Palaeontology, stratigraphy and sedimentology of the Kinderscoutian and Lower Marsdenian (Namurian) of North Staffordshire and adjacent areas

Abstract

The thicker-shelled goniatite fauna of the Kinderscoutian and the Marsdenian up to the R. bilingue s. s. marine band is described in detail. The lower part of the Kinderscoutian is almost completely fossiliferous and the goniatites are described from "horizons" rather than marine bands. Five marine bands have been identified in Rlb, and faunas from two marine bands noted in Rlc. The R. gracile, R. 0bilingue early form and R. bilingue s. s. marine bands are described from the Marsdenian. Identification of material from the Brund Boreholes confirms the succession deduced from field evidence, and a revision of the R. dubium subzone is suggested on the basis of palaeontological evidence from North Staffordshire.

As well as the faunal marker horizons, eight thin, kaolinised ash bands have been used in correlation of the succession. The existence of these bands and the establishment of the faunal succession has enabled the stratigraphy of the sandstones to be studied in detail.

The K-feldspathic lithofacies, derived from the north, is composed entirely of turbidites. It has been divided up into seven sublithofacies by the use of such characteristics as average bed thickness and sandstone: shale ratios. The K-feldspathic lithofacies is diachronous, making its first appearance in Rlc in the north of the area and R2b in the south. Rhythms superimposed on a megarhythm, or sandstone unit between two marine bands, have been recognised and described in detail from an R2a section.

The lowest Kinderscoutian protoquartzite units known are in the upper part of Rla in the south of the area. Representatives of this lithofacies as deltaic deposits are known at various horizons up to R2b in the south, but the lithofacies occurs more rarely in the north, extending as tongues of turbidites from the deltaic area in Rlb and Ric.

The differing rates of sedimentation and environments of deposition of the protoquartzites and K-feldspathic sandstones on occasion influence the thickness of the marine bands and their faunas. Variations are noted in the distribution of these faunas in relationship to the sediments, particularly within the R. gracile sequence.