Eastern Ellesmere Island Research Articles

Lower Cambrian (Series 2) small shelly fossils from along Nares Strait (Nunavut and Greenland; Laurentia)

Three small assemblages of lower Cambrian (Cambrian Series 2, Stage 4) small shelly fossils are described from Laurentian strata astride Nares Strait. The fauna from the Humboldt Formation of Daugaard-Jensen Land, North Greenland, is derived from inner shelf sediments deposited on the stable craton of the Inglefield Land High. Fossils from Judge Daly Promontory, eastern Ellesmere Island, Nunavut, occur in strata of the Cambrian Ellesmere Group (Kane Basin Formation) that have been structurally juxtaposed against older strata; they were originally assigned to the Kennedy Channel Formation, which is now considered to be of Neoproterozoic age. A similar fauna from offshore environments of the Aftenstjernesø Formation in northern Nyeboe Land, North Greenland, reflects the regional structural and sedimentological continuity with the Canadian Cambrian succession. Pojetaia robsonae sp. nov. is described from Judge Daly Promontory.

Glacier changes over the past 144 years at Alexandra Fiord, Ellesmere Island, Canada

AbstractIn this study, we use aerial photographs, satellite imagery and field observations to quantify changes in the area, terminus length, snowline elevation and surface elevation of eight glaciers in the Alexandra Fiord region, eastern Ellesmere Island, between 1959 and 2019. Comparisons to written and pictorial descriptions from the British Arctic Expedition extend the record of change in terminus position and surface elevation to 1875 for Twin Glacier. Glacier area at Alexandra Fiord decreased by a total of 15.77 ± 0.65 km2(11.77 ± 0.49%) between 1959 and 2019, the mean end of summer snowline increased in elevation by 360 ± 84 m (8 ± 2 m a−1) between 1974 and 2019, and the glaciers thinned at an average rate of 0.60 ± 0.06 m a−1between 2001 and 2018. Annual rates of terminus retreat were ~3–5 times higher over the period 1974–2019 compared to 1875–1974, and rates of thinning were ~2–3 times higher over 2001–18 compared to 1875–2001. Our results are consistent with rates of change determined for other glaciers of similar size on Ellesmere Island, and with accelerated rates of ice loss coincident with regional increases in air temperature of ~1.5°C since the early 1980s.

Abundance of Atlantic walrus in Western Nares Strait, Baffin Bay Stock, during summer

Atlantic walruses (Odobenus rosmarus rosmarus) belonging to the Baffin Bay subpopulation occur year round in the North Water polynya (NOW) between NW Greenland and eastern Ellesmere Island (Canada). They are hunted for subsistence purposes by residents of the Qaanaaq area (NW Greenland) bordering the NOW to the east and by Canadian Inuit at the entrance to Jones Sound in Nunavut. During the open-water period NW Greenland is virtually devoid of walruses which concentrate along eastern and southern Ellesmere Island at this time of the year. To determine the abundance of walruses in the NOW area, aerial surveys were conducted in August of 1999, 2008, and 2009. In July 2009, nine satellite-linked transmitters were deployed in nearby Kane Basin. Surveys on 9 and 20 August 2009 along eastern Ellesmere Island were the most extensive and were augmented with concomitant data on haul-out and at water surface activity from three (1 F, 2 M) of the nine tags that were still functioning. We therefore focus on the 2009 surveys. Walruses were observed on the ice and in water primarily in Buchanan Bay and Princess Marie Bay where the remaining functional tags were located. The Minimum Counted population (MCP) was 571 on 20 August. Adjusting the MCP of walruses on ice for those not hauled out, the estimate of abundance of walruses in the Baffin Bay stock was 1,251(CV=1.00, 95% CI = 1,226) when adjusted by the proportion of tags ‘dry’ at the time of the survey and 1,249 (CV=1.12, 95% CI = 1,370) when adjusted by the average time tags were dry. The surveys did not cover all potential walrus summering habitat along eastern Ellesmere Island and are negatively biased to an unknown degree.

