AndreaBozzo/ceres-open-data-index huggingface dataset:
Hydrothermal modelling of Takhini Hot Springs (NTS 105D/14)

The Takhini Hot Springs, located northeast of Whitehorse, Yukon, exhibits significant geothermal potential with a surface water temperature of 46°C. To address the limited geological knowledge in the region, a 500 m deep well was strategically drilled in this area and intercepted warm groundwater (25°C) at a depth of 450 m. The objective of this study was to assess the geothermal potential of the Takhini Hot Springs area using 2D subsurface flow and heat transfer simulations to numerically replicate the observed temperature and gain a better understanding of heat transfer mechanisms affecting the geothermal resource. Inclined permeable layers such as contacts between fractured sedimentary units appear to facilitate groundwater circulation, creating a path for geothermal fluids to rise. A fault that is assumed to be subvertical is present in the area but does not impact the model’s water circulation. A sensitivity analysis was conducted to define the impact of each model parameter on the hot springs temperature and on temperature profiles simulated in the Takhini well. The analysis revealed that boundary conditions, including basal heat flux and surface recharge, as well as rock thermal conductivity and permeability, are the most influential parameters in the model.

Organization: Government of Yukon | Gouvernement du Yukon
Natural Source Contaminants in the Yukon: Focus on Selenium

This report is a product of the continuation of a study begun in 2007/08. The 2007/08 report focused on selenium concentrations and pathways in the aquatic ecosystems of various tributaries of the Francis, Finlayson and Pelly rivers, which drain portions of the Yukon Tanana-Terrane and Cassiar Platform between Ross River and Watson Lake. In 2008/09 the sampling program was expanded to another area of the Yukon that is recognized as being highly mineralized: areas within the Selwyn Basin. The 2008/09 study area is located along the North Canol Road, northeast of Ross River.

Organization: Government of Yukon | Gouvernement du Yukon
Paleoproterozoic Bonnet Plume River intrusions: Evidence for a calc-alkaline arc at 1.7 Ga and its partial preservation in Yukon, Canada.

The 1.71 Ga Bonnet Plume River intrusions (BPRI) and related volcanics are preserved only as clasts in the 1.60 Ga Wernecke breccias of Yukon that host iron-oxide copper gold (IOCG) occurrences. Field work conducted in 2009 confirmed that they did not intrude the surrounding <1.64 Ga Wernecke Supergroup. Petrography shows that they are extensively altered and/or metasomatized, although relicts of primary igneous minerals remain. The major oxides are of little use in classification. Trace element geochemistry however, reveals a mafic to intermediate, calc-alkaline volcanic arc signature. Geochemical modelling has demonstrated that crystal fractionation was dominated by pyroxenes, plagioclase and olivine. The BPRI and related volcanic rocks are thought to have originated in a calc-alkaline volcanic arc that was obducted onto the Wernecke Supergroup, subsequently partially brecciated, and finally sank within the Wernecke breccias to the level of the Wernecke Supergroup.

Organization: Government of Yukon | Gouvernement du Yukon
Structure and Stratigraphy of the MacMillan Fold Belt: Evidence for Devonian Faulting

This study describes the structural and stratigraphic setting of Devonian bedded barite and sedimentary exhalative lead-zinc-silver-barite deposits near MacMillan Pass in eastern Yukon. It shows that the deposits occur within MacMillan Fold Belt, an anomalous west-trending feature made up of three parallel elongate domains called the North, Central and South Blocks. Each is characterized by distinctive styles of deformation and Devonian strata.

The north Block is characterized by a thick Early and Middle Devonian chert and shale sequence included in the Lower Earn Group and by an intricate array of southerly directed thrust faults. The Central Block includes unusually thick Early and Middle Devonian silty limestone intercalated with volcanic and volcaniclastic rocks within the upper part of the Road River Group. The Tom and Jason sedimentary exhalative zinc-lead-silver-barite deposits are associated with a thick sequence of coarse clastic rocks thought to belong to a submarine fan complex within the Lower Earn Group. Tight upright folds, high angle reverse faults and irregularly oriented faults are characteristic.

In the South Block, the Lower Earn Group comprises a thin Devonian shale sequence. Open upright folds and few faults are the structural style. The differences in Devonian strata and contrasting style of deformation between blocks may reflect older (Devonian?) fault control to depositional patterns, but structures of that age have not been identified.

