Linked Data Explorerhttp://worldcat.org/entity/work/id/2298595
Pyritic cone-in-cone concretions
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http://schema.org/about
- http://id.loc.gov/authorities/subjects/sh85030750
- http://id.worldcat.org/fast/940727
- http://id.worldcat.org/fast/874418
- http://id.loc.gov/authorities/subjects/sh85109339
- http://id.worldcat.org/fast/1240052
- http://id.loc.gov/authorities/subjects/sh85054106
- http://id.worldcat.org/fast/1084661
- http://id.worldcat.org/fast/1353968
- http://experiment.worldcat.org/entity/work/data/2298595#Event/from_280_to_310_million_years_ago
http://schema.org/alternateName
- "Cone-in-cone concretions"
http://schema.org/description
- "A number of pyritic cone-in-cone concretions from Middle Pennsylvanian black shales of Indiana and Illinois are described. These are the only occurrences of typical cone-in-cone structure composed of pyrite that are known to the author, other than those described from Cambrian and Ordovician shales of the Oslo region, Norway. The Indiana concretions have a core of earthy, phosphatic material, probably coprolitic; the Illinois specimen is an isolated cone. Both occurrences have the typical fabric and structure of the usual calcitic (dolomitic) cone-in-cone. The latter is diagenetic in origin and has formed as a direct consequence of fibrous growth in semi-consolidated sediments. Because of this, the striking similarity of structure between the pyritic and carbonate types, and the contrasts between the crystal habits of calcite and pyrite, the pyritic cone-in-cone is interpreted as a pyrite replacement of original carbonate cone-in-cone concretions."