Richmondian

Richmondian

[rich′mən·dē·ən]
(geology)
A North American stage of geologic time: Upper Ordovician (above Maysvillian, below Lower Silurian).
References in periodicals archive ?
put forward hypotheses for the deposition of the Oldenburg 'butter shale' in the Upper Ordovician (Katian; Richmondian) Waynesville Formation, USA.
However, without comprehensive statistical analyses of the taphocoenosis, the predatory origin of these borings cannot be excluded, as it has been suggested for some borings in Richmondian Onniella meeki (see Kaplan & Baumiller 2000).
The fauna is relatively undiagnostic, and may range in age from late Edenian into the Richmondian. The Plectodina-dominated biofacies association is indicative of open marine shelf conditions of moderate depth (Sweet and Bergstrom, 1984).
Strata assigned to the upper Katian (Cincinnatian: uppermost Maysvillian to lower Richmondian) Mount Auburn Member of the Grant Lake Formation in southwestern Ohio and its lateral equivalents, the Terrill Member of the Ashlock Formation in central Kentucky and the Straight Creek Member of the Grant Lake Limestone (sensu Schumacher et al.
There are over a dozen butter shale horizons in the Cincinnati Ordovician, and half of these occur in the Waynesville Formation (Richmondian), a 30 m succession of siliciclastic mudstones alternating with bundles of skeletal packand grainstone.
The Richmondian Invasion, a regional invasion event that introduced over 60 genera from five phyla into the Cincinnati, Ohio, USA region, occurred during the early Richmondian (late Katian) Age.
In the uppermost Richmondian Regional Stage (upper Katian Global Stage), just below the unconformity at the top of the Richmondian Stage, Bergstrom et al.
In this study, we examine a specific episode of interbasinal species invasion, the Richmondian Invasion, which is recorded in the Katian age strata of the Cincinnatian Series in the Cincinnati, USA region.
2), comprising the Upper Katian (Cincinnatian: upper Maysvillian-lower Richmondian of North American terminology) Grant Lake and Bull Fork formations (Fig.