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The Laurentide Ice Sheet was characterized by a dynamic polythermal base. However, important data and knowledge gaps have led to contrasting reconstructions in areas such as the Labrador Ice Divide. In this study, detailed fieldwork was conducted at the southeastern edge of a major landform boundary to resolve the relative ice flow chronology and constrain the evolution of the subglacial dynamics, including the migration and collapse of the Labrador Ice Divide. Surficial mapping and analysis of 94 outcrop‐scale ice flow indicators were used to develop a relative ice flow chronology. 10Be exposure ages were used with optical ages to confine the timing of deglaciation within the study area. Four phases of ice flow were identified. Flow 1 was a northeasterly ice flow preserved under non‐erosive subglacial conditions associated with the development of an ice divide. Flow 2 was a northwest ice flow, which we correlate to the Ungava Bay Ice Stream and led to a westward migration of the ice divide, preserving Flow 2 features and resulting in Flow 3's eastward‐trending indicators. Flow 4 is limited to sparse fine striations within and around the regional uplands. The new optical ages and 10Be exposure ages add to the regional geochronology dataset, which further constrains the timing of ice margin retreat in the area to around 8.0 ka. Geological Survey of Canada's Geo‐Mapping for Energy and Minerals II (GEM2) Program (2013–2020) Polar Continental Support Program under the Core Zone Surficial Activity (Hudson–Ungava Project) Northern Scientific Training Program (NSTP) Ontario Graduate Scholarship (OGS) fund Natural Science and Engineering Research Council (NSERC) of Canada Discovery Grant NSERC Research Tools and Instruments Grant Peer-review status unspecified Update citation details during checkdate report - AC

The distribution of basal drag zones (sticky spots) underneath palaeo-ice streams or lobes is largely unknown. We investigated the centre of the large (300 km long and up to 400 km wide) deglacial Hayes Lobe in NE Manitoba, Canada, by focusing on surficial till and its composition to get insights into dispersal patterns and their potential relationships to areas of basal drag. Subglacial bed roughness is a good criterion to identify areas of basal drag, but till composition may provide important insights across smoother beds. The onset zone of the Hayes Lobe overlies Palaeozoic Carbonate Platform rocks, whereas the majority of the lobe overlies the low-lying Canadian Shield. We show that, within a 3500-km2 central area of this lobe, calcareous detritus within the till has been transported over 100 km within subglacial environments of reduced ice-bed coupling and fast ice flow. Six per cent of samples (n = 782), however, outline 0.2 to 4 km wide spots with a dominantly local composition. The glacial history and composition indicate that the till within these spots contains high inheritance from a pre-Late Wisconsinan ice-flow phase, which we suggest was protected beneath sticky spots (low erosion, high strength) during transport of substantial calcareous detritus to the area. Furthermore, our findings show that local till spots are present within streamlined landforms, as well as till blankets or veneers over bedrock. This diverse geomorphology indicates that the process of drumlinization within the deglacial Hayes Lobe does not appear to have been responsible for significant sediment transport or deposition across the study area. The overall record thus indicates potentially complex spatiotemporal shifts between calcareous till deposition, sticky conditions, erosion and drumlinization – which supports the subglacial bed mosaic model.

Summary In the UK, drainage for agricultural reclamation during the 19th and 20th centuries is responsible for an alteration of the ecological and hydrological functioning of peatlands, in turn, affecting a whole suite of ecosystem services. Today, initiatives are in place throughout the UK to reinstate this eco-hydrological functioning by blocking drainage ditches. Effects on ecosystem services remain unclear, as does the overlapping impact of climate change on peatland recovery. This article uses a conceptual model to present the effects of restoration on ecosystem services, that is, water provision and quality, carbon storage, biodiversity, food and fibre provision and cultural services, both immediately after ditch blocking and in the few years post-restoration. The model is then applied in the context of Exmoor National Park, in South West England and used to perform a cost–benefit analysis of the restoration and monitoring programme, as these shallow peatlands are located in geographically marginal areas, and therefore more sensitive to climate change. Past research indicates that some processes tend to return progressively to their predisturbance state, but whether the complete recovery of peatlands to functioning mires occurs after restoration remains unclear, partly due to the difference between the temporal and spatial scale at which processes occur (i.e. up to decadal) and are monitored (typically a few years). Overall, on Exmoor, the long-term benefit of peatland restoration to some ecosystem services, such as a reduction in carbon losses and improvement of water storage and quality, has the potential to balance high financial investment. Synthesis and applications. Gaining a better understanding of the effects of peatland restoration on ecosystem services provided is essential to assess the potential value of restoration projects. Using the case of the shallow peatlands of Exmoor National Park, located in geographically marginal areas in the UK and therefore more vulnerable to the effects of climate change, we find that there is potential for both the value of carbon storage and water provision to offset the costs of restoration in the long-term. Our results from Exmoor can provide ecological analogues of impending change further north.