An isotopic investigation of mercury accumulation in terrestrial food webs adjacent to an Arctic seabird colony

At Cape Vera (Devon Island, Nunavut, Canada), a seabird colony of northern fulmars (Fulmarus glacialis) congregates and releases nutrients through the deposition of guano to the coastal terrestrial environment, thus creating nutrient-fertilized habitats important to insects, birds, and mammals. Here we determined whether mercury was similarly enriched in various terrestrial food web components in this High Arctic coastal ecosystem due to seabird inputs. Stable isotopes (δ15N, δ13C) were used to identify trophic linkages and possible routes of contaminant transfer in the food web. Values of δ15N were significantly higher in lichens and certain plants collected closer to the bird colony, demonstrating a gradient of seabird influence, and were higher at Cape Vera than our reference site at Cape Herschel, on eastern Ellesmere Island, an area relatively unaffected by seabirds. In contrast, δ13C showed little variation among terrestrial species, suggesting minimal influence by seabirds. Concentrations of total mercury (THg) in primary producers and phyto/zooplankton were not significantly correlated with distance from the seabird colony or δ15N values, and were similar to other taxa from the High Arctic. Our results provide novel data on THg in several Arctic taxa where concentrations have not been reported previously. Moreover, the analyses indicate that δ15N is significantly enriched in the adjacent environment by guano fertilization, but our study was unable to show an enrichment of THg and δ13C in the terrestrial food web near the seabird colony.

Tracking Long-Term Environmental Changes in Arctic Lakes and Ponds: A Paleolimnological Perspective

Rock Basin Lake, Baird Inlet (east-central Ellesmere Island, Nunavut, Canadian High Arctic) was the site of the first detailed paleolimnological study from the circumpolar region, which used diatom and chrysophyte microfossils to track past climatic change. Photo: John P. Smol, August 1987. H IGH-LATITUDE REGIONS have repeatedly been identified as important reference areas for environmental change research, as they are especially sensitive to even small climatic changes and are often the first to show signs of environmental shifts. Moreover, climatic changes occurring at high latitudes have profound effects on other regions. Unfortunately, long-term monitoring data are generally lacking for most regions, and this is especially true for the Arctic. Without these data, it is difficult to determine whether environmental conditions are changing, and if so, to specify the magnitude and direction of change. Fortunately, a variety of natural archives of environmental change (e.g., ice cores) can be used to reconstruct these missing data sets. One rapidly emerging area of research in the Arctic is paleolimnology, which is the science of reconstructing past lake and pond histories from the proxy data contained in sediment profiles (Smol, 2002). As lakes represent a common feature of most Arctic regions, paleolimnological techniques have now been applied to a wide variety of research questions (Pienitz et al., 2004). Dated sediment cores typically archive a very rich history of past limnological conditions, based on indicators such as fossil algae (especially diatoms and chrysophytes) and invertebrates (such as Cladocera and aquatic insect remains), as well as a suite of physical and chemical indicators, such as metals and contaminants (Smol, 2002). My Arctic limnology and paleolimnology research program began in 1983, when Dr. Weston Blake Jr., now an emeritus scientist at the Geological Survey of Canada, invited me to join his field crew at Cape Herschel on eastern Ellesmere Island. I published an early paper (part of my PhD dissertation) arguing that fluctuating lake-ice conditions (which are closely related to climatic variables) exerted a strong control on lake biota, and hence on the bioindicators preserved in lake sediments. The 1983 field season was the start of a lifelong interest in the limnology and paleoecology of Arctic lakes. In September 1984, I was hired as an assistant professor at Queen’s University, where Marianne Douglas, now a professor in the Department of Geology at the University of Toronto and holder of a Tier 1 Canada Research Chair in Global Change, was among my first cohort of students. We have been collaborating on polar research ever since. For over 20 years, we have been using both limnological and paleolimnological techniques to track a variety of environmental trends throughout the Arctic. I co-direct the

A statistical technique for determining the source area of glacially transported granite erratics in the Queen Elizabeth Islands, Nunavut

