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Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Research on climate change impacts, vulnerability and adaptation, particularly projects aiming to contribute to practical adaptation initiatives, requires active involvement and collaboration with community members and local, regional and national organizations that use this research for policy-making. Arctic communities are already experiencing and adapting to environmental and socio-cultural changes, and researchers have a practical and ethical responsibility to engage with communities that are the focus of the research. This paper draws on the experiences of researchers working with communities across the Canadian Arctic, together with the expertise of Inuit organizations, Northern research institutes and community partners, to outline key considerations for effectively engaging Arctic communities in collaborative research. These considerations include: initiating early and ongoing communication with communities, and regional and national contacts; involving communities in research design and development; facilitating opportunities for local employment; and disseminating research findings. Examples of each consideration are drawn from climate change research conducted with communities in the Canadian Arctic. [ABSTRACT FROM AUTHOR]

This paper presents a detailed study of animal bones from a Late Dorset house structure and midden at the Bell site, Victoria Island. Previous research has shown seal to be the staple resource of Late Dorset subsistence in most other regions. Bones of terrestrial mammals such as caribou are rarely found in Late Dorset sites, leading researchers to suggest that Late Dorset people may not have been actively hunting caribou or that caribou population numbers were low during the Late Dorset period across much of the eastern Arctic. In contrast to other sites, faunal remains from the Bell site indicate that Late Dorset people living there were primarily dependent on caribou and Arctic char, and relied only minimally on seal. Thus, the Bell site presents a rare opportunity to understand terrestrial aspects of the Late Dorset economy. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Indigenous adolescents in Canada are among those shouldering the impacts of colonialism and racism. Peer approaches and art-and-land-based programming have demonstrated promise to support empowerment and well-being, yet little is known about their efficacy with Northern and Indigenous adolescents in Canada or of how this group conceptualises empowerment. Fostering Open eXpression among Youth (FOXY) and Strength, Masculinities, and Sexual Health (SMASH) conduct land-and-arts-based Peer Leader Retreats with adolescents from the Northwest Territories, Nunavut and the Yukon Territories. Retreats (2017–2019) included 286 participants (n=196 women [trans-inclusive], n=84 men [trans-inclusive], n=5 non-binary), aged 12–19, the majority of whom (n=235) were Indigenous. Participants completed surveys immediately before and following retreats and 6 months after. Focus group discussions (FGDs) (n=24) were conducted with participants (peer leaders and apprentices) (n=232) following the retreat, and youth staff members (peer facilitators) (aged 14–21, n=7 FGDs). Applying thematic analysis, we explored retreat experiences (FGDs), and Wilcoxon signed-rank tests to examine pre/post retreat changes in leadership, empowerment, and self-confidence (surveys). Quantitatively, there were statistically significant increases in leadership and empowerment in post-retreat scores compared to preretreat. Qualitatively, findings demonstrate how Peer Leader Retreats premised on land-and-art-based approaches can support empowerment, confidence, leadership, and social-connectedness. [ABSTRACT FROM AUTHOR]

Abstract: The story of oil and gas exploration in the Arctic Islands of Canada and in the Sverdrup Basin of that region is largely the story of Panarctic Oils Limited. Panarctic was incorporated May 27, 1966 by Federal Letters Patent and operations started in 1968 with the first seismic work. J.C. Sproule of Calgary was a major force behind its formation. Panarctic was an industry/government consortium established to explore for oil and gas in the Canadian Arctic Islands, with up to 37 participating companies. Panarctic drilled 150 wells over an area measuring some 850 by 1200km. The most northerly well was located approximately 80°45′ N on Ellesmere Island and the most southerly well was at 72°40′ N on Prince of Wales Island. 38 of these wells were drilled offshore from floating ice platforms in water depths of up to 550m. 500km3 (17.5trillionft3) of natural gas reserves was discovered over this period and small oil reserves were discovered at Bent Horn. All of the offshore wells attempted were drilled, logged and tested as planned, a proof of the viability of using ice as a support for drilling. In spite of large distances, extreme weather and permafrost, the operations were successful and had no lasting effect on the environment. This paper summarizes the significant achievements over Panarctic''s history from inception to 1986 when operations ceased. [Copyright &y& Elsevier]

