iron ore: A record of the evolution of Earth environments?

Year: 2012

Type: article

Abstract: Banded iron formations (BIF) are the protolith to most of the world’s largest iron ore deposits. Previous hypogene genetic models for Paleoproterozoic “Lake Superior” BIF-hosted deposits invoke upwards, down-temperature flow of basinal brines via complex silica and carbonate precipitation/dissolution processes. Such models are challenged by the necessary SiO2 removal. Thermodynamic and mass balance constraints are used to refine conceptual models of the formation of BIF-hosted iron-ore. These constraints, plus existing isotope and halogen ratio evidence, are consistent with removal of silica by down- or up-directed infiltration of high-pH hypersaline brines, with or without a contribution from basinal brines. The proposed link to surface environments suggest that Paleoproterozoic BIF-ore upgrade may provide a record of a critical time in the evolution of the Earth’s biosphere and hydrosphere.

Source: Geology

DOI: 10.1130/g33244.1

Authors: K.A. Evans, T.C. McCuaig, D. Leach, T. Angerer, S.G. Hagemann

Institutions: Curtin University, The University of Western Australia, ARC Centre of Excellence for Core to Crust Fluid Systems

Language: English

Topic: Paleontology and Stratigraphy of Fossils

Subfield: Paleontology

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: green

Funders: Curtin University of Technology, Australian Research Council

OpenAlex ID: W2000618267