AndreaBozzo/ceres-open-data-index huggingface dataset:
Exploration Criteria for Gemstone Deposits and their Application to Yukon Geology

This report focuses on a selection of some of the most valuable gemstones in the global gem trade; ruby, sapphire, emerald, chrysoberyl, tsavorite garnet, tanzanite, and the gem minerals (topaz, aquamarine, tourmaline) found in pegmatites or rhyolites. Exploration criteria for other gemstones such as opal, nephrite jade, jadeite jade, zircon, lapis lazuli, and rhodonite are beyond the scope of this report.

For each gem mineral covered in this report, background information is introduced and the physical and chemical characteristics are presented. The geology and genesis of each gem deposit type is summarized and exploration guidelines listed. Because pegmatites are so closely associated with several gemstones including aquamarine, tourmaline and topaz, there is a chapter devoted to pegmatites and their gem minerals. Topaz rhyolite is a distinctive deposit type which is discussed in Chapter Eight. Application of the exploration criteria to Yukon geology is given in Chapter Nine. A reference list is provided for those readers who want to pursue further details.

Organization: Government of Yukon | Gouvernement du Yukon
2001–02 Supplementary estimates no. 3

Supplementary estimates no. 3 for the Government of Yukon 2001–02 Budget. 
This document was prepared by the Department of Finance under the direction of Management Board for the 1st Session of the 31st Legislature, Yukon Legislative Assembly. February 2002, Whitehorse, Yukon.

Organization: Government of Yukon | Gouvernement du Yukon
Cyanide - The Facts

Cyanide is probably one of the most universally recognized poisons. Cyanide contains a carbon atom connected to a nitrogen atom, hence the chemical formula CN. However, the term cyanide is used to refer to a wide array of chemicals containing cyanide. Cyanides can be manufactured (from ammonia and natural gas, or as a by-product of acrylic fibres and plastics production) but they also occur in nature.

Due to its toxic nature, cyanide has been used as a fumigant and poison since early time, however, its most familiar use in the Yukon is in the mining industry. Over 90% of the gold mined in Canada is extracted using a cyanidation process. Cyanide forms a very stable complex with several metals and has been used since 1887 to extract gold, silver, copper, zinc and molybdenum from ores.

Waste cyanide in tailings ponds and abandoned heap leach pads can be dealt with in several ways: natural degradation or attenuation, chemical degradation, hydrogen peroxide process, alkaline chlorination, sulphur dioxide-air oxidation, or microbial processes.

Long term adverse effects associated with mining sites are related primarily to metals rather than cyanide. Cyanide can naturally degrade rapidly in the environment by volatilizing to hydrogen cyanide gas (HCN). This gas is dangerous in a closed system but much less so when gradually released in an out-of-doors environment.

The toxicity of cyanide is very dependent on its form. Mine effluents, tailings and leach pond water can contain cyanide in many forms ranging from the cyanide ion to strong metal cyanide complexes. The toxicity of cyanide compounds depends on the compound's ability to release the cyanide.

Each mine in the Yukon must abide by a Water Licence issued by the Yukon Territory Water Board. The licence ha standards of cyanide concentration that must be met in the effluent before it is discharged to the receiving environment.

Organization: Government of Yukon | Gouvernement du Yukon
Evaluation of the origins of gold hosted by the conglomerates of the Indian River formation, Yukon, using a combined sedimentological and mineralogical approach.

Conglomerates belonging to the Indian River formation (IRF), south of the Klondike goldfield, have recently become the focus of exploration activity owing to their potential as hosts for paleoplacer gold derived from the Klondike. However, textures within the conglomerate have been interpreted as indicative of hydrothermal activity, and the possibility exists of in situ epithermal gold.
Paleocurrents in conglomerates indicate dominant transport from the southeast, incompatible with gold transport from the Klondike. Gold grains from unconsolidated conglomerate at Montana Creek reveal an epithermal signature (20-50% Ag, 0.3 to 3% Hg and opaque inclusion suite containing complex polymetallic sulphotellurides and sulphosalts), distinct from the signature of placer and lode sources in the central and southern Klondike (12-20% Ag, Hg absent and opaque inclusion suite of simple base metal sulphides). Gold grain morphology and alteration textures within unconsolidated conglomerates suggests that Montana Creek gold is derived from in situ epithermal mineralization related to that previously reported at Eureka Dome.

