Encyclopedia of Geobiology

2011 Edition
| Editors: Joachim Reitner, Volker Thiel

Reduction Spheroids

  • Beda A. Hofmann
Reference work entry
DOI: https://doi.org/10.1007/978-1-4020-9212-1_212

Synonyms

Bleaching haloes; Fish eyes; Radioactive concretions; Radioactive nodules; Reduction mottling; Reduction spots; Reduktionshöfe

Definition

Reduction spheroids are small-scale (diameter: few millimeters to maximum about 20 cm) spheroidal bleached features in red-bed sediments characterized by the absence of hematite and often containing a mineralized core (center, Figure 1). Reduction spheroids result from local chemical reduction of ferric iron and other elements. Host rocks are marine and continental red beds and, more rarely, altered, hematite-stained crystalline rocks. Reduction spheroids have been described from many occurrences in red beds of widely variable age worldwide: Proterozoic of Canada (Tanton, 1948); Cambro-Silurian marine red beds of the NE USA (Beutner and Charles, 1985); Devonian continental red beds of Scotland (Parnell, 1985); Carboniferous continental red beds of New Brunswick and Nova Scotia, Canada (Dyck and McCorkell, 1983); Permian continental red beds...
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Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Beda A. Hofmann
    • 1
  1. 1.Earth Science DepartmentNatural History Museum BernBernSwitzerland