Wager Bay Research Articles

Long-lived deformation history recorded along the Precambrian Thelon and Judge Sissons faults, northeastern Thelon Basin, Nunavut

The east–northeast-striking Thelon and Judge Sissons faults of south-central Nunavut are well preserved and record long-lived dextral transcurrent movement with complex reactivation and fluid flow histories. The faults cut across Archean gneisses, Paleoproterozoic plutons, and a Mesoproterozoic sedimentary basin in the Rae domain of the western Churchill Province. They formed and were reactivated during multiple deformation events beginning with an initial faulting event at 1830–1760 Ma, followed by an epithermal faulting event at 1760–1750 Ma and late reactivation events at 1600–1300 Ma. The initial faulting event produced the core-damage zone architecture of the faults. Damage zones are characterized by multiple fracture sets, quartz veins and hydrothermal crackle breccias, surrounding core zones defined by multiple mosaic to chaotic breccias and cataclasites with dextral slip indicators. The epithermal faulting event is expressed by the presence of crosscutting comb, crustiform-cockade and lattice-bladed quartz ± hematite ± carbonate veins, and is likely associated with a magmatic event of similar age. The late reactivation events resulted in the formation of irregular, non-cohesive crackle to mosaic breccias and gouges, which became the primary pathways for uranium-bearing hydrothermal fluids and the formation of unconformity-type uranium deposits. The Thelon and Judge Sissons faults are similar to other major continental faults in the Rae domain (e.g., McDonald fault, Wager Bay shear zone), which formed during the Paleoproterozoic Taltson–Thelon and Trans-Hudson orogenies and to modern analogues, such as the Karakorum, Altyn Tagh, and Hunan–Jiangxi faults, which formed during the Himalayan–Tibetan orogeny and experienced prolonged hydrothermal and even hot spring activity.

A new map of glacigenic features and glacial landsystems in central mainland Nunavut, Canada

A new digital map of glacial geomorphic features and interpreted glacial landsystems was produced for an area covering ~415 000 km2 in the Keewatin Sector of the Laurentide Ice Sheet (LIS) in Nunavut. The map integrates information from previous surficial geology maps and >14 000 field stations, and is significantly improved by the detailed inventory of ~152 000 glacigenic features using high‐resolution ArcticDEM data and Landsat 8 imagery. From this, we identify and map coherent patterns of landform development (landsystems) between the Manitoba border and the Arctic coast, many of which are entirely new and others that are significantly modified or updated. In particular, we recognize six separate ice streams, including one probable remnant ice stream, and we delineate numerous palimpsest streamlined landscapes with associated ice‐flow trends and relative ages. A continuum of relict terrains with varying basal ice thermal conditions is mapped for the first time in the ice divide migration zone between Baker Lake and Wager Bay. In addition, deglacial cold‐based retreat terrains and preserved warm‐based landscapes unaffected by younger glacial events have been identified. These new georeferenced, multi‐scale data sets and interpreted glacial landsystems provide a comprehensive framework to strengthen reconstructions of the glacial history and dynamics of one of the largest ice domes of the LIS, identify distinct glacial sediment transport paths for applications to mineral exploration, and test numerical modelling of the LIS in support of climate change studies and long‐term evolution of modern ice sheets.

Mapping Surficial Materials in South of Wager Bay Area (Nunavut) Using RADARSAT-2 C-HH and C-HV, Landsat-8 OLI, DEM and Slope Data

For anarea south of Wager Bay, Nunavut (NTS map sheets 046D, E, 055P, 056A, H), a map detailing 22 surface material classes was produced using a non-parametric classifier, Random Forests, applied to a combination of RADARSAT-2 C-band dual- polarized (horizontal transmitted and horizontal received (HH) and horizontal transmitted and vertical received (HV)) and Landsat-8 OLI images with a digital elevation model and slope data. We show that the addition of RADARSAT-2 C-HH and C-HV images to the optical Landsat-8 OLI image in the classification process increases the overall classification accuracy from 96.7% to 99.3%. Similarly, the accuracy determined by comparing the resulting maps with georeferenced field data (i.e., mapping accuracy) increases from 72.1% to 78.0% when RADARSAT-2 C-HH and C-HV imagesare added to the classification. The material classes with the highest mapping accuracies were flooded alluvium and boulders, both with 100%. The class with the lowest mapping accuracy was thin sand and gravel over bedrock (11.1%), commonly confused with sand and gravel with vegetation and bedrock. Adding RADARSAT-2 data in the classification increases also the mapping accuracy that was established by comparing to georeferenced point observations.

