Gateway to the Paleobiology Database
Rhynie cherts (BMNH coll.) (Devonian of the United Kingdom)

Where: Scotland, United Kingdom (57.3° N, 2.9° W: paleocoordinates 22.4° S, 6.5° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Dryden Flags Formation, Pragian (412.3 - 409.1 Ma)

• The Rhynie and Windyfield cherts found at Rhynie, Aberdeenshire, Scotland, both occurring in the Dryden Flags Formation (Rice et al. 2002), represent the surface expression of a metaliferous hydrothermal system that was active in the Rhynie area during the early Devonian (Pragian: Rice et al. 1995, 2002).

Environment/lithology: pond; lithified, stromatolitic, black, blue chert

• The background setting was an alluvial plain set in a narrow half-graben basin with mainly overbank deposition on floodplains and in ephemeral lakes, with occasional sheetflood events sourced from the axial river system and basin margins (Trewin 1994, 2001). The cherts were deposited as subaerial siliceous sinters, although some beds represent the silicified contents of freshwater pools (Anderson & Trewin 2003; Trewin et al. 2003).
• Bluish black,microbially laminated chert and internally massive nodular chert, set within a matrix of silicified sandstone (Fig. 2). Internally, the nodular chert displays filamentous, coprolitic and clotted microscopic textures (sensu Anderson & Trewin 2003) and a mixed terrestrial and freshwater biota, indicating silicification of the organic contents of a small freshwater pool.

Size classes: mesofossils, microfossils

Preservation: permineralized, replaced with silica

Collected by Hirst; reposited in the BMNH

Collection methods: peel or thin section,

Primary reference: S. Hirst. 1923. On some arachnid remains from the Old Red Sandstone (Rhynie Chert Bed, Aberdeenshire). Annual Magazine of Natural History 9:455-474 [P. Gensel/M. Kotyk] more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 172777: authorized by Matthew Clapham, entered by Matthew Clapham on 22.08.2015

Creative Commons license: CC BY (attribution)