Organization: Government of Yukon | Gouvernement du Yukon
2012–13 Supplementary estimates no. 1

Supplementary estimates no. 1 for the Government of Yukon 2012–13 Budget. 
This document was prepared by the Department of Finance under the direction of Management Board for the 1st Session of the 33rd Legislature, Yukon Legislative Assembly. October 2012, Whitehorse, Yukon.

Organization: Government of Yukon | Gouvernement du Yukon
Wolf Lake project: Revision mapping of Dorsey Terrane assemblages in the upper Swift River area, southern Yukon and northern B.C.

The northern half of the Jennings River (104O) and southern half of the Wolf Lake (105B) map areas include polydeformed and metamorphosed rocks of the eastern Big Salmon Complex (Yukon-Tanana Terrane) and a succession of mostly Paleozoic rock assemblages currently grouped in Dorsey Terrane.

On the northeast side of Dorsey Terrane, siliceous grits and mafic metavolcanic rocks of the Dorsey assemblage are thrust over the Ram Creek assemblage. Dorsey assemblage is in turn structurally overlain by thin mafic volcanic rocks and limestone (Klinkit (?) assemblage), and by dark phyllitic rocks and quartzites of the Swift River assemblage.

Extensive stratabound pyrrhotite-sphalerite mineralization occurs along a 6.5 km structural trend in calc-silicate rocks and rhyolite of the Ram Creek assemblage. Similar mineralization also occurs several kilometres southwest of that trend, within or adjacent to the Dorsey assemblage. Both assemblages contain quartz +/- feldspar -phyric layers with potential for volcanogenic massive sulphide showings.

Organization: Government of Yukon | Gouvernement du Yukon
The mineralogy and geochemistry of polymetallic mineral deposits at the Ketza River gold mine, Pelly Mountains, central Yukon Territory

The Ketza River polymetallic mineral deposits are situated in the Pelly Mountains, Central Yukon Territory. The deposits were mined for gold from 1988 to 1990, producing 400 tomes of oxide ore per day over that period. The Ketza River deposits are hosted by lower Paleozoic sedimentary strata of the parautochthonous Cassiar Terrane. The main host to economic mineralisation is a lower Cambrian, massive, areheocyathid-bearing limestone, which outcrops over much of the Ketza River area. Four styles of mineralisation are recognised within the Ketza River deposits. Type I mineralisation occurs in the centre of the area and consists of argillite-hosted, Au- quartz-sulphide veins. Sulphide mineralogy is mainly arsenopyrite and pyrite. Type II mineralisation consists of limestone-hosted, massive sulphide mantos and chimneys. The principal sulphide mineralogy of the mantos is pyrrhotite-arsenopyrite-pyrite-chalcopyrite, with quartz and calcite gangue. Gold is present within the arsenopyrite and pyrite. Type III mineralisation consists of limestone-hosted, quartz-sulphide veins and mantos. Mineralogy is similar to the Type II mineralisation, but contains a higher proportion of gangue. Type IV mineralisation consists of Ag-Pb veins. These veins are hosted by a variety of lithologies and represent the outermost extent of Ketza River mineralisation. Sulphide mineralogy is galena-sphalerite-pyrite, with siderite, calcite and quartz gangue. Oxidation of sulphides in parts of the Ketza River area is deep and pervasive. Areas of oxidation show increased gold grade and were the focus for mining. Oxidation occurs in the heavily fractured central area of the mineralisation, and along the Peel Fault, which extends from the centre of mineralisation towards the east. Light stable isotope studies indicate that the main mineralising fluid was of meteoric origin (delta (18)Ofluid = 10 per mil, delta Dfluid = -165 per mil). This fluid had evolved in delta (18)O by interaction with Cassiar Terrane rocks before mineralisation occured. Fluid flow in the limestones was pervasive, and produced a large, approximately 75km(2), (18)O depletion halo around the deposits. The later oxidising fluid was also of meteoric origin (delta (18)Ofluid = 18 per mil) but shows no evidence of interaction with the sedimentary pile. Fluid inclusion microthermometry suggests that the temperature of formation of the deposit was around 325 degrees C, at pressures above 600 bars. The mineralising fluid contained approximately 11 mole% CO2+ or -CH4, and 5 equivalent weight% NaCI.