This paper develops a technique that utilizes spatial and compositional trends in granite erratics distributed across the eastern and northwestern Queen Elizabeth Islands to discriminate between glacial dispersal trains originating from the Precambrian Shield of Ellesmere Island and the Canadian mainland. The distribution of glacially transported granite erratics in the eastern and northwestern Queen Elizabeth Islands defines a coherent pattern of regional dispersal from the Precambrian Shield of eastern Ellesmere Island. Principal components and cluster analyses demonstrate that most erratics within this dispersal train cluster within the same compositional group. Other members of this group represent outcrops on eastern Ellesmere Island, which define the locations of possible source areas. However, other compositional groups, which are unique to outcrops on the mainland, are absent from this dispersal train. Collectively, these spatial and compositional trends suggest that granite erratics on southwest Ellesmere, Amund Ringnes, and Meighen islands occur within a single dispersal train that resulted from the westward expansion of the Innuitian Ice Sheet from the Precambrian Shield of eastern Ellesmere Island. This technique may determine what differences, if any, exist among the composition of granite erratics deposited by the westward expansion of the Innuitian Ice Sheet across the Queen Elizabeth Islands and those deposited by the northward expansion of the Laurentide Ice Sheet. Any such differences may be useful in determining whether granite erratics of presently unknown provenance elsewhere in the Queen Elizabeth Islands are of Laurentide or Innuitian origin.

Late Wisconsinan buildup and wastage of the Innuitian Ice Sheet across southern Ellesmere Island, Nunavut

During the Late Wisconsinan, a precursor of the Prince of Wales Icefield, southern Ellesmere Island, formed a prodigious ice divide of the Innuitian Ice Sheet. Initial buildup occurred after 19 ka BP, when the icefield advanced west (inland) across Makinson Inlet from margins similar to present. Subsequent reversal of flow to the east required ice divide migration to the west onto a plateau that is largely ice-free today. From this divide, a trunk glacier flowed eastward through Makinson Inlet to join the Smith Sound Ice Stream en route to nothern Baffin Bay. Westward flow from this divide filled Baumann Fiord, depositing a granite dispersal train that extends a further 600 km across the archipelago to the polar continental shelf. Deglaciation of most of Makinson Inlet occurred catastrophically at ~9.3 ka BP, forming a calving bay that thinned the Innuitian divide, thereby triggering deglaciation of most of Baumann Fiord by 8.5 ka BP. Ninety14C dates on Holocene shells and driftwood constrain deglacial isochrones and postglacial emergence curves on opposite sides of the former Innuitian divide. Isobases drawn on the 8 ka BP shoreline rise northwest towards Eureka Sound, the axis of maximum former ice thickness. Ice margins on Ellesmere Island were similar to present from ~50–19 ka BP (spanning marine isotope stages 3 and 2). However, significant regional variation in ice extent during this interval is recorded by ice rafting from the Laurentide Ice Sheet into Baffin Bay. Later buildup of the Innuitian Ice Sheet occurred during the low global sea level that defines the last glacial maximum (18 ka BP). We also suggest that the Innuitian Ice Sheet was influenced by the buttressing and subsequent removal of the Greenland Ice Sheet along eastern Ellesmere Island.

The glacial and sea-level history of Darling Peninsula, eastern Ellesmere Island

The glacial history of Darling Peninsula is recorded by meltwater channels and lateral moraines deposited by local ice that extended seaward of the present coast during the last glacial maximum. Above these moraines, shelly till and erratics of both Greenland and Ellesmere Island prove nance record more extensive ice of unknown age. At the time of this more extensive ice cover, Ellesmere Island ice displaced Greenland ice from many parts of this coastline, as shown by the widespread absence of Greenland erratics and shelly tills above Holocene marine limit. The chronology of deglaciation is based on 14 C dates obtained on marine shells collected from either ice-contact deltas or raised beaches close to marine limit (79-88 m asl). Deglaciation began at least 7.5 ka BP and the distribution of ice on the peninsula was similar to present conditions by 6.0 ka BP. The reconstruction of the sea level history of Darling Peninsula contributes to the reconstruction of regional isobases drawn on 7.5 ka BP shorelines which locally reach 80-90 m asl.