Organization: Government of Yukon | Gouvernement du Yukon
Preliminary description and slope stability analyses of the 2008 Little Salmon Lake and 2007 Mt. Steele landslides, Yukon

In August 2008, reactivation of the Little Salmon Lake landslide occurred. During this event, hundreds of conical mounds of variable size and composition formed in the deposition zone. The characteristics of these landforms are described and a potential mechanism for their formation is proposed. A preliminary slope stability analysis of the 2007 Mount Steele rock and ice avalanche was also undertaken. The orientation of very high persistence (>20 m long) structural planes (e.g., faults, joints and bedding) within bedrock in the source zone was obtained using an airborne-LiDAR digital elevation model and the software COLTOP-3D. Using these discontinuity orientation measurements, kinematic, surface wedge and simple three-dimensional distinct element slope stability analyses were performed.

Organization: Government of Yukon | Gouvernement du Yukon
Shape and Composition of Lode and Placer Gold from the Klondike District, Yukon, Canada (115O Parts of 116 B)

We have determined the major and trace element composition of approximately 2700 gold particles from 21 gold-bearing mesothermal quartz veins and 35 placer gold samples from the Klondike District in western Yukon Territory. Measured Au, Ag, Cu, and Hg contents were used to define a characteristic geochemical signature for each of the vein samples. These signatures were then compared with the various compositional populations that we have distinguished within each of the placer samples. Preliminary conclusions derived from the study include: 1) placer gold in both recent stream deposits and in the Plio-Pleistocene White Channel Gravels is detrital in origin; 2) the placer gold is mainly, if not entirely, derived from mesothermal quartz veins; 3) all lode sources for the placer gold have not yet been located; and 4) composition data can be used to link placer gold to its specific lode source.

Organization: Government of Yukon | Gouvernement du Yukon
Yukon Platinum Occurrences & Potential

Geological map (1:1,000,000 scale) of the Yukon Territory, including platinum potential, platinum occurrences, a list of selected geological units with PGE potential, density of geochemical anomalies for nickel, chromium and cobalt and selected stream silt anomalies for nickel, cobalt and chromium.

Accompanying the map is a brief report describing: Yukon MINFILE occurrences with reported PGE mineralization and anomalies; interpretation of regional silt geochemical anomalies; placer PGEs in Yukon; gravity anomalies; and PGE potential in Yukon (concepts and localities).

Organization: Government of Yukon | Gouvernement du Yukon
Heap Leaching Grade and Metallurgical Evaluation of White Channel Gravel

Twenty-five White Channel gravel samples were processed in order to estimate the gold content. Selected samples were used to determine the viability of gold extraction by heap leaching.

Gold levels ranged from <0.03 to 0.33 g/t, and averaged 0.08 g/t. Pre-concentration of the gold by screening at 4 mesh was successful in upgrading gold levels by an average of 2.4 times, without gold loss. The average grade of the -4 mesh product was 0.19 g/t Au.

Use of gravity concentration principally as an analytical method (i.e., to upgrade gold for more reliable analysis) and, secondly, as a potential processing method, was not successful as only three samples yielded high gold recoveries.

Metallurgical evaluation of selected samples was completed. Bottle rolls and column tests with cyanide yielded maximum gold extractions of greater than 65%. Cyanide consumptions were less than 1.2 kg/t of leach feed. More testwork is required to confirm extractions and to further develop agglomeration procedures.

Sampling was a problem due to the low grade of the material and the discrete nature of the gold particles, which may result in the heterogenous segregation of the gold during the sampling and assay procedures. These effects are more commonly known as the "nugget" effect. A more suitable method of assaying the feed would be to leach the material with cyanide, and calculate a head assay from the leach products.

Organization: Government of Yukon | Gouvernement du Yukon
2017–18 Supplementary estimates no. 2

Supplementary estimates no. 2 for the Government of Yukon 2017–18 Budget. 
This document was prepared by the Department of Finance under the direction of Management Board for the 2nd Session of the 34th Legislature, Yukon Legislative Assembly. March 2018, Whitehorse, Yukon.

Organization: Government of Yukon | Gouvernement du Yukon
NH4 geochemistry near sedimentary exhalative deposits in Selwyn Basin: A possible exploration tool

Studies conducted on two Alaskan shale-hosted stratiform Pb-Zn-Ag deposits showed that the NH4 content of illites increased toward the ore bodies and might be used as an exploration tool. This study compares the NH4 chemistry of five shale-hosted stratiform deposits in Selwyn Basin and verifies the existence of a halo near some.