Organization: Government of Yukon | Gouvernement du Yukon
Development of Wernecke breccia in Slats Creek (106 D/16) map area, Wernecke Mountains, Yukon

Wernecke breccia comprises numerous intrusive hematitic breccia zones exposed in the Wernecke and Ogilvie mountains of central Yukon. The breccias were emplaced in Middle Proterozoic time into Middle Proterozoic strata of Wernecke Supergroup, Fifteenmile group, and possibly Pinguicula group. Significant mineralization of Cu, U, Co, Ag and Au within and near breccia zones occurred during widespread Fe, CO2, and Si metasomatism. Following a period of hydrothermal activity and intense fracturing, breccia zones in the study area were generated in open spaces produced by extensional faulting or rapid expansion of volatile-rich fluids. A strong spatial correlation between breccia and crosscutting mafic to felsic intrusions indicates a magmatic linkage. Metasomatism extended from before brecciation to after cooling of the igneous intrusions. The metasomatising fluids may have been partly derived from residual liquids of possible tholeiitic magma chambers fractionating at depth. Regional deformation and metamorphism incurred during Racklan orogeny in Middle Proterozoic time preceded brecciation; the breccias developed in fully lithified rock. Previous models of breccia genesis invoking evaporite or mud diapirism are considered invalid.

Organization: Government of Yukon | Gouvernement du Yukon
Airborne multisensor geophysical survey, Minto area, Yukon

Results of a multisensor (gamma ray spectrometer, magnetometer) helicopter survey flown July-September, 2001, in the Minto area, Yukon, are available in a variety of digital and printed formats. This is a joint release from the Geological Survey of Canada (GSC) and the Yukon Exploration and Geological Services Division (EGSD). Flight lines were positioned every 500 m. The survey was funded by the Government of Yukon.


Organization: Government of Yukon | Gouvernement du Yukon
The co-variation of lithology and geometry in Triassic reefal limestones at Lime Peak, Yukon

Lime Peak is an Upper Triassic carbonate complex approximately 40 km northeast of Whitehorse. It is one of many carbonate buildups in the Whitehorse Trough which occur as isolated lenses surrounded by Triassic greywacke and volcanic-clast conglomerates derived from an arc to the southwest. The carbonates at Lime Peak are particularly well-exposed and have been shown to be a series of organic reefs which shed debris into surrounding inter-reef areas.

Fieldwork at Lime Peak in 1980 established the existence of massive reefal limestones occurring in 3 distinct forms. The variability of both the geometry and the lithology of the massive limestones was observed in 1980 but was not studied in detail. Considerable effort was spent in 1981 mapping lithology in order to establish the nature and extent of organic framework in the reefal bodies and to develop an explanation for the three distinct growth forms.

Organization: Government of Yukon | Gouvernement du Yukon
Geology and mineral occurrences of Sprague Creek map area (115P/15), western Selwyn Basin

Sprague Creek map area is underlain by multiply deformed Upper Proterozoic to mid-Paleozoic metasedimentary rocks and undeformed Cretaceous felsic intrusions. The oldest and structurally deepest rocks underlie most of the southern two-thirds of the map area. Three phases of regional deformation and a younger suite of faults and fractures are represented in Sprague Creek map area.

Mineral occurrences in the area comprise veins, breccias, and skarns spatially and probably genetically related to Cretaceous intrusions, and gossanous breccias along NNW-trending lineaments.

Organization: Government of Yukon | Gouvernement du Yukon
McMillan property, southeastern Yukon

The McMillan deposit contains 1.1 million tonnes grading 8.3% Zn, 4.1% Pb and 62 g/t Ag in a manto-like replacement deposit in the Proterozoic/Lower Cambrian Hyland Group at the sheared contact between carbonate rocks and underlying shale. A smaller deposit to the south contains a further 0.4 million tonnes grading 9.3% Pb, 1.7% Zn and 214 g/t Ag. These deposits appear to lie in the footwall of a southward-dipping thrust fault which extends eastward toward the Hyland Gold property.

Organization: Government of Yukon | Gouvernement du Yukon
Geology of Carcross (105D/2) and Part of Robinson (105D/7) Map Areas

Geology of the Carcross (105D/2) and part of the Robinson (105D/7) map areas, south of Whitehorse, Yukon, were mapped at 1:50,000 scale during the 1988 field season. The map areas are within the Teslin Plateau and Boundary Ranges physiographic regions.

Rocks of the Atlin (Cache Creek) Terrane, Whitehorse Trough and Coast Plutonic Complex are each represented in the study area. The Atlin Terrane is bounded by the Nahlin thrust fault and the Crag Lake tear fault. The Nahlin Fault is westerly verging and was active during Late Cretaceous time.

