Carbonate Depositional Environments, Sequence Stratigraphy and Exceptional Skeletal Preservation in the Much Wenlock Limestone Formation (Silurian) of Dudley, England

Abstract

The Much Wenlock Limestone Formation of the Dudley inliers, West Midlands, contains one of the world's richest and most exquisitely preserved Silurian marine biotas. However, for most museum specimens, little is known of their exact provenance and mode of preservation. Detailed comparisons between outcrops and museum collections allow the identification of five faunal-lithological associations and numerous horizons of exceptional skeletal preservation. The associations are interpreted as a series of transient carbonate mid-platform environments extending from below storm wave-base to above fair-weather wave-base. Erosive surfaces, condensed sections, flooding surfaces and the stacking patterns of genetically related bed-sets (parasequences) have allowed the formation to be interpreted as a single third-order sequence stratigraphic cycle of sea-level change. The articulated preservation of taxa such as pelmatozoan echinoderms and trilobites can be attributed to either rapid burial by obrution deposits close to fair-weather wave-base or smothering by storm sequestered muds in slightly deeperwater settings. Such intervals of exceptional preservation are commonly associated with flooding surfaces, presumably reflecting reduced likelihood of reworking once rapid burial had taken place.

Harnessing stratigraphic bias at the section scale: conodont diversity in the Homerian (Silurian) of the Midland Platform, England

“…Lithofacies in the Wenlock of the study areas have been previously characterized by Butler (), Phipps & Reeve (), Shergold & Bassett (), Oliver (), Ratcliffe & Thomas (), Ray & Thomas (), and Ray et al . (, ).…”

“…The section (Fig. ; SO 9454 9164; 52°31′21.01″ N, 2°04′53.73″ W) is located in Castle Mill Basin in Dudley (Ray & Thomas ; Worton ). It exposes the uppermost part of the Coalbrookdale Formation and part of the Lower Quarried Limestone Member.…”

“…). A detailed, parasequence‐level sequence‐stratigraphy framework has been developed for multiple late Wenlock sections across the platform and allows for correlation between onshore–offshore and shore‐parallel sections (Ray & Thomas ; Ray et al . , ).…”

U-Pb (zircon) age constraints on the timing and duration of Wenlock (Silurian) paleocommunity collapse and recovery during the "Big Crisis"

“…If one were to consider pure lithostratigraphy to be the best chronostratigraphic tool to correlate strata from Ludlow to Dudley, WNH15 would be placed at a position in the uppermost part of the Homerian Stage of the Wenlock Series (just below the base of the Lower Elton Formation). Based upon recent parasequence analysis of the West Midlands (e.g., Ray and Thomas, 2007;Ray et al 2010), WNH15 occurs within parasequence 12 (PS12), and by parasequence correlation to the base Ludlow GSSP (Fig. 6) on November 28, 2012 gsabulletin.gsapubs.org Downloaded from excursion nearly marks the end of the Homerian Epoch, but new data help clarify this chemostratigraphic relationship.…”

“…The site is under the supervision of Natural England and the Dudley Metropolitan Borough Council, Directorate of the Urban Environment, and sampling permission requests can be made to the Site Manager and Keeper of Geology at the Dudley Museum and Art Gallery. Recent investigations of the classical Homerian localities around Wenlock Edge and the West Midlands, England, have signifi cantly improved correlations between the various facies present in the area (e.g., Ray and Thomas, 2007;Ray et al, 2010) and have also identifi ed and named a series of stratigraphically persistent bentonites throughout the Homerian strata of the region (Ray, 2007;Ray et al, 2011c). The global boundary stratotype section for the base of the Ludlow Series (Pitch Coppice Quarry) is located roughly 50 km west-southwest of Wren's Nest Hill (Fig.…”