In the eastern Canadian Arctic, a shift in toolstone selection strategies from pre-dorset (4500-2800 B.P.) to dorset (2500-1000 B.P.) has been interpreted as one line of evidence indicating culture change within the palaeo-Eskimo continuum. pre-dorset toolmakers appear to have relied on readily available local cherts while dorset toolmakers were more discriminating, frequently using scarce or non-local toolstones such as chalcedony from northern labrador, crystal quartz, and nephrite, among others. our recent analysis of a debitage assemblage from ledx-42, a multi-component palaeo-Eskimo site located in the interior of southern Bafin island, aimed to see if similar raw material signatures could be isolated using a newly developed methodological approach for sourcing chert toolstone. one of our objectives in this preliminary study was to evaluate if diversity in chert selection strategies could be used as a proxy to assess possible links between cultural affiliation and activity areas within the site. this paper describes the sourcing protocol and discusses our results as they relate to the palaeo-Eskimo exploitation of chert toolstone at LeDx-42. [ABSTRACT FROM AUTHOR]

In June 2001 the federal Government of Canada enacted new Regulations governing archaeological fieldwork in Yukon, Northwest Territories and Nunavut. In this paper we provide a brief overview of the history of archaeological site protection in the former Northwest Territories, and describe the nature of the changes that are now in effect in the new Nunavut and Northwest Territories. [ABSTRACT FROM AUTHOR]

Victoria Island in Canada's western Arctic is the eighth largest island in the world and the second largest in Canada. Here, we report the results of a floristic study of vascular plant diversity of Victoria Island. The study is based on a specimen-based dataset comprising 7031 unique collections from the island, including some 2870 new collections gathered between 2008 and 2019 by the authors and nearly 1000 specimens variously gathered by N. Polunin (in 1947), M. Oldenburg (1940s-1950s) and S. Edlund (1980s) that, until recently, were part of the unprocessed backlog of the National Herbarium of Canada and unavailable to researchers. Results are presented in an annotated checklist, including keys and distribution maps for all taxa, citation of specimens, comments on taxonomy, distribution and the history of documentation of taxa across the island, and photographs for a subset of taxa. The vascular plant flora of Victoria Island comprises 38 families, 108 genera, 272 species, and 17 additional taxa. Of the 289 taxa known on the island, 237 are recorded from the Northwest Territories portion of the island and 277 from the Nunavut part. Thirty-nine taxa are known on the island from a single collection, seven from two collections and three from three collections. Twenty-one taxa in eight families are newly recorded for the flora of Victoria Island: Artemisia tilesii, Senecio lugens, Taraxacum scopulorum (Asteraceae); Crucihimalaya bursifolia, Draba fladnizensis, D. juvenilis, D. pilosa, D. simmonsii (Brassicaceae); Carex bigelowii subsp. bigelowii, Eriophorum russeolum subsp. albidum (Cyperaceae); Anthoxanthum monticola subsp. monticola, Bromus pumpellianus, Deschampsia