Abstract The Namurian and Westphalian sequences from the onshore well Scaftworth-B2, located in the Gainsborough Trough, central England, have been analysed for whole-rock inorganic geochemical data via inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (MS). The changes within key elements, and elemental ratios, results in a chemostratigraphic zonation scheme consisting of eight chemostratigraphic sequences and 13 chemostratigraphic packages, providing the type zonation for the Bowland Shale and overlying formations. Mineralogical data are provided by whole rock X-ray diffraction (XRD) and are used to calibrate the mineral modelling in order to generate a modelled mineral log for the study well. Furthermore, the modelled mineralogy is then used to calculate a relative brittleness for the samples, which can then be collaborated with traditional rock properties data at a later date. Elemental data can also be used to model the relative abundance of detrital quartz and biogenic silica; while total silicon is detected by ICP, biogenic silica is not detected by XRD owing to its amorphous nature. Enrichment factors calculated from the inorganic elemental data suggest that the sediment was deposited in an unrestricted marine setting, which experienced periods of anoxia.

Abstract The general tendency for sediment supply to deep water to be relatively high during eustatic fall and lowstand, and relatively low during rise and highstand, is recognized in the sequence-stratigraphy literature. Much less is known about the cumulative effect of repeated eustatic cycles on net deep-water sediment delivery. Here we investigate the net effect of offshore sediment delivery during a complete eustatic cycle, which we term sediment pumping , and the possibility of cumulative sediment pumping if repeated eustatic cycles increase the net delivery of sediment to deep water averaged over several cycles. We measure sediment pumping in terms of net offshore delivery after one or more complete eustatic and associated cycles relative to delivery in the absence of cycles. Combining data from a quasi-2D laboratory experiment and a 2D geometric model, we find that net sediment pumping over isolated and superimposed base-level cycles of variable period varies from somewhat negative to strongly positive, depending on (1) time period of imposed base-level cycle, (2) sense of rotation of the spatial subsidence pattern, and (3) the phase of sediment supply relative to eustatic variation. A relatively short-period base-level cycle (i.e., period less than the basin equilibrium time) increases net pumping (relative to the constant base-level reference case) whereas a relatively longperiod cycle yields no or even negative net pumping. Short-period base-level cycles superimposed on a long-period cycle produce a strong net offshore sediment pumping. Other factors being equal, base-level cycles with basin subsidence cause substantially greater net pumping in backtilted basins than in foretilted ones. When sediment supply varies over a base-level cycle, pumping is maximized when the sediment-supply maximum occurs during eustatic falling stage or lowstand. External Controls on Deep-Water Depositional Systems SEPM Special Publication No. 92 (CD version), Copyright © 2009 SEPM (Society for Sedimentary Geology), ISBN 978-1-56576-200-8, p. 41–56.