Calcareous nannofossils from the Santa Marta Formation (Upper Cretaceous), northern James Ross Island,Antarctic Peninsula

This study reports on the most stratigraphically extensive nannofloras yet recovered from the Lachman Crags Member of the Santa Marta Formation, James Ross Island, Antarctic Peninsula. The productive samples are dated as early Campanian. These ages are in accord with those provided by ammonites, foraminifera, ostracods and radiolarians from the same locality. The consistent and relatively abundant presence of Gephyrobiscutum diabolum throughout the productive part of the section, a species that has previously only been documented from the Falkland Plateau, extends its geographic distribution to higher latitudes, at least to the Antarctic Peninsula area.     

Microtopographical and hydrophysical controls on subsurface flow and solute transport: A continuous solute release experiment in a subarctic bog

Resource extraction and transportation activities in subarctic Canada can result in the unintentional release of contaminants into the surrounding peatlands. In the event of a release, a thorough understanding of solute transport within the saturated zone is necessary to predict plume fate and the potential impacts on peatland ecosystems. To better characterize contaminant transport in these systems, approximately 13,000 L/day of sodium chloride tracer (200 mg/L) was released into a bog in the James Bay Lowland. The tracer was pumped into a fully penetrating well (1.5 m) between July 5 and August 18, 2015. Horizontal and vertical plume development was measured via in situ specific conductance and water table depth from an adaptive monitoring network. Over the spill period, the bulk of the plume travelled a lateral distance of 100 m in the direction of the slight regional groundwater and topographical slope. The plume shape was irregular and followed the hollows, indicating preferential flow paths due to the site microtopography. Saturated transport of the tracer occurred primarily at ~25 cm below ground surface (bgs), and at a discontinuous high hydraulic conductivity layer ~125 cm bgs due to a complex and heterogeneous vertical hydraulic conductivity profile. Plume measurement was confounded by a large amount of precipitation (233 mm over the study period) that temporarily diluted the tracer in the highly conductive upper peat layer. Longitudinal solute advection can be approximated using local water table information (i.e., depth and gradient); microtopography; and meteorological conditions. Vertical distribution of solute within the peat profile is far more complex due to the heterogeneous subsurface; characterization would be aided by a detailed understanding of the site‐specific peat profile; the degree of decomposition; and the type of contaminant (e.g., reactive/nonreactive). The results of this research highlight the difficulty of tracking a contaminant spill in bogs and provide a benchmark for the characterization of the short‐term fate of a plume in these complex systems.     

Experimental hydrological forcing to illustrate water flow processes of a subarctic ladder fen peatland

Large peatland complexes dominate the landscape of the James Bay Lowland in subarctic Ontario, Canada. However, there is not a thorough understanding of the hydrological processes occurring in these important systems, particularly how ladder fens connect large domed bogs to the aquatic ecosystems that drain the peatland complex. Ladder fens consist of a pool‐rib topography where flow downgradient is controlled by the peat ribs. Within the ribs, low‐lying preferential flow paths typically enhance the transmission of water, whereas the elevated ridge microforms impede water flow to downgradient aquatic ecosystems. To assess the hydrological connectivity, we study the role of the water table, peat transmissivity, and microtopography of a small ladder fen for 3 summers (2013–2015) in the James Bay Lowland. The system was manipulated with a sustained hydrological forcing (water addition) to the upslope boundary of the fen during 2014 (38 m³/day) and 2015 (30 m³/day). There was an exponential increase in transmissivity towards the peat surface due to extremely high‐hydraulic conductivities within the upper few centimeters of the peat deposit. At the maximum water table, the saturated hydraulic conductivity of the 0.1 m layer of peat below the water table varied depending on peat microtopography (preferential flow paths = 42–598 m/day and ridges = 16–52 m/day), resulting in high‐hydrological connectivity periods. Furthermore, during 2015, there was an abnormally large amount of precipitation (300 mm vs. long‐term average ~ 100 mm) that resulted in complete surface water connectivity of the site. This caused rapid movement of water from the head of system to the outlet (~15 hr) and runoff ratios >1, compared to low‐water table periods (runoff ratio ~ 0.05). This study highlights the profound importance of the transmissivity–water table feedback mechanism in ladder fens, on controlling the water retention and drainage of large peatland complexes.     

Timing of the Northern Prince Gustav Ice Stream retreat and the deglaciation of northern James Ross Island,Antarctic Peninsula during the last glacial–interglacial transition

The Northern Prince Gustav Ice Stream located in Prince Gustav Channel, drained the northeastern portion of the Antarctic Peninsula Ice Sheet during the last glacial maximum. Here we present a chronology of its retreat based on in situ produced cosmogenic ¹⁰Be from erratic boulders at Cape Lachman, northern James Ross Island. Schmidt hammer testing was adopted to assess the weathering state of erratic boulders in order to better interpret excess cosmogenic ¹⁰Be from cumulative periods of pre-exposure or earlier release from the glacier. The weighted mean exposure age of five boulders based on Schmidt hammer data is 12.9 ± 1.2 ka representing the beginning of the deglaciation of lower-lying areas (< 60 m a.s.l.) of the northern James Ross Island, when Northern Prince Gustav Ice Stream split from the remaining James Ross Island ice cover. This age represents the minimum age of the transition from grounded ice stream to floating ice shelf in the middle continental shelf areas of the northern Prince Gustav Channel. The remaining ice cover located at higher elevations of northern James Ross Island retreated during the early Holocene due to gradual decay of terrestrial ice and increase of equilibrium line altitude. Schmidt hammer R-values are inversely correlated with ¹⁰Be exposure ages and could be used as a proxy for exposure history of individual granite boulders in this region and favour the hypothesis of earlier release of boulders with excessive ¹⁰Be concentrations from glacier directly at this site. These data provide evidences for an earlier deglaciation of northern James Ross Island when compared with other recently presented cosmogenic nuclide based deglaciation chronologies, but this timing coincides with rapid increase of atmospheric temperature in this marginal part of Antarctica.     