The westernmost exposures of Whitehorse Trough strata are those of the structurally complex Tally Ho Shear Zone, the northern extension of the Llewellyn Fault. This structure invovles rocks as young as Cretaceous.

Two ages of Cretaceous volcanic activity are represented by the Carmacks and Mount Nansen Groups. Rocks of the Montana Mountain volcanic complex are early Late Cretaceous in age (88-99 Ma).

Mineral occurrences of the Montana Mountain area are at least as young as Paleocene and are related to the Nahlin Fault. Other mineral occurrences in the area are spatially related to the Tally Ho Shear Zone.

Organization: Government of Yukon | Gouvernement du Yukon
Palaeoenvironment, palaeohydrography and chemostratigraphic zonation of the Canol Formation, Richardson Mountains, north Yukon

Sedimentological and geochemical results from samples in the Richardson Mountains indicate that siliceous shales and chert of the Canol Formation were deposited in stratified, oxygen-depleted waters that favoured the preservation of organic matter. Dilution by terrigenous input was minimal; however, fluctuating palaeoproductivity resulted in significant biogenic silica enrichment that reduced porosity. The Canol Formation was divided into four regionally correlatable chemostratigraphic zones. Each zone was characterized by up-section profiles of: decreasing biogenic silica enrichment, increasing proportions of siliceous shale relative to chert, decreasing redox-sensitive Mo, U and V enrichment factors and decreasing Mo/TOC (total organic carbon) ratios. A preliminary sequence stratigraphic framework was constructed and eustasy invoked as the dominant allogenic control. Mo/TOC ratios are indicative of a silled, restricted basin with euxinic deepwater. The overall decrease up-section of these ratios suggests increasing restriction over time, associated with relative sea-level fall. Comparison of north Yukon data with similar modern and ancient basins has constrained preliminary reconstructions of Canol basin palaeohydrography.

Organization: Government of Yukon | Gouvernement du Yukon
2008–09 Supplementary estimates no. 2

Supplementary estimates no. 2 for the Government of Yukon 2008–09 Budget. 
This document was prepared by the Department of Finance under the direction of Management Board for the 1st Session of the 32nd Legislature, Yukon Legislative Assembly. March 2009, Whitehorse, Yukon.

Organization: Government of Yukon | Gouvernement du Yukon
Yukon Placer Mining Industry 1978-1982

This volume contains reports describing the placer mining industry in Yukon during 1978 to 1982 and follows earlier annual Mineral Industry Reports for Yukon published by the Department of Indian and Northern Affairs, and by the Geological Survey of Canada.

There are two sections in this volume. The first contains reports describing certain aspects of the placer mining industry, while the second contains maps showing the distribution of placer claims and leases, and descriptions of individual mining operations.

Reports in the first section describe the placer mining industry as a whole, and outline regulations and restrictions on placer mining in Yukon. In addition, lists of references to selected creeks in Yukon are also included. Several papers describe the formation of placer deposits, and the exploration mining and marketing of placer gold.

Reports in the second section describe 288 individual mining operations active in Yukon between 1978 and 1982. Information in the reports was derived from field investigations, from records on file, and some information for the years 1978 to 1979 was compiled from the field notes of Dr. D.B. Craig.

Organization: Government of Yukon | Gouvernement du Yukon
Light Auger Drilling for Placer Prospecting in the Klondike District, Yukon; a Pilot Project

In unconsolidated material, penetration rates for the all-terrain-vehicle (ATV) drill ranged from 3 ft/hr (0.9 m/hr) in frozen sandy pebble/cobble gravel to 33 ft/hr (10 m/hr) in unfrozen, loose muck. Drilling penetration was influenced by: 1) extent of freezing, 2) clast size, 3) distribution of clast size, and 4) degree of cohesiveness. Out of twenty-three holes, twelve reached bedrock and thirteen were gold-bearing. Maximum drill hole depth reached was 36 ft (11 m). Eleven holes were drilled adjacent to previously drilled larger diameter holes for gold value correlations. Six of these holes were known to be gold-bearing; our drilling indicated the presence of gold in five out of six holes. Small gold particles recovered from our drilling have a variety of shapes which range in size from 0.1 mm to 2 mm.