The five are: Howards Pass, Driftpile (Gataga District), Clear Lake, Tom, and Jason (Macmillan Pass). NH4 was found in feldspars, but not in illites. This is probably due to a transferral of NH4 from illites to authigenic feldspars during regional metamorphism. NH4 in feldspars was found to increase in the hangingwall over the Howards Pass and Clear Lake deposits. Concentrations reached as high as 2000 ppm. Evidence suggests that NH4 halos around the other deposits were disturbed by detrital input.

The NH4 anomalies near deposits in Selwyn Basin resemble those near active hydrothermal systems in the Guaymas Basin, Gulf of California - a modern analogous rift basin. A model is proposed for the formation of an NH4 halo.

Organization: Government of Yukon | Gouvernement du Yukon
Petroleum Resource Assessment, Eagle Plain Basin and Environs, Yukon Territory Canada

The Eagle Plain basin and its environs is a potentially prospective petroleum province in Yukon. Extensive initial exploration in this area, focused on discovering crude oil, identified 83.7 Bcf of natural gas and 11.05 MMbbls of crude oil, throughout the succession and across the geographic extent of the basin. This study differs significantly from previous estimates of undiscovered potential, which were less optimistic. Intriguing plays exist associated with the stratigraphic opportunities for entrapment in Paleozoic carbonates against the Richardson Trough, but these appear to be higher risk/reward targets than the continued exploration of the uppermost Paleozoic succession. Additional conceptual play concepts, including those in the Devonian Imperial and Jurassic Porcupine River formations, which have indications of petroleum occurrence, were not quantitatively assessed.

Organization: Government of Yukon | Gouvernement du Yukon
The Origin and Setting of Anomalous Arc Magmatism in the Wrangell Volcanic Belt, Southwest Yukon

In the Wrangell Volcanic Belt (WVB) a northwesterly increase in volume of calc-alkaline versus transitional (sodic alkaline/calc-alkaline) magmatism is accompanied by a migration in the locus of magmatic activity. The space-time-composition relationships reflect oblique convergence between the North American and Pacific plates over the last 17.3 million years. Compositional- temporal trends are particularly well preserved in the four stages of volcanic stratigraphy in the St. Clare Creek field (17.3-6.5 Ma). Initially, alkaline olivine basalts, hawaiites and mugearites were erupted from small, isolated shield volcanoes in the axis of a continental molasse basin. The alkaline lavas were followed by an early stratovolcano stage of transitional trachybasalts and high-Fe basaltic trachyandesites, succeeded by basaltic trachyandesites, trachyandesites, trachytes, rhyolites and rare basaltic andesites. Widespread basaltic fissure eruptions dominated the third volcanic stage. The late stratovolcano stage consisted of renewed eruption of intermediate and felsic transitional lavas. A systematic temporal-chemical relationship between early alkaline and younger transitional and calc-alkaline lavas in the St. Clare Group is illustrated by a decrease in FeO/MgO, Na+K/Si, NB/Zr/Y, and an increase in Rb/Zr with increasing stratigraphic levels. Primitive basalts are non-primary and show variable degrees of fractionation between large ion lithophile (LILE) and high field strength element abundances. A model is proposed in which the alkaline shield volcano and early stratovolcano stage magmas formed by progressive melting of a rising mantle diapir in response to local extension along the Duke River fault. Early Fe-rich magmas may have undergone clinopyroxene fractionation at high pressures, but most magmas appear to have differentiated in the near surface environment via fractional crystallization and local magma mixing. With the onset of Yakutat subduction, progressively larger amounts of slab-derived, LILE-enriched fluids metasomatised overlying peridotite, which in turn melted to form primitive, late-stratovolcano stage magmas.

Organization: Government of Yukon | Gouvernement du Yukon
Evidence for limited glaciation in northern Kluane Range, southwestern Yukon, with implications for surficial geochemical exploration

Preliminary investigation of surficial geology in northern Kluane Range has resulted in new interpretations of Pleistocene ice cover including extensive unglaciated terrain and restricted glaciation during the Last Glacial Maximum. Two glacial limits are identified: a higher limit recording the most extensive glaciation of the area; and a lower limit that records younger, less extensive glaciation. This paper describes Pleistocene limits of the Donjek Glacier and the distribution of surficial materials in the upper Quill, Maple, and Wade creek drainages. The source and transport mechanism of surface materials has particular significance for surficial geochemistry sampling programs and implications for mineral exploration are addressed.

