AndreaBozzo/ceres-open-data-index huggingface dataset:
Regional stream sediment geochemical data, Dawson, Yukon (NTS 116B & C)

NGR surveys were originally conducted in the Dawson map area in 1976 and 1977. Stream sediment and water samples were collected from a total of 1738 sample sites. A total of 1129 original samples were selected for reanalysis. Representative 2 gram splits were successfully recovered from 1091 samples. Samples were analysed by an ultra-trace aqua-regia digestion ICP-MS package for 53 elements.

Organization: Government of Yukon | Gouvernement du Yukon
Age of the gold-bearing White Channel Gravel, Klondike district, Yukon

Four new glass-fission-track age determinations on three distal tephra beds, together with published magnetostratigraphic and 40Ar/39Ar age data, securely place a Late Pliocene age (2.6-3.3 Ma) on the upper White Channel Gravel in the Klondike district of the Yukon. No tephra beds have been found in the lower White Channel Gravel, so its age is only loosely constrained by paleomagnetism and paleobotany, which suggest a post-Miocene and pre-Late Pliocene age.

Organization: Government of Yukon | Gouvernement du Yukon
Geology of the Whitehorse Coal Deposit

Anthracite in floodplain deposits of the Cretaceous Tantalus Formation is preserved in a west-trending graben on the south side of Mt. Granger, 24 km southwest of Whitehorse. The graben extends from Fish Lake to Double Mountain, a distance of 20 km. Two main seams are exposed by bulldozer trenches across the central part of the Mt. Granger property. The upper seam is about 1.8 m thick at surface and has been traced almost continuously over a strike length of 2 km. The lower seam is at least 3.3 m thick at surface and can be traced for more than 1 km. The seams dip at about 30 to 50 degrees to the north. Rotary drilling in 1985 on the central showing penetrated up to 22.25 m of coal. The best continuous coal intersection was 13.1 m in WC-85-6. Open pittable reserves were calculated at 180,033 tonnes over a 335 m strike length. Six days of mapping in 1987 confirmed the continuity of the two main coal seams which are deformed by open north-plunging folds. A north-trending fault along Fisher Creek cuts off massive conglomerate channel deposits interbedded with the coal in the main showing area against recessive floodplain deposits to the west where up to five coal-bearing horizons occur in a thick shale sequence. Additional reserves may lie beneath the low-lying overburden-covered area west of the Fisher Creek fault.

Organization: Government of Yukon | Gouvernement du Yukon
Provenance and depositional framework of braided and meandering gravel-bed river deposits and associated coal deposits in active intermontane piggyback basins: The Upper Jurassic to Lower Cretaceous Tantalus Formation, Yukon

The Tantalus Formation developed within confined intermontane river valleys during the late stages of collision and amalgamation of Stikinia and associated arc systems with the North American plate in Upper Jurassic and early Lower Cretaceous times. While most of the extensive chert pebble conglomerate in the Tantalus Formation can be interpreted as shallow braided gravel-bed river deposits, some may represent the products of deposition from deeper, braided and meandering gravel-bed rivers. Floodplain and lake deposits are restricted to poorly exposed slope forming intervals. Coal deposits developed locally on abandoned segments of floodplains in confined river valleys, in places associated with high constructive river deposits. The age profiles of detrital zircons indicate major contributions from reworking of older strata, combined with continued un-roofing of the Stikine terrane. In addition more distal sources were tapped in the Yukon-Tanana and adjacent terranes to the north and west of the Whitehorse trough. Much of the chert in the Tantalus Formation appears petrographically similar to chert in the Cache Creek terrane, now preserved only to the south of the Whitehorse trough. As both decrease in maximum grain size, and paleocurrents, are generally south to southwesterly trending, this source is considered unlikely. Chert may have been derived from now eroded supracrustal rocks that once formed the top of the Yukon-Tanana terrane, or more likely from an obducted block of Cache Creek terrane once present to the north and west of the Whitehorse trough. The latter may have been thrust over metamorphosed rocks of the Yukon-Tanana terrane beginning in the early Bajocian, and has subsequently been removed by erosion. A proximal North American cratonic source is excluded, as there are no Archean zircon grains in the Tantalus Formation. The possibility that strata of the Tantalus Formation may host significant conventional reserves of oil or gas is very low, due to lack of trapping mechanisms. There may be some undiscovered coal reserves, and limited potential for coal-bed methane production.