Chronology of the last recession of the Greenland Ice Sheet

AbstractA new deglaciation chronology for the ice‐free parts of Greenland, the continental shelf and eastern Ellesmere Island (Canada) is proposed. The chronology is based on a new compilation of all published radiocarbon dates from Greenland, and includes crucial new material from southern, northeastern and northwestern Greenland. Although each date provides only a minimum age for the local deglaciation, some of the dates come from species that indicate ice‐proximal glaciomarine conditions, and thus may be connected with the actual ice recession. In addition to shell dates, dates from marine algae, lake sediments, peat, terrestrial plants and driftwood also are included. Only offshore and in the far south have secure late‐glacial sediments been found. Other previous reports of late‐glacial sediments (older than 11.5 cal. kyr BP) from onshore parts of Greenland need to be confirmed. Most of the present ice‐free parts of Greenland and Nares Strait between Greenland and Ellesmere Island were not deglaciated until the early Holocene. Copyright © 2002 John Wiley & Sons, Ltd.

Mystery cairns on Washington Irving Island

AbstractIn 1875, members of the British Arctic Expedition under the command of George S. Nares discovered two ancient-looking stone cairns on Washington Irving Island at the entrance to Dobbin Bay, eastern Ellesmere Island, Nunavut, Canada. At least one of these cairns was destroyed by the expedition members to construct their own cairn. The possibility that these cairns were built by Norse voyagers to Kane Basin is supported by the large number of Norse artifacts recovered from Thule culture Inuit sites in the Bache Peninsula region just south of Washington Irving Island. Surveys of the island have identified scattered boulders marking the location of the cairns, but the question of the builders' identity still remains a mystery.

Coalescent Greenland and Innuitian ice during the Last Glacial Maximum: revising the Quaternary of the Canadian High Arctic

This paper constitutes a fundamental revision of the author’s earlier research and resolves a long-standing debate concerning the late Quaternary history of the Canadian High Arctic, supporting its inundation by glaciers during the Last Glacial Maximum (LGM). A transect along east Ellesmere Island demonstrates that ice advanced northward and southward along the axis of Nares Strait during the late Wisconsinan, debouching from a central saddle in Kane Basin. The configuration of Ellesmere Island and Greenland ice is based on moraines, meltwater channels and erratics. The youngest AMS 14C date obtained on shelly till suggests ice buildup after 19 ka BP whereas many other dates are younger than 30 ka BP. Furthermore, the lowest (youngest) detectable amino acid ratios on shells from till postdate the Robeson aminozone (>70 ka BP) and are separated from Holocene ratios by a narrow gap wholly consistent with the occupation of the strait by late Wisconsinan ice. Re-entry of the sea throughout Nares Strait is shown by a series of paleogeographic maps based on geomorphic evidence and radiocarbon dates on shells associated with marine limit. Deglaciation at the north end of the strait occurred by 10.1 ka BP and, at the south end, by 9.0 ka BP. Nares Strait may still have been blocked by ice north of Kane Basin at 8 ka BP, however; by 7.5 ka BP it provided an unobstructed seaway from the Arctic Ocean to Baffin Bay. The prominent ice margins within the fiords of eastern Ellesmere Island, previously considered to mark the last ice limit, record regional stabilization of land-based ice after breakup of preceding marine-based margins. Other implications of this study are: that ice buildup occurred post-30 ka BP (and possibly post-19 ka BP) during an interval widely assumed to be constrained by severe aridity in the high arctic; and that coalescent Greenland and Ellesmere Island ice during the LGM promoted thickening of the eastern Ellesmere Island ice divide, causing enhanced westward flow across the island to Eureka Sound. Sizeable postglacial emergence (80–120 m) on eastern Ellesmere Island is associated with the retreat of thick ice (⩾1 km) from the strait. Greater emergence in Eureka Sound, which extends southward into the central arctic islands, confirms the previously proposed axis of the Innuitian Ice Sheet. Further clarification of the extent, geometry, and retreat of the Innuitian Ice Sheet will provide new opportunities for glaciological and geophysical modelling, and help to identify late Quaternary sediment sources for the Arctic Ocean and Baffin Bay.