Organization: Government of Yukon | Gouvernement du Yukon
The geology of the Rapid Creek-Big Fish River phosphatic iron formation Northern Richardson Mountains, Yukon

The phosphatic iron formation under investigation shows some interesting characteristics. Aspects that set it apart from other phosphatic iron formations are: 1) coexistence of abundant phosphorus and iron, 2) high paleolatitude of formation, 3) location in a tectonically active environment, 4) occurrence of high temperature minerals in an area of relatively low metamorphic grade, and 5) dominance of the minerals satterlyite and arrojadite.

Geochemical analysis, paleontological studies and petrographical analysis were undertaken to characterize this deposit. As well, stratigraphic relationships in the phosphatic iron formation were investigated.

Organization: Government of Yukon | Gouvernement du Yukon
Geology of the Guano-Guayes rare earth element bearing skarn property, Pelly Mountains, Yukon Territory

The Guano-Guayes property, in the Pelly Mountains of Yukon, covers a rare earth element (REE) bearing contact metamorphic aureole which developed around a syenite stock during Mississippian time. Sedimentary rocks consist of several hundred metres of Ordovician dark gray shale which are faulted upward adjacent to Silurian interbedded impure calcite and dolomite marbles and quartzites overlain by Silurain quartzite. Sedimentary rocks are on the steeply, west-dipping limb of a regional anticline. The syenite, at the southeast end of a northwest-trending belt of syenite stocks and associated volcanic rocks, consists of 40 to 90 percent orthoclase in laths up to several cm long, and of up to 60 percent mafic minerals now mostly altered to biotite. Rare earth element values of syenite, when normalized to chondritic values, have a crustal pattern with magnitude slightly higher than that of crustal rocks. Dikes, believed to be cogenetic with syenite, intrude sedimentary rocks within and inear the contact metamorphic aureole. These dikes are dark-coloured and originally contained up to 25 percent zircon (now partly altered to secondary minerals). Zircon is enriched in total REE and relatively enriched in light REE compared to syenite, probably due to selective partitioning of REE. REE patterns in skarn and sedimentary rocks suggest that fluids circulated through syenite and carried trace amounts of REE from it into the skarn. There was no significant movement of REE from dikes into skarn or sedimentary rocks. Contact metamorphic rocks can be divided into three units: quartz-muscovite hornfels, dark green diopsade-calcite-phlogopite-tremdlite-sphene skarn, and light green diopside-calcite-phlogopite skarn. Depth at time of intrusion of syenite, as estimated from regional geologic contraints, was around 1 to 2 km (circa 500 bars). Parageneses and textures observed in thin section in contact metamorphic rocks indicate that prograde metamorphism at this pressure reached a maximum temperature of 450 to 540 degrees C, with heat being transferred from the intrusive dominantly by fluids. The mole fraction of CO2 in metamorphic fluids, increased By the liberation of CO2 during prograde metamorphic reactions, was moderate. Large amounts of Fe, Mg, and possibly Si02, were added to the skarn. Retrograde metamorphism involved significant addition of water to the system, proven by the appearance of secondary epidote, chlorite, and, later, serpentine. Extensive retrograde metamorphism accompanied by large-scale migration of elements through syenite ended 206 ±15 Ma ago (syenite whole-rock isochron) and the last resetting event took place between 156 ± 5 Ma (K-Ar date on biotite-altered arfvedsonite) and 128 ± 25 Ma (syenite mineral isochron). Petrology, geochronometry, and rare earth element studies presented here have contributed to an understanding of the genesis of syenite, skarn, and mineralized dikes within the Guano-Guayes area.

Organization: Government of Yukon | Gouvernement du Yukon
Nickel-Copper-Sulphide Deposits in Kluane Ranges, Yukon (Parts of 115F, 115G)

A sequence of Permo-Triassic rocks within a 260 square kilometre part of the Kluane Ranges, southwestern Yukon, consists of Lower Permian volcaniclastic and sedimentary rocks, disconformably overlain by upper Triassic amygdaloidal volcanic rocks. Mafic to ultramafic rocks occur within the upper part of the Permian section and in the Triassic flows. Folding and faulting of this sequence is intense.