The net effect of ice-flow shifts resulting in the dilution or reworking of clasts on a single preserved till sheet is often unknown yet has major implications for palaeoglaciology and mineral exploration. Herein, we analyse variations in till clast lithologies from a single till sheet, within palimpsest-type Glacial Terrain Zones in NE Manitoba, Canada, to better understand sediment–landform relationships in this area of high landform inheritance. This near-ice-divide area is known to consist of a highly fragmented subglacial landscape, resulting from spatio-temporal variations in intensity of reworking and inheritance throughout multiple glacial events (subglacial bed mosaic). We show that a seemingly homogenous ‘Keewatin’ till sheet is composed of local (>15 km) and continental-scale (∼100-km-long carbonate train and 350–600 km long Dubawnt red erratic train) fan, irregular (amoeboid) or lobate palimpsest dispersal patterns. Local dispersal is more complex than the preserved local landform flowset(s) record, but appears consistent with the overall glacial history reconstructed from regional flowset and striation analyses. The resultant surface till is a spatial mosaic interpreted to reflect variable intensities in modification (overprinting) and preservation (inheritance) of a predominately pre-existing till sheet. A multi-faceted approach integrating till composition, regional landforms, ice-flow indicators, and stratigraphic knowledge is used to map relative spatio-temporal erosion/reworking intensity.

Ross, M., Lajeunesse, P. & Kosar, K. G. A. 2010: The subglacial record of northern Hudson Bay: insights into the Hudson Strait Ice Stream catchment. Boreas, 10.1111/j.1502-3885.2010.00176.x. ISSN 0300-9483. In this paper, we present new insights into the glacial dynamics and potential configuration of the Hudson Strait Ice Stream catchment in the northern Hudson Bay–western Hudson Strait region. Our reconstruction is based on new field observations and till compositional data from Southampton Island, remote sensing imagery and multibeam bathymetric data from the Hudson Bay sea floor, as well as on a re-examination of previously published data from this vast region. Our findings suggest that, during the late Quaternary, the HSIS catchment consisted of a number of ice-stream tributaries feeding a curvilinear trunk that potentially extended into western Hudson Bay. In contrast to previous interpretations, the occurrence of fluted bedrock hills, over-deepened basins, Dubawnt erratics and carbonaceous till on the islands at the head of Hudson Strait is taken to imply that cold-based conditions did not prevail on these islands. The upland area of Southampton Island and the surrounding channels played an important role in controlling the location of the main tributaries, with the higher central terrain forming a large inter-ice-stream zone lacking carbonate detritus. Coats Island contains abundant evidence of vigorous ice flow, such as mega-scale glacial lineations (MSGLs). MSGLs also occur on the sea floor southwest of Coats Island but the sea-floor imprint is highly discontinuous. Observations on the western Hudson Bay mainland show evidence of southeastward fast ice flow that is spatially consistent with the Dubawnt dispersal train. Despite the geomorphological discontinuities, this may indicate that the HSIS onset zone extended far inside the Laurentide Ice Sheet and across contrasting geological domains.

The analysis of the glacial landscape of southern Saskatchewan (Canada) through multiple data sets (e.g. digital elevation model, till compositional data) has revealed previously unrecognized subglacial sediment–landform assemblages. A southwest-trending corridor of mega-scale till lineations (Maskwa corridor) bounded on each side by hummocky terrain extends from the Canadian Shield to southwestern Saskatchewan. This landform assemblage is clearly cross-cut by a broad south to southeast trending corridor (Buffalo corridor) consisting of subparallel curvilinear till ridges. The carbonate content of the surface till is spatially consistent within these assemblages, suggesting a strong sediment–landform relationship. The two corridors are interpreted as the product of palaeo-ice streams. The Maskwa palaeo-ice stream flowed up the regional slope and across preglacial valleys, indicating it was thick and stable. Narrow dispersal trains extending across as well as down-glacier from the Athabasca Basin suggest that the Maskwa palaeo-ice stream extended far into the ice sheet across contrasting shield and platform terrains. In comparison, the Buffalo palaeo-ice stream was thinner and largely controlled by subglacial geology and topography. Its catchments were located at the Canadian Shield boundary and the system was oriented along-slope. It experienced lateral shifts and it was fed by a network of tributaries. The glacial dynamics shift from the Maskwa to the Buffalo system occurred at about 13.5 14C kyr BP. The Buffalo system later evolved into thin outlet lobes until final deglaciation of the area. The proposed model has implications for ice-sheet reconstruction and the assessment of till properties in the prairies and in similar terrains.

There are high aspirations for environmental water quality targets in the UK, but requirements for significant growth in agricultural production to meet both food security objectives and provide viable livelihoods for farmers make these hard to achieve. Significant water quality challenges are related to nutrients, pesticides, pharmaceuticals, pathogens, sediments and habitat alteration. To facilitate the challenges posed, there is a need for predictive, spatially-distributed models to be developed that encompass the key aspects of agriculture and water management in order to inform future policy and organisations with an interest in land management. Additionally, there needs to be recognition from policy makers that different solutions are needed in different agri-water systems and that it often takes many years or decades for policies to have a sustained water quality impact. Long-term support for research infrastructure and the scientific skills base is required to enable measurement and data analysis necessary to inform decision making. Farmers need clearly articulated information on the issues and potential solutions on which to make informed management decisions regarding water. There are existing solutions to some problems and this knowledge needs to be effectively disseminated with appropriate incentives for implementation to have maximum impact. Greater collaboration between researchers, industry and policy makers, with the necessary framework to deliver effective joint working, is urgently needed. There is also a need for a wider societal understanding of the land-water system and the various ways in which society pays (and might pay in the future) for the real value of water.