AndreaBozzo/ceres-open-data-index huggingface dataset:
Yukon Quaternary Geology - Volume 1 - 1996

These Quaternary research papers summarize the recent work of Quaternary scientists working in various areas of the Yukon. They are based on studies by government geologists, graduate theses and doctoral dissertations. This volume is the first in a series of publications which will document Quaternary research being done in Yukon in fields of surficial geology, placer geology, glacial history and geomorphology.

Organization: Government of Yukon | Gouvernement du Yukon
Updated geology of the Clark Lakes area in central Yukon (parts of 106D/2, 3, 6 and 7)

The Clark Lakes area is located along the northern boundary of the Selwyn fold belt, and is underlain by the Ediacaran to Cambrian Hyland Group. In the surrounding region, the Hyland Group and Paleozoic platformal carbonate rocks host several Au and polymetallic mineral deposits. The Clark Lakes area is bordered by regional-scale, southeast-striking thrust faults, which include the Dawson thrust to the northeast, and the Tombstone and Robert Service thrusts to the southwest. Based on stratigraphic relationships identified during 1:50000-scale bedrock mapping, Hyland Group rocks in the Clark Lakes area are considered to belong to the Cryogenian–Ediacaran Yusezyu Formation, the Ediacaran Algae Formation and the Ediacaran–Terreneuvian Narchilla Formation. The Yusezyu Formation has been subdivided into five units based on dominant siliciclastic lithofacies, which form a broadly coarsening-upward sequence. The Yusezyu and Narchilla formations host gabbro sills, and quartz monzonite occurs locally in the upper Yusezyu Formation. Rocks in the Clark Lakes area exhibit a steeply northeast-to-southwest-dipping foliation that is axial planar to southeast-trending folds.

Organization: Government of Yukon | Gouvernement du Yukon
2006–07 Supplementary estimates no. 1

Supplementary estimates no. 1 for the Government of Yukon 2006–07 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. November 2006, Whitehorse, Yukon.

Organization: Government of Yukon | Gouvernement du Yukon
First vertical derivative of the magnetic field, McQuesten Aeromagnetic Survey, NTS 115I/15, Yukon

Map of the first vertical derivative of the magnetic field derived from data acquired during an aeromagnetic survey carried out by Goldak Airborne Surveys from November 19, 2008 to February 19, 2009. The data were recorded using a split-beam cesium vapour magnetometer mounted in the tail boom of a Piper Navajo aircraft.

Organization: Government of Yukon | Gouvernement du Yukon
Surficial geology of Wellesley Lake (115J/05)

The Wellesley Lake map area includes a broad glaciated basin northwest of the Nisling Range between the Donjek and White rivers. Wellesley Lake, a large lake in the center of the basin, collects runoff from surrounding terminal moraine and bedrock uplands, and drains into the Donjek River.

Organization: Government of Yukon | Gouvernement du Yukon
Enhancing Natural Succession on Yukon Mine Tailings Sites: A low-input Management Approach

The revegetation of northern tailings sites presents many challenges. By using plants, which are naturally adapted to both the tailings environment and northern climatic conditions, fewer amendments and intervention will be required. In 2003, vegetation growing on and off the tailings and soil at three Yukon Territory, Canada, mine sites (United Keno Hill, Mount Skukum, and Wellgreen) was assessed and soil samples were collected. Through Canonical Correspondence Analysis (CCA), a statistical program that assesses relationships between plant species and environmental variables, I found that these plant communities are largely governed by a chemical-nutrient gradient (heavy metals and nutrients) and a ground cover gradient (bare and exposed conditions compared with full ground cover). The native grass Deschampsia caespitosa L. Beauv. was found colonizing all three tailings sites and its presence was associated with low nutrients, high heavy metal levels, and exposed ground, but it was also a habitat generalist. Five Yukon populations of D. caespitosa, originating from mine and uncontaminated sites were tested hydroponically for their tolerance to elevated Ni, Zn, and Cd concentrations. Intrinsic multiple metal tolerance occurred in all populations. In revegetation field trials in the Yukon, I planted seeds and transplants of 7 populations of D. caespitosa under different treatments: i) untreated, ii) compost, iii) fertilizer, and iv) combined (compost and fertilizer). At all sites, during the two years of data collection, local and non-local populations, including those from non-contaminated sites were able to establish, grow, and reproduce, even in unamended tailings and despite successive hot and dry summers. D. caespitosa also acted as a nurse crop, facilitating invasion of plants from adjacent habitats. The short term results suggest that the inclusion of Deschampsia caespitosa as a nurse crop for the revegetation of these northern mine tailings sites will be beneficial.