Organization: Government of Yukon | Gouvernement du Yukon
Raca property (Fawley), south Yukon

Vivid gossans associated with the Raca occurrence on the south flank of Chieftain Hill have attracted the attention of prospectors and geologists for nearly a hundred years. This copper occurrence has been categorized as a porphyry, a vein, a breccia, and as native copper associated with basic lava. Recent exploration has focused on its precious metal potential.

Organization: Government of Yukon | Gouvernement du Yukon
Surficial geology and sedimentology of Garner Creek, Ogilvie and Matson Creek map areas (115 O/13, 115 O/12, 115 N/9 - east half)

The central Yukon Territory has a number of favourable placer deposit settings due to its unique history of multiple glaciations, active stream sedimentation in association with proglacial outwash settings and terrain which has remained unglaciated.

Placer gold was found along the Stewart River on point bars in 1884 prior to the discovery of gold in the Klondike area. This was the first indication that the Yukon Territory contained important economic concentrations of placer gold.

This study is concerned with the late Tertiary and Quaternary geology in the Lower Stewart River and adjacent Yukon River above Dawson. Previous systematic surficial geological mapping and testing for placer gold on the high-level terraces along these rivers has been limited. This report describes the sedimentology and stratigraphy of key gravelly exposures in this area because similar high-level terraces in the Fortymile River drainage in Alaska had been mined for gold for many years. Work of this type also provides information on the physical characteristics of gravelly deposits (e.g., grain size distribution) which may assist regulatory decisions on placer mining in the lower Stewart and Yukon drainages.

Accompanying this report are two 1:50 000-scale surficial geology maps including marginal notes (Garner Creek, NTS 115O/13 and Matson Creek and Ogilvie NTS 115N/9 (east half) and 115O/12), as well as one 1:250 000-scale topographic map (Stewart River - NTS 115N/O) including field study site locations, heavy mineral sample sites and hardrock mineral occurrences.

Organization: Government of Yukon | Gouvernement du Yukon
Geochemistry of Devono–Mississippian volcanic and intrusive rocks of the Finlayson Lake district, Yukon-Tanana terrane, Yukon

The Finlayson Lake district in southeastern Yukon is a remnant of a Late Paleozoic arc–back-arc system that consists of metamorphosed volcanic, plutonic, and sedimentary rocks of the Yukon-Tanana and Slide Mountain terranes. These rocks host more than 40 Mt of polymetallic resources in numerous occurrences and styles of volcanogenic massive sulphide (VMS) mineralization. Geochemical data from these rocks support previous interpretations that volcanism and plutonism occurred in arc–marginal arc (e.g., Fire Lake formation) and continental back-arc basin environments (e.g., Kudz Ze Kayah formation, Wind Lake formation, and Wolverine Lake group) where felsic magmatism formed from varying mixtures of crust and mantle-derived material. The rocks have elevated high field strength element (HFSE) and rare earth element (REE) concentrations in VMS-proximal stratigraphy relative to VMS-barren assemblages, suggesting that the petrogenetic conditions that generated felsic rocks likely played a role in the localization of VMS mineralization. Future work aims to constrain magmatic processes and outline prospectivity criteria for delineating productive VMS assemblages within the district, and in similar geodynamic settings globally.