A method for curvilinear structure mapping in normalized derivative magnetic maps

Enhancement techniques are frequently applied on magnetic field maps to facilitate the interpretation of geological units and structures. Among them, the normalized derivative (ND) approach represents a class of techniques specifically designed to balance weak and strong anomalies (Fairhead and Williams, 2006). In this paper, we present an approach for the enhancement, detection and mapping of curvilinear structures in ND magnetic maps. The proposed approach locates ridges and valleys in ND maps using multiscale Hessian analysis and filtering, non-maxima suppression and morphological thinning with anchor points. The efficiency of the method is demonstrated on four different magnetic map subsets with differing geological settings. A practical application of the method is demonstrated using the magnetic maps from the Tehery Lake – Wager Bay region of Nunavut, Canada. Geological features are effectively defined, highlighting near surface structures and key units that are important for understanding the mineral potential of the region.

Subpopulation structure of caribou (Rangifer tarandusL.) in arctic and subarctic Canada

Effective management and conservation of species, subspecies, or ecotypes require an understanding of how populations are structured in space. We used satellite-tracking locations and hierarchical and fuzzy clustering to quantify subpopulations within the behaviorally different barren-ground caribou (Rangifer tarandus groenlandicus), Dolphin and Union island caribou (R. t. groenlandicus x pearyi), and boreal (R. t. caribou) caribou ecotypes in the Northwest Territories and Nunavut, Canada. Using a novel approach, we verified that the previously recognized Cape Bathurst, Bluenose-West, Bluenose-East, Bathurst, Beverly, Qamanirjuaq, and Lorillard barren-ground subpopulations were robust and that the Queen Maude Gulf and Wager Bay barren-ground subpopulations were organized as individuals. Dolphin and Union island and boreal caribou formed one and two distinct subpopulation, respectively, and were organized as individuals. Robust subpopulations were structured by strong annual spatial affiliation among females; subpopulations organized as individuals were structured by migratory connectivity, barriers to movement, and/or habitat discontinuity. One barren-ground subpopulation used two calving grounds, and one calving ground was used by two barren-ground subpopulations, indicating that these caribou cannot be reliably assigned to subpopulations solely by calving-ground use. They should be classified by annual spatial affiliation among females. Annual-range size and path lengths varied significantly among ecotypes, including mountain woodland caribou (R. t. caribou), and reflected behavioral differences. An east-west cline in annual-range sizes and path lengths among migratory barren-ground subpopulations likely reflected differences in subpopulation size and habitat conditions and further supported the subpopulation structure identified.

Historical Population Characteristics of Bowhead Whales (<i>Balaena mysticetus</i>) in Hudson Bay

Historical records of commercial whalers operating in northwestern Hudson Bay during the 19th century were examined for information on size, age, sex, and location of bowhead whales that were either sighted or killed. Correlations between body size and either oil yield or baleen length were used to estimate the relative age classes (calf, subadult, adult) of whales for which no explicit age-class information was reported in the whaling logbooks. Cow-calf pairs and subadults, as well as adult whales, were sighted or killed throughout the whaling season in the area extending from Wager Bay south to Marble Island. This finding indicates that whales of many different age classes were present south of Wager Bay, even during the open-water period when whaling activity shifted northward to include Repulse Bay and Lyon Inlet. Recent observations suggest that few bowhead whales occur south of Wager Bay during the open-water season and that the population in this area has not recovered from the effects of commercial whaling. It is not clear whether this group of bowheads was a separate stock or, alternatively, waters south from Wager Bay constituted a second calf-rearing area for a single Hudson Bay-Foxe Basin stock.

