Palynostratigraphy of the Upper Carboniferous Langesttian-Duckmantian Stage Boundary in Britain

Abstract

A critique of palynostratigraphic zonation schemes associated with the Langsettian-Duckmantian Stage boundary shows that, at high levels of stratigraphic resolution, most criteria used as palynological proxies for the position of the boundary are unsuitable. Most importantly, in the Duckmantian stratotype section the highest stratigraphic occurrence of the index species Schulzospora rara is above (rather than below or within) the Vanderbeckei Marine Band, the base of which defines the Duckmantian Stage. A cored section through the boundary in southern North Sea well 44/22-1 displays comparable microfloral distributions. While data are as yet too sparse to provide detailed answers, the findings have implications for understanding how marine flooding events affected Carboniferous microfloral evolution and extinction. Ultimately this influences how microfloral biozone boundaries relate to the regional European Upper Carboniferous stage boundaries, which are largely defined in relation to strata deposited during marine flooding events similar to that associated with the Langsettian-Duckmantian boundary. The miospore genus Sinuspores Artüz is emended, and two new taxa are described: Gondisporites bulboides sp. nov. and Hymenospora murdochensis sp. nov.

Late Moscovian terrestrial biotas and palaeoenvironments of Variscan Euramerica

“…Langsettian to early Bolsovian strata consist of grey, fluvio-lacustrine Coal Measures (Cowan, 1989;Collinson et al, 1993;Cole et al, 1995) with occasional marine horizons (e.g. McLean et al, 2004). Langsettian and early Duckmantian sequences are comparable to the sandstone-prone Pennine Coal Measures of the Durham Coalfield (Haszeldine & Anderton, 1980;Fielding, 1984b), passing upwards (into mid Duckmantian to mid Bolsovian age) and laterally southwards (Cameron, 1993;Quirk, 1993) into finer-grained facies comparable to the mudstone-prone Pennine Coal Measures of the East Midlands, onshore UK (Rothwell & Quinn, 1987;Fraser & Gawthorpe, 1990).…”

“…The Langsettian to Bolsovian coal measures facies are equivalent to the Pennine Coal Measures Group of onshore UK (Waters et al, 2007) and have been calibrated throughout by miospore biozones (e.g. McLean et al, 2004). The Bolsovian and Asturian red-bed sequences are equivalent to the Warwickshire Group of onshore UK (Waters et al, 2007).…”

A STRUCTURAL REINTERPRETATION OF THE ENIGMATIC CARBONIFEROUS MIOSPORE PTERORETIS FELIX & BURBRIDGE 1961 EMEND. NOV.

“…In UK southern North Sea Quadrants 43, 44, 48 and 49, Pteroretis primum is known from the Upper Arnsbergian Millstone Grit Formation (Miospore Biozone N3a of McLean et al, 2005) to the Lower Bolsovian Upper Cleaver Member (Miospore Biozone W5b of McLean et al, 2005). It is most common in strata close to the Aegiranum Marine Band (Lower and Upper Cleaver members).…”