Organization: Government of Yukon | Gouvernement du Yukon
New U-Pb zircon dates from the Aishihik batholith, southern Yukon

New U-Pb zircon dates (SHRIMP and LA-ICPMS) from granitoid rocks of the Aishihik batholith indicate a range of ca. 190-180 Ma for the Long Lake plutonic suite, as previously indicated by less precise, multi-grain TIMS dates. None of the phases in the Aishihik batholith are as old as the Minto suite to the north, therefore limiting the potential for Minto-style Cu-Au-Ag mineralization in the batholith. However, local occurrences of apparently shallow-level intrusions suggest that parts of the Aishihik batholith may present suitable targets for more typical porphyry Cu-Au mineralization. LA-ICPMS U-Pb zircon dating of two orthogneiss samples from the western margin of the Aishihik batholith yielded Early Mississippian protolith ages akin to the Simpson Range plutonic suite (Yukon-Tanana terrane), and Jurassic overgrowths consistent with partial melting related to intrusion of the Aishihik batholith.

Organization: Government of Yukon | Gouvernement du Yukon
Uranium: Facts, Myths and Phobia

In the search for an alternative source of energy that would produce less green-house gas, exploration for uranium has drastically increased throughout the country. However, in the Yukon Territory, concerns about exploring for this commodity have often been voiced through the environmental assessment processes and other vehicles. It appears that the relatively low risk associated with uranium in its natural mineral forms is poorly understood. To assist with educating community members and other stakeholders about uranium, the Yukon Mining and Petroleum Environment Group has engaged the CANMET Mining and Mineral Sciences Laboratories (CANMET-MMSL) to prepare fact sheets explaining the properties of uranium and providing information on modern uranium mining, processing and end product storage. It is hoped that such fact sheets will help Yukoners better understand the geochemistry of uranium and the uranium mining cycle, dissipating the apprehension over uranium exploration and facilitating a more detailed assessment of the uranium potential in the Yukon Territory.

Organization: Government of Yukon | Gouvernement du Yukon
Yukon Mineral Industry 1941-1959

This report was prepared to provide published information on the lode and placer mining industries in the Yukon during an important part of its history: mining and milling of Elsa and Keno Hill silver-lead ores had begun; significant nickel, copper, lead and zinc deposits were discovered in the White River, Vangorda Creek, and Macmillan Pass areas; and asbestos deposits were discovered.

Placer mining activity continued, although pressures in the form of rising costs, and stable gold prices were forcing the industry into decline. Both the lode and placer mining industries were affected during the war years by shortages of men and equipment, although there was a great deal of attention paid to sources of tungsten, a strategic mineral.

Records are not complete. Government office changes, lack of storage space and a warehouse fire may be some of the contributing factors..

Organization: Government of Yukon | Gouvernement du Yukon
Analyzing historic drilling data to investigate gold distribution on lower Hunker Creek and Klondike River

The Yukon Consolidated Gold Corporation (YCGC) tested, mined, and documented placer gold resources in the Dawson region from 1923 to 1965. The company was established to acquire the holdings of other dredging operations and smaller companies in the Klondike, and during the time it was active in Yukon, YCGC produced a robust collection of maps and textual documents including drilling results, dredge reserves, thawing and stripping layouts, and dredging limits.
This paper uses historic YCGC data to summarize gold distribution characteristics in Hunker Creek and builds upon previously published summaries of YCGC data. Attributes of 1005 YCGC drill holes and shafts along lower Hunker Creek and a short section of the Klondike River were digitized, compiled, and analyzed in a Geographical Information System (GIS). A raster analysis of the digitized data allows for interpretation and examination of surficial material thicknesses and gold distribution in the project area and identifies potential prospects for further exploration.

