Comparative palynostratigraphy of the early Arnsbergian (Namurian) sequences between Great Britain and northwest China

Abstract The proposed stratotype section for the Pendleian–Arnsbergian stage boundary, located at Slieve Anierin in Ireland, contains diagnostic ammonoids but the sediments are thermally too mature to permit the recovery of palynomorphs. Detailed investigations undertaken on a prospective parastratotype section at Mirk Fell Gill in northern England however offers the prospect for the precise palynostratigraphic calibration of this boundary. Limited ammonoid and conodont data are available to support these conclusions. Previous work in the British Isles has equated this stage boundary with that between the Bellispores nitidus–Reticulatisporites carnosus (NC) and Stenozonotriletes triangulus–Rotaspora knoxi (TK) miospore zones of Owens et al. [Proc. Yorks. Geol. Soc. 41 (1977) 381–398] and Clayton et al. [Meded. Rijks Geol. Dienst 29 (1977) 1–71]. Data from the Mirk Fell Gill section will be compared with datasets from deposits of similar age in China to assess the degree of change in palaeobiogeographical composition across the Euramerican landmass.