'Water all around, you cannot even drink': the scaling of water in James Bay/Eeyou Istchee

Since the 1970s, the reconfiguration of the La Grande River into a hydroelectric complex has radically altered the James Bay region and brought about new scales of identification and exchanges between peoples and places. Through this process, water emerged as an increasingly globalized entity while at the same time being captured as a local icon of cultural identification both by the Eeyouch (Eastern James Bay Cree) and the Québécois. Using an historical and discursive approach, this paper explores the intersection between the rescaling of water and the rescaling of the nation for each community. The removal of the river from the traditional places of production of the Eeyouch to redirect it into electricity-generating facilities that put every drop of water to work has dramatically changed the meaning of 'here' and 'there'– as well as 'us' and 'them'– for the Eeyouch and the Québécois, indicating that a theory of the differentiation and hierarchical organization of space needs to inform collaborative efforts toward environmental management in the region.     

REVISITING THE TOPIA ROAD: WALKING IN THE FOOTSTEPS OF WEST AND PARSONS*

ABSTRACT. In 1940, Berkeley graduate‐student geographers Robert West and James Parsons traveled to Mexico's Sierra Madre Occidental to retrace the Topia Road, colonial Mexico's main trans‐Sierran trail linking isolated mountain mining hamlets with the Pacific Coast and the world beyond, a journey chronicled in a 1941 Geographical Review article. Almost sixty years later, we document an attempt to retrace West and Parsons's route. Based on field observations, interviews with local informants, replication of Parsons's photographs, and his field notes, we evaluate landscape alteration in what West and Parsons referred to as some of the most isolated settlements in Mexico. We assess changes in the still‐remote communities along the route in terms of three influences: mining, migration, and drug trafficking.     

The Bulger Case: A Spatial Story

Abstract

This paper contributes to debates in the emerging field of cinematic cartography () by exploring the ways in which strategies of digital cinemapping can function as tools of critical spatial practice and urban wayfinding. More specifically, the paper considers the scope for digital video technologies to reshape, contest and ‘ground’ spaces of urban representation and the ‘spatial stories’ these bring into play. Basing my analysis on the mediation of the events surrounding the abduction and murder of the 2-year-old boy James Bulger in 1993, I examine the case as a constellation of spatial narratives within which I weave my own spatial story in the form of a video mapping of the abduction route (in Bootle near Liverpool) and the responses and issues this further mediation has provoked. Methodological reflections on the map-making process are discussed alongside narratives generated by the video on YouTube. The paper argues that, by adopting practices of wayfinding, and by being critically attentive to the ways in which film and video-making practices are also spatial practices, moving image cartographies can provide insights into lived and embedded spaces of memory, and the hidden or muted spatial stories to which they play host.     

Arcellaceans (thecamoebians): new tools for monitoring long- and short-term changes in lake bottom acidity

 James Lake, northeastern Ontario, Canada, has been impacted by the dumping of waste rock from a pyrite mine. High levels of Fe, Al and SO₄, and low pH (2.0–5.5) are recorded in the lake. Lake configuration and current direction result in contaminated areas being restricted to the southwestern portion of the lake. Near neutral pH and low metal levels are recorded elsewhere. Analysis of arcellacean faunas from the lake indicate that one species, Arcella vulgaris, is able to thrive in even the most hostile areas of the lake. The absence of other arcellaceans indicative of contaminated substrates in higher pH lakes, such as centropyxids and Difflugia protaeiformis strains, suggests that pH is the dominant control on the distribution of this assemblage. Analysis of arcellaceans from a core at the site indicates that contamination and acidification (pH values <5.5) problems in James Lake have existed for at least 1300 years, clearly predating mining activity. Prior to that time high proportions of centropyxid species indicate less acid conditions (pH>5.5) prevailed, but a stressed environment existed for several thousand years. The recognition that Arcellacean faunas can now be used to characterize industrially, and naturally contaminated environments of both low and high pH, provides an important new paleolimnological tool. Received: 6 October 1998 · Accepted: 23 February 1999     

Microstructural analyses of a Middle Pliocene till from the James Bay Lowlands,Canada—evidence of “potential” fast ice streaming

Sediment from the Attawapiskat area near James Bay, Northern Ontario was sampled for micromorphological analyses. The sediment is a glacial diamicton (till) of subglacial origin. The till contains entrained and scavenged sediments of proglacial and/or subglacial glaciofluvial/glaciolacustrine origin from a subglacial deforming layer that was emplaced due to both stress reduction and/or porewater dissipation. Evidence of porewater escape, clay translocation and other microstructures all point to emplacement under active subglacial bed deformation. The limited number of edge to edge (ee) grain crushing events, however, point to lower stress levels than might anticipated under a thin fast ice lobe of the James Bay during the Middle Pliocene. Microstructures of Pleistocene tills were quantitatively compared with the Attawapiskat till and the limited number of ee events at Attawapiskat further highlighted that grain to grain contact was curtailed possibly due to high till porosity, high porewater pressures and low strain rates or alternatively due to a high clay matrix component reducing grain crushing contact events. It is suggested that this Middle Pliocene till may be indicative of sediments emplaced under ice lobe surging conditions or fast ice stream subglacial environments. This proposal has significant implications for the glaciodynamics of this part of the Middle Pliocene James Bay lobe. This research highlights a crucial link between subglacial conditions, till microstructural analyses and glaciodynamics.