cespitosa subsp. cespitosa, D. sukatschewii, Festuca rubra subsp. rubra, Lolium perenne, Poa pratensis subsp. pratensis (Poaceae); Stuckenia filiformis (Potamogetonaceae); Potentilla ×prostrata (Rosaceae); Galium aparine (Rubiaceae); and Salix ovalifolia var. ovalifolia (Salicaceae). Eight of these are new to the flora of the Canadian Arctic Archipelago: Senecio lugens, Draba juvenilis, D. pilosa, Anthoxanthum monticola subsp. monticola, Bromus pumpellianus, Deschampsia cespitosa subsp. cespitosa, Poa pratensis subsp. pratensis and Salix ovalifolia var. ovalifolia. One of these, Galium aparine, is newly recorded for the flora of Nunavut. Four first records for Victoria Island are introduced plants discovered in Cambridge Bay in 2017: three grasses (Festuca rubra subsp. rubra, Lolium perenne, and Poa pratensis subsp. pratensis) and Galium aparine. One taxon, Juncus arcticus subsp. arcticus, is newly recorded from the Northwest Territories. Of the general areas on Victoria Island that have been botanically explored the most, the greatest diversity of vascular plants is recorded in Ulukhaktok (194 taxa) and the next most diverse area is Cambridge Bay (183 taxa). The floristic data presented here represent a new baseline on which continued exploration of the vascular flora of Victoria Island - particularly the numerous areas of the island that remain unexplored or poorly explored botanically - will build. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Brucella serostatus was evaluated in 3189 muskoxen sampled between 1989 and 2016 from various locations of the Canadian Arctic archipelago and mainland, near the communities of Sachs Harbour and Ulukhaktok, Northwest Territories, and Cambridge Bay and Kugluktuk, Nunavut. Brucella antibodies were found only in muskoxen sampled around Cambridge Bay, both on southern Victoria Island and on the adjacent mainland (Kent Peninsula). Consistent with participatory epidemiology data documented from local harvesters describing increased Brucella-like syndromes (swollen joints and lameness) and a decreased proportion of juveniles, the apparent Brucella seroprevalence in the sampled muskoxen of the Cambridge Bay area increased from 0.9% (95% CI 0.3–2.1) in the period of 1989–2001 to 5.6% (95% CI 3.3–8.9) in 2010–2016. The zoonotic bacteria Brucella suis biovar 4 was also cultured from tissues of muskoxen sampled on Victoria Island near Ulukhaktok in 1996 (n = 1) and Cambridge Bay in 1998, 2014, and 2016 (n = 3). Overall, our data demonstrate that B. suis biovar 4 is found in muskoxen that are harvested for food and by guided hunts on Victoria Island and Kent Peninsula, adding an important public health dimension to this study. Robust participatory epidemiology data on muskox health and diseases greatly enhanced the interpretation of our Cambridge Bay data and, combined with the serological and microbiological data, provide compelling evidence that the prevalence of B. suis biovar 4 has increased in this area since the late 1990s. This study enhances the available knowledge on Brucella exposure and infection in muskoxen and provides an example of how scientific knowledge and local knowledge can work together to better understand disease status in wildlife. [ABSTRACT FROM AUTHOR]