The ultramafic rocks are peridotite-dunite complexes in the form of sills. Some gabbroic bodies have intruded along sill boundaries, but most are separate sills or dykes. Nowhere have they been found cutting rocks younger than the upper Triassic volcanics.

Ni-Cu mineralization is spatially associated with the gabbros and peridotites. Dunite portions of ultramafic complexes are barren. Sulphide minerals include pyrrhotite, pentlandite and chalcopyrite, locally with pyrite, sphalerite and galena. Occurrences are classified as follows::

1. Massive to stringer within country rock adjacent to gabbro intruding peridotite.
2. Massive to heavily disseminated at the country rock contact of gabbro intruding peridotite.
3. A) Heavily disseminated to nearly massive within gabbro intruding peridotite.
B) Disseminated within separate gabbroic bodies.
4. Very weakly disseminated within peridotite.

The mineralized gabbro-ultramafic intrusions are spatially related to the Triassic volcanic flows. The mafic and ultramafic rocks, their Ni-Cu deposits, and volcanic flows are believed to be related genetically.

This report is accompanied by five geological maps as follows:: 1) Arch Creek (1::4760
scale; NTS 115 G/5 northeast); 2) Wellgreen area (1::4800 scale; NTS 115 G/5 northeast); 3) Linda Creek (1::2380 scale; NTS 115 G/6 northwest); 4) White River (1::4760 scale; NTS 115 F/15 northeast); and 5) Quill Creek (1::80 000; 115 G/5,6 north and 115 G/11,12 south).

Organization: Government of Yukon | Gouvernement du Yukon
Stratigraphy and regional implications of unstrained Devono-Mississippian volcanic rocks in the Money Creek thrust sheet, Yukon-Tanana Terrane, southeastern Yukon

Relatively unstrained Devonian-Mississippian volcanic and volcano-sedimentary rocks have been documented in the Money Creek thrust sheet in Finlayson Lake map area. The succession comprises a five-unit volcanic stratigraphy containing subaerial and subaqueous mafic and felsic volcanic and volcaniclastic rocks and associated sedimentary rocks that are underlain, and locally crosscut by, sub-volcanic mafic intrusions and quartz porphyritic granite. Magma-mingling relationships between mafic dykes and quartz-porphyritic granite suggest that mafic and felsic volcanism was broadly coeval. A published 360.5 ± 1 Ma U-Pb date on a quartz porphyritic granitic intrusion establishes the age of volcanism.

Biotite-hornblende granitic rocks of the Simpson Range Plutonic Suite (SRPS) intrude and metamorphose the volcanic sequence and related sub-volcanic intrusive rocks, and coupled with previously published U-Pb dates (345-350 Ma), this relationship implies that the SRPS is a distinctly younger pulse of magmatism.

Mafic and ultramafic rocks of the Money Creek thrust sheet have previously been correlated with the Pennsylvanian-Permian Campbell Range belt and together both have been considered part of the Anvil Allochthon or Slide Mountain Terrane. Field characteristics, age, and geochemistry show that neither correlation is valid.

Organization: Government of Yukon | Gouvernement du Yukon
U-Pb isotopic age dating by LAM ICP-MS, INCO Innovation Centre, Memorial University: Sample preparation methodology and analytical techniques

This contribution reports on sample preparation methods and Laser Ablation Microprobe Inductively Coupled Plasma Mass Spectrometry (LAM ICP-MS) analytical techniques routinely used to acquire U-Pb isotopic age data at the INCO Innovation Centre, Memorial University. Four concordant zircon reference materials that span from Miocene to Archean in age (9.52 Ma, 337.15 Ma, 1066.3 Ma and 2674.3 Ma) were recently analysed during a data collection session in which U-Pb isotopic data for 11 suspected Cretaceous plutonic rocks were being acquired. Final U-Pb age calculations determined for the four zircon reference materials are in excellent agreement with the corresponding known and/or published ID TIMS ages and demonstrate the reproducibility, accuracy and precision of the LAM ICP-MS technique. Furthermore, data collected for sample GP-09-02 demonstrate the applicability of the LAM ICP-MS technique for dating zircon populations as young as Miocene.

Organization: Government of Yukon | Gouvernement du Yukon