BGS Rock Classification Scheme

Microoncoid-ironstone - A type of ironstone composed dominantly of microoncoids. British Geological Survey Research Report RR/99/03, section 5.2, table 15 and fig. 9. Synonym: iron-microoncolite.

Code FEMONC
Description Microoncoid-ironstone - A type of ironstone composed dominantly of microoncoids. British Geological Survey Research Report RR/99/03, section 5.2, table 15 and fig. 9. Synonym: iron-microoncolite.
Qualifiers No qualifiers currently exist.
Definition Sedimentary rock (>15wt% iron), with particles >50% iron-bearing minerals (15wt% iron). Allochem dominantly as micro-oncoids, <2mm coated grains with irregular partially overlapping laminae, biogenic structures may be present. Particle size not defined.
Linked data http://data.bgs.ac.uk/id/EarthMaterialClass/RockName/FEMONC

CAVEAT

"Thumbnail" definitions attached to some of the table entries are an interim attempt to provide simple short descriptions of the "unqualified" rock types presented within the BGS Rock Classification Scheme. Every effort has been made to ensure accuracy and consistency but minor contradictions or omissions might be present. The BGS welcomes any feedback pointing out such minor imperfections and/or providing constructive comment and suggestions for improvement of the definitions. In the first instance such feedback should be directed to Dr Tim McCormick.