This article traces the historical development of post-seco ndary education in the Western and Eastern Arctic from the end of the Second World War to the late 1980s and explores the role that southern Canadian universities have played in carrying out the socio-economic goals of nation building in the North. Writing from an interdisciplinary perspective, I argue that the history of higher education in the North should be situated within the context of settler colonialism, Canadian nationalism, resource extraction, and the struggle for Indigenous self-determination. The debate around a "bricks and mortar" northern university is ongoing, and this article brings attention to the questions and concerns of the past in order to inform present and future dialogue around post-secondary education in the North. [ABSTRACT FROM AUTHOR]

Regional geological mapping of the glaciated surface of northwestern Victoria Island in the western Canadian Arctic revealed an anomalous structure in otherwise flat-lying Neoproterozoic and lower Paleozoic carbonate rocks, located south of Richard Collinson Inlet. The feature is roughly circular in plan view, approximately 25 km in diameter, and characterized by quaquaversal dips of approximately 45°, decreasing laterally. The core of the feature also exhibits local vertical dips, low-angle reverse faults, and drag folds. Although brecciation was not observed, shatter cones are pervasive in all lithologies in the central area, including 723 Ma old dikes that penetrate Neoproterozoic limestones. Their abundance decreases distally, and none was observed in surrounding, horizontally bedded strata. This circular structure is interpreted as a deeply eroded meteorite impact crater of the complex type, and the dipping strata as the remnants of the central uplift. The variation in orientation and shape of shatter cones point to variably oriented stresses with the passage of the shock wave, possibly related to the presence of pore water in the target strata as well as rock type and lithological heterogeneities, especially bed thickness. Timing of impact is poorly constrained. The youngest rocks affected are Late Ordovician (approximately 450 Ma) and the impact structure is mantled by undisturbed postglacial sediments. Regional, hydrothermal dolomitization of the Ordovician limestones, possibly in the Late Devonian (approximately 360 Ma), took place before the impact, and widespread WSW- ENE-trending normal faults of probable Early Cretaceous age (approximately 130 Ma) apparently cross-cut the impact structure. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The spatial (i.e. microhabitat) and temporal (i.e. seasonal) characteristics of diatom assemblages in adjacent High Arctic lakes were studied intensively June-August 2004. These baseline data are used to improve understanding of modern diatom community dynamics, as well to inform paleoenvironmental reconstructions. Diatoms were collected approximately weekly through the melt season from each principal benthic substrate (moss/macrophyte, rock scrapes, littoral sediment), plankton, and sediment traps, and were compared to the uppermost 0.5 cm of a surface core obtained from the deepest part of the lake where sediment cores are routinely collected. Water samples were collected concurrently with diatom samples to investigate species-environment relationships. The lakes share approximately half of their common taxa, the most abundant overall in both lakes being small Cyclotella species. Results of detrended correspondence analysis (DCA) indicate that the largest gradient in species turnover existed between benthic and planktonic communities in both lakes, and that sediment trap and the surface core top samples most closely resemble the planktonic assemblage, with an additional contribution from the lotic environment. Our results indicate clear micro-spatial controls on species assemblages and a degree of disconnection between the benthos and deep lake sediments that manifests as an under-representation of benthic taxa in deep lake surface sediments. These findings are particularly relevant in the context of interpreting the paleoenvironmental record and assessing ecosystem sensitivity to continued climate change. [ABSTRACT FROM AUTHOR]

Information about wolf (Canis lupus) movements anywhere near the northern extreme of the species' range in the High Arctic (>75uN latitude) are lacking. There, wolves prey primarily on muskoxen (Ovibos moschatus) and must survive 4 months of 24 hr/day winter darkness and temperatures reaching 253 C. The extent to which wolves remain active and prey on muskoxen during the dark period are unknown, for the closest area where information is available about winter wolf movements is >2,250 km south. We studied a pack of ⩾20 wolves on Ellesmere Island, Nunavut, Canada (80uN latitude) from July 2009 through mid-April 2010 by collaring a lead wolf with a Global Positioning System (GPS)/Argos radio collar. The collar recorded the wolf's precise locations at 6:00 a.m. and 6:00 p.m. daily and transmitted the locations by satellite to our email. Straight-line distances between consecutive 12-hr locations varied between 0 and 76 km. Mean (SE) linear distance between consecutive locations (n = 554) was 11 (0.5) km. Total minimum distance traveled was 5,979 km, and total area covered was 6,640 km2, the largest wolf range reported. The wolf and presumably his pack once made a 263-km (straight-line distance) foray to the southeast during 19-28 January 2010, returning 29 January to 1 February at an average of 41 km/day straight-line distances between 12-hr locations. This study produced the first detailed movement information about any large mammal in the High Arctic, and the average movements during the dark period did not differ from those afterwards. Wolf movements during the dark period in the highest latitudes match those of the other seasons and generally those of wolves in lower latitudes, and, at least with the gross movements measurable by our methods, the 4-month period without direct sunlight produced little change in movements. [ABSTRACT FROM AUTHOR]

The article focuses on the climactic, economic, and political realities of oil and gas exploration and development in the Canadian Arctic. The author suggests that potential oil or gas discoveries does not mean the economics or the environmental costs justify the efforts in getting the product to the markets. It mentions that the country has enforced a moratorium on off shore drilling due to the risks it brings like the massive 2010 Macondo deep water oil spill in the Gulf of Mexico. It mentions several changes that Canada has to do before exploiting its oil and gas in the North including the ability to control the Northwest Passage, and requiring of a requisite shipping facilities and monitoring systems.