The ATV drill rig field tested in this study met most of the objectives of this project but gave mixed results. The ATV drill rig:
- is limited to terrain of relatively smooth microtopography
- is helicopter transportable but requires a medium sized helicopter
- can penetrate most surficial materials found in typical Klondike placer deposits except for coarse gravels and some frozen gravels
- is an acceptable tool for studying the general stratigraphy of Yukon placer deposits, although vertical sections are more representative of stratigraphy
- can detect the presence of gold in penetrable stratigraphy
- recovered gold from virtually every gold-bearing hole previously drilled by larger drill rigs but gold values were not as accurate as results from larger diameter drilling.

This particular ATV drill rig is limited by an old technological design and worn mechanical components which make it unsuitable for future projects of similar nature. However, the results of this project demonstrate that light weight and portable auger drilling has potential as a prospecting tool, particularly in drainage basins with limited geoscientific informaton and/or placer mining history.

Organization: Government of Yukon | Gouvernement du Yukon
Bedrock geology at the boundary between Yukon-Tanana and Cassiar terranes, Truitt Creek map area (NTS 105L/1), south-central Yukon

The Tummel fault zone, a northwest-trending belt of rocks of uncertain age and/or tectonic affinity, separates Paleozoic miogeoclinal strata of Cassiar Terrane from Yukon-Tanana Terrane metavolcanic and metasedimentary rocks. Northeast of the fault, Cassiar Terrane comprises pelitic and semipelitic rocks with rare amphibolite, which are correlated with the Kechika Group. These are overlain by carbonate correlated with the Askin Group. Southwest of the fault, in Yukon-Tanana Terrane, Devono-Mississippian siliciclastic rocks are overlain by Mississippian arc volcanic rocks. Granodiorite and diorite of the Telegraph Plutonic Suite (348-350 Ma) intrude the siliciclastic rocks. Foliated greenstone, leucogabbro intrusions, serpentinite and chert occur in the Tummel fault zone. The Early Cretaceous Glenlyon Batholith intrudes strata of Cassiar Terrane. Contact metamorphism recognized across the Tummel fault zone is interpreted to have been imposed by the Glenlyon Batholith. If correct, this interpretation requires that post-mid-Cretaceous displacement across the Tummel fault zone has been minimal (~5 km).

Organization: Government of Yukon | Gouvernement du Yukon
Isotopic identification of subglacial processes

A comprehensive stable isotope study of basal ice and debris layers in two Yukon surging glaciers suggests an isotopically variable basal freezing cycle. Trapridge and Backe glaciers, St. Elias Range, Yukon, have parallel basal debris layers that extend for hundreds of metres along marginal ice faces and in meltwater tunnels. Both glaciers are subpolar surging glaciers that surge on a cycle of 40-50 years. They are approximately 5 km long and 1 km wide with a lower ablation zone that is frozen to the bed and an upper accumulation zone that has basal ice at the pressure melting temperature.

Organization: Government of Yukon | Gouvernement du Yukon
U-Pb age, whole-rock geochemistry and radiogenic isotopic compositions of late Cretaceous volcanic rocks in the central aishihik lake area, Yukon (NTS 115H)

Geochemical, isotopic and U-Pb dating studies of volcanic rocks of the Tlansanlin Formation in central Aishihik Lake map area (115H) show that these are Late Cretaceous (75.8 ± 0.4 Ma to 77.3 ± 1.3 Ma), relatively primitive magmas that were emplaced in a continental arc setting. Intrusive rocks in the immediate area, associated with the Hopper porphyry and skarn and Sato porphyry occurrences (Yukon MINFILE 115H 019, 021, respectively), are similar in age and composition to the Tlansanlin Formation rock units, confirming the presence of a significant Late Cretaceous igneous and mineralizing event in the area. Significant porphyry and skarn occurrences associated with the Late Cretaceous intrusions in the Aishihik Lake area, as well as the important mineral deposits and occurrences associated with this magmatic event in the Dawson Range to the northeast (e.g., Casino, Revenue-Nucleus, Sonora Gulch), underscore the metallogenic potential of this previously poorly recognized magmatic event.

Organization: Government of Yukon | Gouvernement du Yukon
2024 Wildland fire management bulletins

Archived wildfire bulletins from 2024. See [current wildfire bulletins on Yukon.ca](https://yukon.ca/blogs/wildfire-bulletins).

Visit the Yukon's [Wildfires hub](https://wildfires.service.yukon.ca/) or the [text-only updates page](https://yukon.ca/en/emergencies-and-safety/wildfires/get-text-only-wildfire-updates) to get more information about current wildfire conditions in the Yukon.

Organization: Government of Yukon | Gouvernement du Yukon