Organization: Government of Yukon | Gouvernement du Yukon
Regional stream sediment reconnaissance and trace element content of rock, soil and plant material in eastern Yukon Territory

Multi-element stream sediment reconnaissance in the Hess River region of the Eastern Yukon has outlined an extensive area characterized by anomalously high molybdenum values. An accessible region in the Hess Mountains, within the high molybdenum zone, was selected for detailed study of trace element levels in stream sediment, rock, soil and vegetation. In view of the frequently observed relationship between high forage molybdenum concentrations and the incidence of copper deficiency in cattle, molybdenum concentrations in plant species likely to be consumed by caribou and moose were of particular interest. High sediment molybdenum values are characteristic of catchments underlain by dark shales and less commonly dark limestone. These rocks and associated soils are rich in molybdenum. Concentrations in vegetation growing on anomalous shaly soils are characteristically low, while most plants growing on soils derived predominantly from limestone are molybdenum-rich. The Mo-Cu status of vegetation on limey soils is typically within the range associated with molybdenum induced hypocuprosis in cattle. Low molybdenum uptake by plants on soils derived from shales likely reflects the unavailability of the molybdate anion, resulting from its adsorption onto clay minerals and sesquioxides under acidic conditions prevalent in these soils. In neutral to mildly basic environments, typical of dark limestone soils, molybdenum adsorption is greatly decreased, and therefore molybdenum is relatively available to plants. In the detailed study area soil pH values are typically similar to pH levels in associated stream water. Therefore by combining stream sediment molybdenum concentrations with stream pH data, catchments likely to contain molybdenum-rich vegetation can be predicted. Unfortunately stream pH values were not obtained in the regional survey. In view of the apparent rarity of dark limestone throughout the Eastern Yukon, however, molybdenum-rich vegetation is not likely to be particularily widespread. Wildlife in this area, therefore, is probably not significantly affected by molybdenum induced copper deficiency.

Organization: Government of Yukon | Gouvernement du Yukon
High level terraces along Lower Stewart River and parts of Yukon River

Surficial geology mapping of the lower Stewart River valley has revealed sets of high level terraces formed when the paleo-Stewart River and the paleo-Yukon River were at higher base levels during the Pleistocene glaciations and during preglacial time. These terraces are composed of bedrock and a variety of gravelly alluvial fill, some of which are glacial in origin, others appear to be nonglacial in origin. The terraces are dominated by pebble and cobble gravel deposits which are typically covered by aeolian sand and silt deposits.

The age of these high level terraces was determined by paleosol development, height, and relationship to glacial limits. At best, these are crude correlations which serve to model drainage evolution. For example, inferences can be made about the aggradation of these main valleys. A regional base level was established possibly in late Tertiary time which is identified as a bedrock terrace level above the present flood plain level. The timing of this feature is probably older than White Channel gravel age (Pliocene-Early Pleistocene). Subsequent aggradation of valley fill gravel in the Stewart River drainage followed. The style of deposition is considered nonglacial for this highest alluvial surface. The main rivers incised their valleys due to a lowering of base level; perhaps due to tectonic uplift and/or isostatic readjustment subsequent to a long period of stability.

Placer gold distribution on the terraces appears to be widespread. Gold grains are typically flat, smooth and smaller than 1 mm. Gravel sampling of lithofacies was conducted on these high level terraces followed by concentration of heavy minerals by sluicing and panning. Gold is present on many of these terraces. Favourable targets for placer exploration may be in tributary valley terraces which grade to the main trunk stream high level terraces or basal gravel overlying bedrock. Erosion of outwash terraces is believed to contribute gold to modern bars along the Stewart River.

