Stratigraphic evolution of provenance characteristics in Westphalian sandstones of the Yorkshire Coalfield

Abstract

SUMMARY A combined study of heavy minerals and palaeocurrents shows that three main fluvial systems transported sediment to the Pennine Basin during Namurian and Westphalian times. The first, which brought a garnet-rich monazitic heavy mineral suite from the north, peaked in the Namurian and diminished through the Langsettian. The second flowed from the west, bringing heavy mineral suites with low garnet, low monazite and variable amounts of chrome spinel. It started in the late Namurian, replaced the first system in the Langsettian, and dominated thereafter until it was itself replaced in the late Duckmantian by the third system. This brought a garnetiferous heavy mineral suite with both monazite and chrome spinel from the E or SE and continued to the top of the preserved sequence, in the late Bolsovian. The first sourceland lay to the north, perhaps between Laurentia and Baltica, and included high grade metasediments or charnockites and granites. The second sourceland lay to the west and included mature, pre-existing clastic sediments of Devonian and possibly Lower Palaeozoic age. Ultramafic rocks such as ophiolites, possibly associated with Lower Palaeozoic ocean closure, were periodically exposed there. The third sourceland lay to the south, probably within the uplifting Variscan orogenic belt. It included low to moderate grade metasediments, high-grade gneisses, granites and ultramafic rocks.

Geological controls on the sulphur content of coal seams in the Northumberland Coalfield, Northeast England

“…Palaeocurrent and petrographic data indicate that the Northumberland Coal Measures were supplied with sediment from an extensive hinterland, ca. 250 km to the northeast, throughout the Silesian Glover et al, 1996;Leng et al, 1999;Hallsworth and Chisholm, 2000) (Fig. 2), albeit with contributions from local uplands distributed around the compass (Haszeldine, 1984;Turner and Smith, 1995;O'Mara and Turner, 1999) (Fig.…”

Warwickshire Group (Pennsylvanian) red-beds of the Canonbie Coalfield, England–Scotland border, and their regional palaeogeographical implications

“…These samples were also analysed for their heavy mineral assemblages in order to compare them with the extensive published dataset (Hallsworth, 1992;Hallsworth & Chisholm, 2000;Morton, Claoúe-Long & Hallsworth, 2001;Morton, Hallsworth & Moscariello, 2005). Heavy mineral separations from the 63-125 μm fraction were analysed petrographically using the technique of Morton & Hallsworth (1994, and using the ribbon counting method of Galehouse (1971) for 200 non-opaque heavy mineral grains (Table 3).…”

Sequence stratigraphy of the upper Millstone Grit (Yeadonian, Namurian), North Wales

“…These thickness variations are comparable to those documented on the East Midlands Shelf, across rifted Lower Carboniferous half-grabens (Church and Gawthorpe 1994;Fraser and Gawthorpe 2003). However, the palaeocurrents and petrography of the lower Gwespyr Sandstone Formation and Aqueduct Grit support the influx of westerly-derived sediment into the Central Province Basin during the Yeadonian (Collinson and Banks 1975;McLean and Chisholm 1996;Hallsworth and Chisholm 2000), possibly in response to tectonic activity in sediment-source hinterland areas (Hampson 1998). …”

“…Feldspathic sandstones characterize the Gwespyr Sandstone Formation (47-63% quartz and 29-40% feldspar in samples A-H, Table 2) and Aqueduct Grit (68-80% quartz and 14-18% feldspar in samples J-K, Table 2), although much of the feldspar has been degraded to kaolinite. Approximately half of the quartz grains are polycrystalline (Table 2) and many have undulose extinction, suggesting a granitic or metasedimentary source (Carnozzi 1993) that is consistent with recycling from the Precambrian continental-shield to the north ( Figure 2; Gilligan 1920;Glover et al 1996;Leng et al 1999; and/or Lower Palaeozoic siliciclastic sediments to the west (Figure 2; Collinson and Banks 1975;McLean and Chisholm 1996;Hallsworth and Chisholm 2000). In the absence of heavy mineral and detrital zircon age data or palynological data (McLean and Chisholm 1996), sediments derived from these two source areas cannot be distinguished.…”

“…Most sediment was derived from northward-lying uplands in Laurentia and Baltica (Figure 2), which consisted of Precambrian continental-shield and Caledonide fold-belt material (Sorby 1859;Gilligan 1920;Glover et al 1996;Leng et al 1999;Tyrrell et al 2006). A second, westerly source comprising reworked, Lower Palaeozoic siliciclastic sediments was important in the Yeadonian (Figure 2; Collinson and Banks 1975;McLean and Chisholm 1996;Hallsworth and Chisholm 2000). The Wales-Brabant Massif also formed a local sediment source along the southern margin of the basin (Figure 2), consisting of Precambrian to Lower Palaeozoic metasedimentary, metavolcanic and sedimentary rocks (e.g.…”