A review of the ages determined for mantle material (xenoliths and xenocrysts entrained in kimberlite) derived from the Slave Province continental lithospheric mantle (CLM) indicates that a portion of the central Slave lithosphere may be ancient (3.5–3.3 Ga) harzburgite, but the majority of this lithosphere is much younger (2.9–2.0 Ga). Relying on the most robust chronometers, the majority of Slave lithosphere peridotite formed in the Neoarchean (peak at 2.75 Ga), whereas the majority of eclogite formed in the Paleoproterozoic (2.2–2.0 Ga). The northern Slave lithosphere contains evidence of peridotite xenolith ages that young with depth. The Paleoproterozoic eclogites may have multiple origins including remnants of subducted oceanic crust and mafic–ultramafic magmas that crystallized at great depth (100–200 km). Re–Os studies of sulfide inclusions in diamond indicate that some diamonds currently mined are ancient (~3.5 Ga), but many Slave diamonds could be considerably younger. Most eclogitic diamonds recovered from the Slave craton are interpreted to be related to the formation of Paleoproterozoic eclogite. There is abundant evidence for Mesoproterozoic modification of the Slave lithosphere (e.g., heating by magma emplacement at great depth and metasomatism) and possible new addition to the lithosphere at that time. The Canadian Slave and African Kaapvaal lithospheres have similar peaks in cratonic peridotite formation ages at about 2.8 Ga, indicating that a large portion of the CLM in these two cratons formed and stabilized in the Neoarchean. One difference is that the Slave peridotites are much less enriched in SiO2, possibly reflecting the more metasomatized nature of the Kaapvaal CLM. The dominance of Paleoproterozoic formation ages for Slave mantle eclogites contrasts with the dominance of Neoarchean formation ages for Kaapvaal mantle eclogites. Une révision des âges déterminés sur des matériaux du manteau provenant du manteau lithosphérique continental de la Province des Esclaves (des xénolites et des xénocristaux entraînés dans de la kimberlite) indique qu’une portion de la lithosphère centrale des Esclaves pourrait être une ancienne harzburgite (3,5–3,3 Ga) mais que la plus grande partie de cette lithosphère est beaucoup plus jeune (2,9–2,0 Ga). En se basant sur les chronomètres les plus robustes, la plus grande partie de la peridotite de la lithosphère des Esclaves s’est formée au Néoarchéen (crête à 2,75 Ga) alors que la plus grande partie de l’éclogite s’est formée au Paléoprotérozoïque (2,2–2,0 Ga). La lithosphère nord des Esclaves contient des évidences d’âges de péridotite xénolite qui rajeunissent en profondeur. Les éclogites datant du Paléoprotérozoïque peuvent avoir de multiples origines, incluant des lambeaux de croûte subductée et des magmas mafiques–ultramafiques qui se sont cristallisés à de grandes profondeurs (100–200 km). Des études Re–Os des inclusions de sulfures dans les diamants indiquent que quelques diamants actuellement exploités sont anciens (~3,5 Ga) mais que plusieurs des diamants provenant de la Province des Esclaves pourraient être beaucoup plus jeunes. La plupart des diamants de paragenèse éclogitique provenant du craton des Esclaves sont interprétés comme étant reliés à la formation de l’éclogite paléoprotérozoïque. Il existe beaucoup de preuves de modifications, au Mésoprotérozoïque, de la lithosphère des Esclaves (p. ex. un réchauffement par la mise en place de magma à grande profondeur et du métasomatisme) et l’ajout possible de nouvelle lithosphère à ce moment. Les lithosphères des Esclaves et de Kaapvaal ont des crêtes similaires dans la formation de la péridotite cratonique vers environ 2,8 Ga, indiquant qu’une grande portion du manteau lithosphérique cratonique dans ces deux cratons s’est formée et s’est stabilizée à ce moment. Une différence est que les péridotites des Esclaves sont beaucoup moins enrichies en SiO2, reflétant possiblement la nature plus métasomatisée du manteau lithosphérique cratonique Kaapvaal. La dominance des âges de formation paléoprotérozoïques pour les éclogites du manteau des Esclaves contraste avec la dominance des âges de formation néoarchéens pour les éclogites du manteau du Kaapvaal. [ABSTRACT FROM AUTHOR]

