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TitreMineral resource assessment of the shallowest bedrock and overburden, Laurentian Channel, Newfoundland: potential marine protected area
AuteurKing, E L
SourceCommission géologique du Canada, Dossier public 6969, 2012, 27 pages, (Accès ouvert)
ÉditeurRessources naturelles Canada
Documentdossier public
Mediaen ligne; numérique
ProvinceRégion extracotière de l'est
Lat/Long OENS -60.0000 -56.5000 47.5000 44.5000
Sujetspotentiel minier; bassins sédimentaires; analyses du bassin; charbon; tills; dépôts glaciaires; boues; sediments; sables; graviers; épaisseur de la couverture meuble; stratigraphie; géologie marine; minéraux industriels; Quaternaire; Cénozoïque
Illustrationslocation maps; cross-sections; stratigraphic columns; profiles
ProgrammeEnvironnement et ressources minérales et énergétiques (ERME)
Diffusé2012 03 14
Résumé(disponible en anglais seulement)
A proposed Marine Protected Area (MPA) has been identified for a large portion of the eastern flank of the Laurentian Channel by the Department of Fisheries and Oceans (DFO) and has been designated as what is referred to as an Area of Interest (AOI) leading to a minerals assessment by Natural Resources Canada (NRCan). This report will examine the shallowest bedrock and overburden within the AOI. It complements a full assessment of deeper resources, mainly hydrocarbons, which is presented under a separate report. New and previously published maps, cross sections, and sample analyses showing the distribution of the bedrock subcrop pattern, the locally thick Quaternary overburden, and the surficial geology are presented with the aim to document the geological conditions more completely than previous compilations. However, conclusions regarding potential resources are derived much more from inferences than from direct sampling. Carboniferous bedrock in the Sydney Basin has been shown to be coal-bearing across a very expansive area. However, given ephemeral economic viability of onshore and offshore coal mining in the Sydney Basin, these potential resources, despite very poor understanding of amounts, could only be important in a different energy/economic environment than presently foreseen. The Sydney Basin may be a significant producer of gas, given widespread occurrence of gas-formed pockmarks at the seabed and the very expansive basin (12 000 km2 in the DFO AOI and 60 000 km2 otherwise). Tills are voluminous, 75 m thick on average and locally hundreds of metres thick, with a volume estimate of 1250 km3 of (mainly) till within the Department of Fisheries and Oceans area of interest boundaries. The numerous stacked tills result from the latest and retreat deposition phases of an ice stream and are broadly distributed in combination with relatively old tills that subcrop beneath surficial mud. Tills have mostly not been sampled and mineral assessment is by inference. Given the dispersive nature of the subglacial process and the successive erosion of older tills, together with the dominantly mud- rich character, probability of a resource is considered low. Muds overlying the till comprise up to 200 km3 in the AOI, are better sampled but the analyzed suite of minerals suggest there is little that is unique or of economic value. Aggregate is practically nonexistent in the area as the AOI is consistently below the latest low-stand of sea level where, on the adjacent bank, sea-level rise resulted in large sand-dominated bodies. Geohazards are largely restricted to seismicity, and its sideeffects, and potential natural gas escape at the seabed, but both processes have been more active in early post-glacial times than at present.