Drainage system behaviour of a High-Arctic polythermal glacier

AbstractMeasurements made at John Evans Glacier, eastern Ellesmere Island, Nunavut, Canada in 1994 and 1996 provide new insight into the internal hydrology of polythermal glaciers. During the early part of each melt season, supraglacial waters enter the glacier via a crevasse field about 4 km from the terminus and are stored in a subglacial reservoir. Release of the water from the reservoir occurs initially via an artesian fountain on the glacier surface and by upwelling of waters through subglacial sediments at the terminus (event1). Channelization of the subglacial waters then occurs and water is discharged as an outburst flood (event 2), which releases a considerably larger volume of water than event 1. Thus, drainage of the subglacial reservoir follows a cyclical pattern in which discharge oscillations increase in amplitude over time. The cycle may end with complete reservoir drainage. The total volume of water released was much greater in 1994 than in 1996, primarily because the 1994 melt season was longer and warmer than the 1996 season. Interannual differences in the form of the outflow hydrographs, and in the extent and timing of connections between the subglacial reservoir and marginal melt streams, are linked to variations in the size and rate of growth of the subglacial reservoir. This hydrological behaviour may have important implications for the dynamics of polythermal glaciers.

Glacier dynamics and paleoclimatic change during the last glaciation of eastern Ellesmere Island, Canada

A 300 km transect along the east coast of Ellesmere Island fills a major gap in the late Quaternary data base of the Canadian High Arctic. The last glacial maximum (LGM) is marked by prominent moraines and meltwater channels that terminate within 30 km of modern ice margins. Shells in glaciomarine deposits, collected beyond the LGM, indicate deglaciation by more extensive ice prior to 35 ka BP. More than 60 14C dates from glaciomarine sediments provide a chronology for past ice dynamics during the LGM. To the north, while many areas remained ice free due to severe aridity, several glaciers remained in contact with the sea until 7.1 ka BP. Farther south, most glaciers reached the coast and significantly infilled several fiords. This southward increase in glacier extent is due to larger glacial catchment basins and increased precipitation towards storm tracks in northern Baffin Bay. The earliest dates on deglaciation along the transect range from 8.1 to 7.7 ka BP. Initial retreat was controlled by the extent of the marine-based ice margins, which were destabilized by calving. Once landward of the sea, many glaciers stabilized until ~6.5 ka BP. Considerable interfiord variability in glacier dynamics is apparent. A paleoclimatic model is proposed linking past glacier activity in the Canadian High Arctic with the available ice core record. Greenland ice cores show that colder intervals, with depleted δ18O, were associated with reduced precipitation and storminess, which may have constrained ice buildup prior to ~15 ka BP. In contrast, the abrupt rise in δ18O after ~15 ka signals the onset of regional warming associated with increased storminess and precipitation (up to 200%). This may have occasioned a late buildup of High Arctic glaciers, which remained close to the last ice limit well into the Holocene.

Ella Bay Formation: Early Cambrian shelf differentiation in the Franklinian basin, central eastern Ellesmere Island, Arctic Canada

Strata of the Lower Cambrian (Atdabanian) Ella Bay Formation reflect progradation and exposure of a rimmed carbonate platform, subject to intermittent introduction of siliciclastic material from an inshore coastal sand belt or fluviodeltaic source. Initial rapid progradation of platformal carbonates was related to late rift subsidence. Stabilization of depositional sites of oolitic and stromatolitic platform marginal carbonates during middle and late Ella Bay times reflects the earliest phase of differential subsidence of the platform and deep-water basin within the Franklinian mobile belt. Carbonate strata landward of the rim accumulated in a protected shelf setting that was for the most part below effective storm wave base. Towards the end of Ella Bay times, the outer rim became emergent as a result of differential rotation along listric faults as the continental margin began to subside in response to early sea-floor spreading. Dissolution of carbonates along the outer rim during this phase led to the development of distinctive breccia-conglomerates as cave and karst fill. Carbonate production in the lagoon became highly restricted as siliciclastics derived from the inshore clastic belt flooded the area. The pronounced change in style between the Ella Bay Formation and overling clastics of the Ellesmere Group, which consists of a thick sequence of northwesterly prograding clastic wedges, may reflect a change to more rapid subsidence as the ocean began to spread. The local unconformity between the Ella Bay Formation and the Ellesmere Group is thus interpreted as a breakup unconformity.