Objectives. Societies that foster socially supportive networks produce healthier populations. Social support is a significant determinant of health among Canada's Inuit population; however, little is known about the characteristics that provide access to social support among Inuit. This exploratory analysis describes how 4 types of social support (namely, positive social interaction, emotional support, tangible support and affection and intimacy) differ in relation to various determinants of health. Study design. Micro-data from the Arctic Supplement of the 2001 Aboriginal Peoples Survey (n=26,290) was used. Methods. Cross-tabulations and multivariate logistic regression analyses were used to examine levels (high/low) of the 4 types of social support among the full Inuit sample (n=26,290) as they relate to age, gender, geographic region, marital status, Aboriginal language use and participation in traditional harvesting activities. Results. Certain subsegments of the Inuit population were less likely to report high levels of social support, including men, the elderly (aged 55+) and the unmarried. Some Inuit-relevant determinants were also found to decrease the odds of reporting high levels of social support, including being unable to speak or understand an Aboriginal language, not participating in traditional harvesting activities and living in Nunavik. Conclusions. Research that frames Inuit health within the social determinants of health is in its relative infancy; however, evidence from the social epidemiological literature indicates that those with diminished access to social support also suffer poorer health outcomes. Future research should build on the findings of this study to examine how the relationship between various health outcomes (e.g., respiratory disease, suicide attempts, self-rated health) and social support may respond along a social gradient. Such analysis will build on the paucity of literature specific to Inuit health and social conditions and set priorities for policy and programming efforts that will improve the social determinants of Inuit health. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Studies the physical, chemical and biological characteristics of Meretta Lake in Cornwallis Island, Nunavut, between 1992 and 1999 to determine its rate of eutrophication. Media through which the lake has been receiving sewage since 1949; Decline in nutrient concentrations of the lake; Decrease in eutrophication of the lake during 1990s.

An Archaean carbonatite-bearing alkaline complex, the Grays Bay alkaline complex, has been mapped in the Slave Province of northwestern Canada. It consists of five sequentially emplaced phases: a melanocratic syenite, a carbonatite and silico-carbonatite, a pegmatitic biotite syenite and fine-grained biotite–clinopyroxene–plagioclase gabbro dykes The entire complex is tightly folded in concert with late Archaean regional upright folding. A minimum age of 2605.8+2.8/–2.5 Ma for the melanocratic syenite is determined by U/Pb dating of titanite, an alteration product o primary ilmenite. A single concordant zircon from the same unit, interpreted as xenocrystic, places an upper age limit of ∼2.67 Ga. Monazite from the carbonatite yields an age of 2594.8 ±2.0 Ma, indicating that a minimum of 6.5 my passed between the intrusion of syenite and carbonatite magmas. A second carbonatite-bearing complex in the southwestern Slave Province, the Leith Lake carbonatite, was dated by U/Pb titanite at 2591.8+3.3/–2.8 Ga, within error of the Grays Bay alkaline complex. The synchroneity between the two widely separated complexes suggests that intrusion of these bodies may have been a pan-Slave Province event. The carbonatite complexes are temporally coincident with two major tectonic events in the Slave Province: (1) emplacement of voluminous, crustally derived monzogranite to granodiorite plutons between ∼2.61 and 2.59 Ga; (2) deposition of polymictic conglomerate after ∼2.60 Ga within localized fault-bounded basins. Both events are represented in the Grays Bay area. The duration of uplift and conglomerate deposition is poorly defined, but coincident deformation of conglomerates, the alkaline complexes and granitic plutons suggests a terminal compressive event after 2.59 Ga. [ABSTRACT FROM AUTHOR]

A peat deposit on Ellesmere Island, Nunavut, Canada, allows a unique glimpse of the Early Pliocene terrestrial biota north of the Arctic Circle. The peat accumulated in a beaver pond surrounded by boreal larch forest near regional tree line in coastal hills close to the Arctic Ocean. The ecological affinities of the plant and beetle remains contained in the peat indicate that winter temperatures on Ellesmere Island were nearly 15?°C higher and summer temperatures 10?°C higher than they are today. Here we show that the mammalian remains buried in the peat represent mainly taxa of Eurasiatic zoogeographic and phyletic affinities, including the first North American occurrence of a meline badger (Arctomeles). This deposit contains direct evidence of the composition of an Early Pliocene (4-5 million years ago) arctic mammalian fauna during an active period of interchange between Asia and North America. [ABSTRACT FROM AUTHOR]