Palynological assemblages recovered from siltstone and fine-sandstone lithologies of the Greenmoor Rock (Langsettian, Late Carboniferous) in the Sheffield district, England, contain low numbers (1–2%) of reworked miospores of Devonian (Givetian-Frasnian). Tournaisian, and late Viséan-early Namurian age. Acritarchs of Ordovician-Devonian age are also present. The maturation level of the reworked palynomorphs is no greater than that of the associated Langsettian material implying that the Lower Palaeozoic acritarchs are derived from non-metamorphic (i.e. extra-Caledonide) terranes. The reworked palynomorphs may be derived from Langsettian erosion of Ordovician-Namurian sediments or may indicate multiple phases of reworking, being derived from erosion of Devonian-Namurian sediments which contained reworked Lower Palaeozoic acritarchs. The composition of the reworked assemblages indicates that the Greenmoor Rock is made up of sediment derived from two possible areas: (1) the Wales-Brabant Massif which was partly emergent during Langsettian times, or (2) Lower Palaeozoic and/or Devonian rocks of the Mid-North Sea High.