Kennedy Channel Formation: key to the early history of the Franklinian continental margin, central eastern Ellesmere Island, Arctic Canada

The Franklinian sequence in the Canadian Arctic Islands may have been initiated by rifting in Late Proterozoic or Early Cambrian times. Unfortunately, no record of this early phase of basin evolution is exposed; the oldest known strata are weakly metamorphosed mudstones, limestones, and sandstones of the Kennedy Channel Formation. Although these have previously been considered late Precambrian in age, the presence of minor trilobite and brachiopod debris indicates an Early Cambrian age, possibly corresponding to a pre-Olenellus trilobite zone. Strata of the Kennedy Channel Formation reflect repeated progradation of shallow-water facies into a slowly subsiding basin that developed in response to subsidence at a late stage of rift development along the Franklinian shelf margin. The first two cycles involve storm- and tide-influenced clastics derived from the Precambrian Shield to the southeast, whereas the third and fourth cycles involve progradation of carbonate ramp and rimmed platform facies. The contact with overlying dolostones of the Ella Bay Formation represents a depositional and diagenetic facies boundary and not an unconformity.

Organic maturity of Late Cretaceous and Tertiary coal measures, Canadian Arctic Archipelago

Maastrichtian and Lower Tertiary strata of the Eureka Sound Formation are widespread in the Canadian Arctic Archipelago and include major resources of lignite, subbituminous and high-volatile bituminous coal. The level of organic maturity of the strata for the most part reflects pre-orogenic (pre-Late Eocene-Miocene) depths of burial and thus helps define Early Tertiary depositional patterns. In the Remus Basin, in the eastern Canadian Archipelago, over 90 seams of coal occur ranging in rank from lignite (0.15% R 0 max) to high-volatile bituminous (0.70% R 0 max). The maturity values at the base of the Eureka Sound Formation, in conjunction with measured maturation gradients, indicate a maximum paleothickness of 4500 m and outline a basin with well defined eastern, western and southern margins. On the bases of numerical modeling, the maturation gradients are interpreted to reflect paleogeothermal gradients up to 55°C/km in the eastern part of the basin and of about 20°C/km in the western part. Elsewhere in the Canadian Arctic Archipelago the level of organic maturity of the Eureka Sound Formation varies from 0.15% R 0 max to 0.70% R 0 max. Maturation gradients measured from Meighen Island in the Strand Fiord Basin and from Melville Island in the southern part of the West Sverdrup Basin are about 0.10 log R 0 max/km, and when compared to numerical models suggest paleogeothermal gradients on the order of 15°C/km. At Meighen Island the paleodepth of burial of the Eureka Sound Formation may have been up to 6000 m. As a first approximation, the Melville Island gradient is considered representative of West Sverdrup and Banks Basin. Using this gradients, a paleodepth of burial of 3000 m is calculated for central West Sverdrup Basin and 4000 m for the southern part. In Banks Basin the paleodepth of burial is estimated to be on the order of 4000 m. Maturity values obtained from the Lake Hazen and Judge Dally Basins, Eclipse Trough and Somerset, Devon and Cornwallis Islands and at Bache Peninsula on eastern Ellesmere Island cannot be readily interpreted in terms of paleodepth of burial. No measured sections are thick or complete enough to establish maturation gradients, and the Tertiary history of these areas is only poorly known. The low paleogeothernal gradients calculated from Meighen Island, Melville Island and from the western part of the Remus Basin (15–20°C/km) are considered to reflect low heat flow or rapid Tertiary sedimentation and uplift such that an equilibrium geothermal gradient may never have existed. The higher maturation gradients and interpreted paleogeothermal gradients in the eastern Remus Basin are considered to be the product of higher heat flow on eastern Ellesmere Island. Anomalously high levels of maturity obtained along the Stolz Fault and adjacent Strand Fiord on Axel Heiberg Island are attributed to the thermal effects of evaporite diapirs.

