Quantitative palynological analysis of the E2a and E2b goniatite biozones (Arnsbergian, Mississippian) in mudstones from the Southern Pennine Basin (U.K.)

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We performed a quantitative palynological analysis of Arnsbergian (Namurian, Late Mississippian) mudstone intervals, potentially prospective for unconventional hydrocarbons. While many palynological studies exist on these stratigraphic intervals in the Widmerpool Gulf and the Edale Basin (sub-basins of the Pennine Basin), very few studies perform full statistical analyses. Using the Carsington Dam Reconstruction C3 (Carsington DRC3, Widmerpool Gulf) and the Karenight-1 (Edale Basin) boreholes, we show that the combination of quantitative palynological data and detrended correspondence analysis (DCA) can aid biozonation and additionally, provide paleoecological constraints to the Arnsbergian mudrocks. The studied interval in Carsington DRC3 was assigned to the TK miospore biozone and a hitherto undescribed peak in the fresh water alga Botryococcus was recorded. Using relative abundances of hinterland species, mainly from the genus Florinites, both boreholes could be correlated and a more confident assignment of the TK miospore biozone covering an interval containing goniatite biozone E2b in Karenight-1 was achieved. The techniques used in the current study should be especially valuable for assessing borehole materials where the recovery of macrofossils, like goniatites used as the main biostratigraphic tool in the Namurian, can be very low. Future studies should focus on the same stratigraphic interval from different sub-basins of the Pennine Basin to further assess the applicability of quantitative palynological analysis combined with DCA as a stratigraphic tool for potentially prospective mudstones.