Organization: Government of Yukon | Gouvernement du Yukon
Sedimentology and hydrocarbon potential of fluvial strata in the Tantalus and Aksala formations, northern Whitehorse Trough, Yukon

Extensive conglomeratic strata in the Late Jurassic to Early Cretaceous Tantalus Formation were deposited in both shallow gravel-bed braided rivers, and deeper meandering gravel bed rivers. Overbank, marsh and swamp deposits, with potential to contain abundant terrestrial organic materials, are restricted to recessive intervals associated with small sandy and gravelly highconstructive river systems. Medium- to high-volatile bituminous and anthracitic coals in these intervals have limited potential as a source of additional gaseous hydrocarbons. Most of the conglomerates have a high fracture density, which would make them good reservoirs for coal-bed methane in settings where the Tantalus Formation lies beneath a seal of younger volcanic strata. Strata of the Late Norian Mandanna member of the Aksala formation near Takhini Hotsprings do not contain fluvial strata: laminated, bioturbated, intraclast-bearing red sandstones were deposited in an intertidal setting, and may have lost most of their organic material prior to burial.

Organization: Government of Yukon | Gouvernement du Yukon
Geology of northeastern Glenlyon area (NTS 105L/10, 13, 14, 15)

Mapping was carried out in the summer of 2018 by Rosie Cobbett and Halley Keevil for areas north of the Tintina fault; additional geological data provided by G. Jilson. Geology south of the Tintina fault is from YGS Open File 2002-9.

Two areas north of the Tintina fault are extensively thermally and hydrothermally altered.

The interpretation of fault traces through areas of poor rock exposure was guided by a Yukon wide geophysical survey of magnetic data.

Organization: Government of Yukon | Gouvernement du Yukon
Yukon Liquor Board Bylaws

The Yukon Liquor Board bylaws set out the rules and procedures the Board follows when carrying out its licensing and adjudicative responsibilities. These bylaws support the Board’s role as a quasi-judicial body by providing a transparent and consistent framework for decision-making, hearings, and appeals, and help ensure the Board operates independently and at arm’s length from the Yukon Liquor Corporation.

Organization: Government of Yukon | Gouvernement du Yukon
Unconformity-related uranium potential: clues from Wernecke Breccia, Yukon

Unconformity-related uranium deposits are best known from the Athabasca Basin, Canada and the Pine Creek area of Australia. In both regions, fault-controlled mineralization is associated with a regional unconformity between Paleo- to Mesoproterozoic clastic rocks and locally carbonaceous Paleoproterozoic metasedimentary rocks. A similar scenario exists in the Wernecke and Ogilvie Mountains of the Yukon where Mesoproterozoic Pinguicula Group strata unconformably overlie
Paleoproterozoic Wernecke Supergroup metasedimentary rocks. Uranium occurs in veins that cut Wernecke Supergroup rocks, most notably in association with Wernecke Breccia ¿ a large-scale Paleo- to Mesoproterozoic breccia system. Ages returned by uranium minerals are significantly younger than the ages of the host strata and may be reflecting mobilization of uranium during later tectonic and/or thermal events. The possibility that uranium occurrences in the Wernecke and Ogilvie mountains fit the unconformity model needs to be verified with further study, but is intriguing and raises the possibility that significant deposits may be found.

Organization: Government of Yukon | Gouvernement du Yukon
Assessment of Yukon regional stream sediment catchment basin and geochemical data quality

Stream catchment areas digitized from existing regional stream sediment sample locations are assessed for quality and confidence of sample site location, catchment surface area (used as a proxy for downstream dilution), surface material type, slope angle and slope aspect. Rankings for each of these attributes are combined into quality indices to give an overall impression of reliability for each catchment that can be incorporated into mineral exploration targeting criteria and design of further sampling programs. Data from quality control samples included with each sample batch during a recent re-analysis program are also assessed for some key elements. Standard reference materials included in two separate re-analysis campaigns show slight shifts in bias even though the same analytical method was used in both instances. Some elements, particularly Au, show an unacceptable amount of scatter in repeat analyses of the standard reference materials indicative of a non-homogenous distribution of Au in the materials for the small sample mass (0.5 g) used for analysis. Data precision is assessed using field and blind duplicate analyses for selected elements. The Au analyses show the poorest precisions, with data from Cu giving the best precision and data for As yielding intermediate precisions.

Organization: Government of Yukon | Gouvernement du Yukon