Reconstruction of the Glacial Ice Covers of Greenland and the Canadian Arctic Islands by Three-Dimensional, Perfectly Plastic Ice-Sheet Modelling

A three-dimensional perfectly plastic ice-sheet model, developed for determining the surface elevations and the flow pattern of an ice sheet with given bottom topography and ice-margin positions, is applied to the reconstruction of the glacial ice covers of Greenland and the Canadian Arctic islands. In the northern regions, two different reconstructions have been performed with ice margins along the present 600 and 200 m sea-depth contours, respectively. In central Greenland, the ice margin is considered to be at the outermost ice-margin deposits on the coastal shelf to the west, and at the present 200 m sea-depth contour to the east.The main conclusions to be drawn from the reconstructions are: (1). The flow pattern of the glacial ice cover of Greenland shows a great resemblance to the present one, the central ice divide being displaced less than 50 km from its present position and being no more than 200 m higher than today. (2). The main ice divide of the ice sheet covering the Canadian Arctic islands (the Innuitian ice sheet) was located over the highlands of eastern Ellesmere Island with local domes positioned over the present ice caps, indicating that even the deep ice of Wisconsin age in these ice caps is of local origin. This is also the case for the Devon Island ice cap. (3). Even in the not very likely case of a rather extensive glacial ice cover in north-west Greenland, the ice-flow pattern upstream of the Camp Century deep drill site would not have changed radically compared to the present flow pattern. Thus it is concluded that even advanced ice margins in late-Wisconsin time could at most have resulted in an elevation of the deposition site of the late-Wisconsin ice at Camp Century 600 m higher than at present. The consequences of this conclusion are discussed.

Reconstruction of the Glacial Ice Covers of Greenland and the Canadian Arctic Islands by Three-Dimensional, Perfectly Plastic Ice-Sheet Modelling

A three-dimensional perfectly plastic ice-sheet model, developed for determining the surface elevations and the flow pattern of an ice sheet with given bottom topography and ice-margin positions, is applied to the reconstruction of the glacial ice covers of Greenland and the Canadian Arctic islands. In the northern regions, two different reconstructions have been performed with ice margins along the present 600 and 200 m sea-depth contours, respectively. In central Greenland, the ice margin is considered to be at the outermost ice-margin deposits on the coastal shelf to the west, and at the present 200 m sea-depth contour to the east.The main conclusions to be drawn from the reconstructions are: (1). The flow pattern of the glacial ice cover of Greenland shows a great resemblance to the present one, the central ice divide being displaced less than 50 km from its present position and being no more than 200 m higher than today. (2). The main ice divide of the ice sheet covering the Canadian Arctic islands (the Innuitian ice sheet) was located over the highlands of eastern Ellesmere Island with local domes positioned over the present ice caps, indicating that even the deep ice of Wisconsin age in these ice caps is of local origin. This is also the case for the Devon Island ice cap. (3). Even in the not very likely case of a rather extensive glacial ice cover in north-west Greenland, the ice-flow pattern upstream of the Camp Century deep drill site would not have changed radically compared to the present flow pattern. Thus it is concluded that even advanced ice margins in late-Wisconsin time could at most have resulted in an elevation of the deposition site of the late-Wisconsin ice at Camp Century 600 m higher than at present. The consequences of this conclusion are discussed.