Bryophytes of the Wager Bay Region, District of Keewatin, Northwest Territories

Bryophytes of the Wager Bay Region, District of Keewatin, Northwest Territories

Generation and interpretation of geophysical images with examples from the Rae Province, northwestern Canada shield

Different types of images generated from gravity, magnetic, and gamma ray spectrometry data from the Rae Province of the Canadian shield were compared with each other and geologic maps to evaluate their effectiveness for displaying the geologically relevant content of the data sets. Shading methods were useful for enhancing weak directional anomalies in the aeromagnetic data. Multi‐directional, shaded‐relief images produced by overlaying three colored, shaded‐relief images are useful for analysis of anomalies associated with structure. Vertical gravity derivative images display a continuous gravity feature linking the Wager Bay and Amer Lake shear zones that is obscured on the Bouguer gravity intensity image. Detailed vertical magnetic derivative images of the shear zone clearly displayed anomalies associated with the internal structure. Composite images generated using three different geophysical parameters show correlations between the magnetic, gravity, and radiometric data which can be related to the geology. Subtle variations in uranium, thorium, and potassium concentrations determined by gamma ray spectrometry can be effectively displayed using ternary radioelement images

Geometry and kinematics of Wager shear zone interpreted from structural fabrics and magnetic data

The Wager shear zone (WSZ) is characterized by progressive bending of northeast–southwest-trending aeromagnetic anomalies to the right as they merge with east–west-trending anomalies characterizing the shear zone. This feature indicates dextral net shear. Mapping of abundant and diverse asymmetrical structural fabric elements within the shear zone where it is well exposed along the south coast of Wager Bay, northwestern Hudson Bay, consistently confirmed dextral shear sense.Pervasive, dextral shear-zone mylonites were deformed by folds with hinges parallel to the shear direction (a folds), as well as by discrete, conjugate sinistral and dextral mylonitic shears. To form a folds in mylonites it is necessary for the mylonitic fabric to rotate out of a stable orientation in the plane of shear and flattening and also to rotate about an axis parallel to the shear direction, for which we have no general explanation.We conclude with the speculation that the WSZ is a strike-slip fault related to terminal collision of the Archean plate of Ungava with the Archean plate to the north marked by the 1.8 Ga Sugluk suture.

Vascular plant flora of the Wager Bay Region, District of Keewatin, Northwest Territories

Vascular plant flora of the Wager Bay Region, District of Keewatin, Northwest Territories

Christopher Middleton (ca. 1690-1770)

... He appears to have gone to sea at quite an early age, his service aboard Hudson's Bay Company ships beginning around 1719, possibly even earlier. Early in his career Middleton established his reputation as a meticulous and innovative navigator: in the spring of 1726 he published a paper in the Royal Society's Philosophical Transactions on the variation of the magnetic needle in Hudson Bay. The following year he was elected a Fellow of the Royal Society, a great honour for a ship's captain of only two years' standing. Shortly afterwards, Middleton's path crossed that of Arthur Dobbs, an influential Anglo-Irish landowner and a hard-line free trader who bitterly resented the Hudson's Bay Company's monopoly. Furthermore, Dobbs was convinced that a practicable Northwest Passage could be found via Hudson Bay and he decided to pursue its discovery, incidentally hoping to break the Company's monopoly in the process. Using his considerable influence in London, Dobbs persuaded the Admiralty to mount an expedition to search for the Northwest Passage via Hudson Bay. Further, by arranging a commission for Middleton in the Navy, Dobbs induced him to leave the company and to command this enterprise. ... Leaving Churchill on 30 June 1742, Middleton's ships headed north. They discovered and entered Wager Bay but were then locked in the bay for several weeks by drifting ice. By means of boat journeys, however, Middleton established to his own satisfaction that the Northwest Passage did not lie through Wager Bay. Emerging again into Roes Welcome Sound pushed north once more, only to have his hopes dashed on reaching the cul-de-sac of Repulse Bay. Frozen Strait was still ice-covered; hence, there was no chance of pursuing the search into Foxe Basin. Having called at Marble Island for water, Middleton sailed for home, satisfied in his own mind that there was no route to the Pacific through Hudson Bay. ... To Middleton we owe the exploration and mapping of Wager Bay, the northern part of Roes Welcome Sound, and Repulse Bay. Such a highly qualified judge as Captain W.E. Parry, for whom Middleton's discoveries were the starting point of his own second expedition, was extremely impressed by the carefulness and accuracy of Middleton's observations and surveying. It is extremely ironic that, while the names of Lieutenant John Rankin and Arthur Dobbs are commemorated in the place names of Rankin Inlet and Cape Dobbs, Christopher Middleton's name appears nowhere on the map of the Hudson Bay area. Rectification of this situation is long overdue.

