Carboniferous sand provenance in the Pennine Basin, UK: constraints from heavy mineral and detrital zircon age data

Heavy-mineral, mineral-chemical and zircon-age constraints on the provenance of Triassic sandstones from the Devon coast, southern Britain

“…Variscan granites are widespread in the Armorican Massif of northern France and equivalent parts of the Variscan mountain belt in central Europe (Tischendorf et al, 1995;Brown & Dallmeyer, 1996;Ballèvre, 2009;Tyrrell et al, 2012). These granites are known to have been available as a sediment source as early as the Late Carboniferous, on the basis of the presence of detrital zircons in Westphalian sandstones of the UK (Hallsworth et al, 2000;Morton et al, 2010), and on the basis of evidence for rapid exhumation of such granites in the Variscan mountain belt (Schulmann et al, 2002). The scarcity of Late Carboniferous and Early Permian zircons in the Devon coast succession suggests that the catchment area did not extend into regions of Armorica that include widespread Variscan granites, and therefore implies that the source was more proximal, probably in the English Channel and possibly extending into the Channel Islands, the La Hague peninsula and the northern Brittany coast, where Variscan granites are comparatively minor (Brun et al, 2001;Sansom et al, 2005).…”

Variscan sourcing of Westphalian (Pennsylvanian) sandstones in the Canonbie Coalfield, UK

“…If so, this would extend the known northward distribution of Variscan-derived Upper Carboniferous sediment, the previous record being the Dalton Rock (Bolsovian) near Sheffield, Yorkshire (Hallsworth et al 2000).…”

“…Derivation from the north or west can be categorically ruled out, since the zircon age structure in sample NJN100 contrasts strongly with that seen in northerly or westerly derived Carboniferous sandstones in the Pennine Basin. The zircon populations in northerly or westerly derived sandstones have Archaean, mid-Proterozoic and Silurian-Devonian elements, indicating that their source regions lay in parts of Laurentia-Baltica that were affected by the Caledonian orogeny (Hallsworth et al 2000).…”

“…However, during the Asturian, there is evidence that the Wales-Brabant High was breached (Besly, 1988), a view supported by the similarity between the petrographical character of the Halesowen and Canonbie Bridge Sandstone formations (north of the Wales-Brabant High) and the Pennant Sandstone Formation (south of the high), which suggests a common provenance for these sandstones. Hence, it is possible that sediment could have been introduced to the English Midlands and the Canonbie area from the Armorican Massif through the breached WalesBrabant High at this time (Hallsworth et al 2000). However, Sherlock, Jones & Jones (2000) argued that Bolsovian-Asturian lithic arenites in the Forest of Dean Basin (south of the Wales-Brabant High) were derived from the central European Variscides.…”

Idades U-Pb de zircão detríticos e suas implicações na proveniência de sedimentos da Formação Penedo, Bacia de Sergipe-Alagoas, NE Brasil

“…Para tanto, diversas técnicas podem ser aplicadas, tais como a identificação da composição dos plagioclásios detríticos em arenitos; a identificação dos tipos de maclas nos feldspatos ou tipos de grãos de quartzo e suas inclusões; a análise de minerais pesados; a análise geocronológica; o levantamento de paleocorrente; e a identificação de seixos e calhaus em arenitos conglomeráticos e conglomerados (Roback e Walker, 1995;Morton et al, 1996Morton et al, , 2005Sircombe, 1999Sircombe, , 2000Carwood e Nemchin, 2000;Hallsworth et al, 2000;Link et al, 2005;Nascimento et al, 2007;Araújo et al, 2012;Neves, 2015).…”