Upper Ordovician to Silurian facies patterns in eastern Ellesmere Island and western North Greenland and their bearing on the Nares Strait lineament

The upper Ordovician and lower Silurian sediments in the northern Nares Strait region formed during a series of platform margin collapses and platform subsidences. Facies changes from platform carbonates to slope and trough elastics are intricate, but two almost vertical facies fronts can be correlated across Nares Strait. The northernmost facies front is the carbonate platform margin (associated with a horst) which apparently formed at the fault-bounded edge of the stable craton. At this margin there is a facies boundary (interdigitation) between platform carbonates and elastics of the trough and this feature had a stationary location during the upper Ordovician and lower Silurian. On Ellesmere Island it is traceable from Cañon Fiord to Judge Daly Promontory; on Greenland, directly along strike, available data indicate that the linear coastline of northern Hall Land, and probably Nyeboe Land, coincides with the platform margin. There appears to have been little or no post-depositional offset of this margin along Nares Strait. Mudstones progressively migrated southward in Ellesmere Island during the upper Ordovician and the same facies reached Washington Land and Hall Land, Greenland, in the middle Llandovery (lower Silurian). The line of interdigitation (facies front) between carbonate and mudstone facies was a static, near vertical, feature from the middle Llandovery to upper Silurian in Washington Land and into the lower Devonian in Ellesmere Island. This facies boundary has a slightly curved form when projected across Nares Strait; a shape which is entirely consistent with the meandering nature of facies boundaries. The present distribution and relationship of upper Ordovician to lower Silurian sediments indicate that they were part of a single laterally continuous sedimentary regime. Both vertical facies fronts arc entirely consistent with no post-depositional movement along Nares Strait; however, they cannot rule out left-lateral displacement of as much as 25 km. Displacements greater than this introduce far more geological problems than they solve.

A.H. Joy (1887-1932)

Inspector Alfred Herbert Joy of the Royal Canadian Mounted Police is best known for a remarkable 1800-mile (2900-km) patrol by dogsled across the heart of the Queen Elizabeth Islands in 1929. He had a keen interest in and extensive knowledge of the Arctic, its wildlife and people, and was dedicated to upholding the law and jurisdiction of Canada in isolated arctic regions. ... In 1921, following Canada's decision to extend jurisdiction into the Arctic Islands, Joy was selected to represent the government at Pond Inlet, northern Baffin Island. Soon after his arrival he undertook investigation of the Janes murder case. Joy travelled to Cape Crauford in December, where he found and exhumed Janes's body and conducted an autopsy. Later, in his capacity as coroner, he held an inquest and gathered a jury, the accused, and witnesses from as far away as Igloolik, in addition to presiding as Justice of the Peace at the trial. Following the trial he received a notable tribute from Mr. Justice Rivet for his outstanding work on this case-particularly for his thoroughness and fairness. He had enforced the law in the Arctic Islands for the first time. In 1924, Joy made a hair-raising attempt to cross Lancaster Sound by dogsled from northern Baffin Island to test the practicability of communicating with the R.C.M.P. detachment on Ellesmere Island. ... After 1925, when Joy took over detachments on eastern Ellesmere Island (Craig Harbour, Bache Peninsula) and Devon Island (Dundas Harbour), he began a series of long exploratory patrols across the Queen Elizabeth Islands which would do credit to any great polar explorer. During these trips he was able to correct errors on maps, explore new sled routes, make notes on wildlife, vegetation, coal outcrops, archaeological sites, sites of historic interest, weather, and sea-ice conditions. His detailed remarks on the numbers and migration of Peary caribou among the Queen Elizabeth Islands and the long distances arctic hares can travel on their hind legs are of great biological interest. He also foresaw new ways of patrolling the High Arctic, stating: It would be possible, if necessary, I believe, to carry on an extensive survey of the islands west of Eureka sound by aeroplane. He made important biological and archaeological collections for what is now the national Museums of Canada. His collection of 700 specimens from a Palaeo-Eskimo site was acknowledged by the Chief of the Division of Anthropology to be ... one of the most valuable accessions that the Division has received since I took charge of it in 1910. ... Joy's end was tragic. He died at the age of 43, apparently of a stroke, on the morning of the day he was to be married in Ottawa. ...