Activities of the Geographical Branch in Northern Canada, 1947-1957

The Geographical Branch of the Department of Mines and Technical Surveys was created in 1947. Under its terms of references, part of its responsibility is the collection and analysis of geographical information on northern Canada, in particular the territories under the jurisdiction of the federal government. In the decade since the Branch's inauguration, geographers have carried out various kinds of field surveys in the Canadian Arctic and subarctic, from the northern coast of Ellesmere Island to the Hudson Bay coastal plain in Ontario, and from the Alaska boundary to Labrador. These surveys have varied from parties formed entirely of geographers to individual shipboard observers or representatives on collaborative teams of scientists. The collection of basic information on the vast unknown expanses of the Arctic is peculiarly suited to the application of geographic methods. Utilizing the trimetrogon and vertical photography carried out since World War II, geographers have applied sampling techniques in interpreting larger areas, making intensive field studies of representative terrain types and expanding them by use of the air photos in delimiting, describing and analysing physiographic regions. Studies in physical geography have been the backbone of the work of the Branch in the Arctic. Air photo interpretation keys have been prepared for 14 areas: Alert, Eureka, Mould Bay, Resolute, Mackenzie Delta, Darnley Bay, Coppermine, Bathurst Inlet, Boothia Isthmus, Wager Bay, Southampton Island, Kaniapiskau-Koksoak Rivers in Ungava, the Hudson Bay Railway, and the Kenogami River. Reports on the human geography of various areas were included in the field reports and are mainly unpublished; several studies in historical geography also resulted from the field surveys. ...

Mammal Observations at Lower Back River, Northwest Territories, Canada

The Back River drains the interior barrens of the Northwest Territories of Canada. According to Blanchet (1930) the river has its headwaters in a high plateau and flows through a sand plain basin (not in accord with conditions of our base camp). The country north of the Back River drainage is of low relief. The river takes a northerly direction for the last one-third of its course. To the east, between the river and Wager Bay, the country is known to be very rugged. The first known exploration of the Back River, then called the Great Fish River, was by Sir George Back and his party, who left England in 1833 to search for Sir John Ross. Back's party wintered at Ft. Reliance. During the summer of 1834 they went down the Back River to its mouth and returned to Ft. Reliance where they again spent the winter, returning to England in 1835. In the appendix of Back's report (1836) there is a list of specimens collected and observed. The collecting was done by Mr. Richard King, surgeon to the expedition. In 1855 Chief Factor James Anderson of the Hudson's Bay Company made a similar journey (Clarke, 1940a) hoping to find traces of the ill-fated Franklin Expedition. Both these exploring trips support Stefansson's statement (1929) that much arctic exploration has been a by-product of search parties. So far as is known, Back and Anderson and their parties were the only white men who had visited in summer the area selected for the University of Minnesota-Wilkie Foundation expedition to the Back River. Members of the expedition were Dr. W. J. Breckenridge, Harvey L. Gunderson, John A. Jarosz, R. Spence Taylor, Robert J. Wilkie, James W. Wilkie and Dr. Lawrence Larson. The party was in the vicinity of Mount Meadowbank along the …