The susceptibility of glacigenic deposits to liquefaction under seismic loading conditions: a case study relating to nuclear site characterization in West Cumbria

Abstract

The susceptibility of glacigenic deposits to liquefaction under seismic loading conditions : a case study relating to nuclear site characterization in West Cumbria.', Proceedings of the Yorkshire Geological Society., 62 . pp. 116-132.

High-resolution 3D geological modelling of heterogeneity in poorly exposed glacial deposits using sedimentary and glaciotectonic architectural element analysis: a case example from Sellafield in west Cumbria, UK

“…Subsequent research in the region has generally developed and established this account of events (Evans, et al, 2005;Roberts, et al, 2007;Thomas & Chiverrell, 2007;Ballantyne, et al, 2009;Stone, et al, 2010;Clark, et al, 2012;Livingstone, et al, 2012;Chiverrell, et al, 2013;Cross, et al, 2018;Smith, et al, 2020). A radically different interpretation has been offered by Eyles & McCabe (1989), who attempted to reconcile much of the evidence described here into their controversial model of glaciomarine ice sheet retreat caused by a rapid marine ingress into a glacio-isostatically depressed Irish Sea basin.…”

“…M A N U S C R I P T Units may also be spatially limited for purely depositional reasons: for example, channels within a braided river system change course, resulting in repeated, stacked, amalgamated fluvial sequences (Medici, et al, 2015). Furthermore, in formerly glaciated regions such as West Cumbria, many units within glacigenic sequences have been affected by subglacial and glaciotectonic processes at various scales, resulting in localized thickening or removal, structural repetition, deformation, postdepositional subglacial injection of sediment by hydrofracturing, shrink-and-swell architectures and the development of widespread, gently undulating, sharp bounding surfaces (Nirex, 1997a-e;Busby & Merritt, 1999;Merritt & Auton, 2000;Williams, et al, 2001;Smith & Merritt, 2008;Cross, et al, 2018;Smith, et al, 2020).…”

“…Our procedure first involves the definition of a sedimentary and glaciotectonic architectural element framework based on prior knowledge of the Quaternary sequence and placed within a land-system classification (cf Evans & Benn, 2021a;Cross, et al, 2018). A new portfolio of generic geometries for erosional bounding surfaces of architectural elements/lithofacies are then developed, which are used to aid confident correlation between boreholes.…”

“…The first stage of architectural element analysis is typically an assessment of all the lithofacies present within a study area (Medici, et al, 2015). Considering the complex glacial sequence in West Cumbria, particularly with respect to till units that locally include other interbedded deposits, Cross, et al, (2018) proposed a landsystem-based, process-form model for the Sellafield area that relates glaciation style and dynamics. This approach provides a broad template for interpreting glacigenic landformsediment or 'facies' associations (Evans, 2017).…”

“…Although, from observations made in the field, we have separated architectural elements possessing 'ice contact' from 'ice marginal' architectures (sensu Slomka & Eyles, 2013 -although we use the term 'proglacial' rather than 'ice marginal' since the latter must logically include ice contact architectures). The base of the ice sheet was probably underlain by a deformable bed of water-saturated sediment during the glacial readvances that affected the district (Cross, et al, 2018), which would have aided rapid ice flow and the deposition of subglacial traction till and glaciotectonite (sensu Benn & Evans, 1996;Evans, et al, 2006;Evans, 2018).…”