Organization: Government of Yukon | Gouvernement du Yukon
Morphological and compositional analysis of placer gold in the South Nahanni River drainage, Northwest Territories

Placer gold has been reported in small amounts throughout the South Nahanni river drainage; however, the original source of the gold is uncertain. This study focuses on two types of placer gold in the area: (1) locally abundant grains derived from near Selena Creek, and (2) scattered grains recovered from streams throughout the South Nahanni drainage area. A shape analysis of all gold grains was completed and representative grains from each sample population were selected for imaging on the scanning electron microscope, along with analysis for Au-Ag-Cu-Hg values on the electron microprobe. The gold grains are typically >700 fineness and mercury is below detection levels (<0.20%). Approximately half the grains analysed from the Selena Creek area registered near to, or slightly greater than, detection levels of copper (<0.04%), whereas the majority of grains from the isolated showings had copper contents below detection levels. The results are compared with published morphological and compositional data for placer and lode gold in other regions.

Organization: Government of Yukon | Gouvernement du Yukon
An evaluation of coal-bearing strata at Division Mountain (115 H/8 east-half, 105 E/5 west-half), south-central Yukon

The Division Mountain area is underlain primarily by Jurassic to Cretaceous(?) sedimentary rocks of the Laberge Group and Tantalus Formation. The Laberge Group is divisible into the following informal units: the Richthofen, Nordenskiöld, Conglomerate, and Tanglefoot formations. The Tanglefoot, which comprises a large portion of the exposed strata at Division Mountain, is here subdivided into the lower and upper members. The lower member consists of quartz-rich sandstone, grit, polymicitic conglomerate and laminated siltstone. The upper member is coal-bearing and typified by white grit, sandstone, and carbonaceous shale. The overlying Tantalus Formation is characterized by thick packages of resistant chert pebble conglomerate with intercalated sandstone beds, which form local highlands at Cub, Corduroy, Division, and Vowel mountains.

The strata at Division Mountain are folded into several upright, tight northwest-trending anticlines and synclines with
amplitudes of 2 to 7 km. The folded strata are intruded by feldspar-hornblende andesite sills and dykes.

Organic matter identified within coal and siltstone of the Tanglefoot and Tantalus formations consists of Type III and
subordinate Type I kerogen, suggesting the material is largely gas-prone. A combination of thermal maturation indicators (vitrinite reflectance and Tmax ) suggests that the coal and related strata are in the early to late stages of thermal diagenesis. Samples of the underlying Richthofen formation contain Type III kerogen matured beyond the oil window. Local folding and thickening of the Tanglefoot and Tantalus strata, as well as local intrusions in the Tanglefoot, may play a key role in the determination of hydrocarbon potential of the Division Mountain area.

Organization: Government of Yukon | Gouvernement du Yukon
Sedimentology and stratigraphy of placer gold deposits at Haggart Creek, central Yukon Territory

The Haggart Creek study area contains unconsolidated sediments, which represent six main geomorphic settings: 1) Reid-age glacial and glaciofluvial deposits; 2) McConnell-age proximal braided stream deposits to periglacial alluvial fans; 3) McConnell-age medial to distal braided stream deposits; 4) post-McConnell wandering gravel bed river; 5) Holocene gulch deposits; and 6) Holocene colluvium. Placer gold within the study area is known to originate from at least two main local lode sources: 1) gold in sheeted quartz veins within a Late Cretaceous-age granodiorite stock; and 2) gold in isolated quartz-sulphide fissure veins found in bedrock along Haggart Creek. Placer gold is believed to have formed as a result of reworking and re-concentration of gold during interglacial times, as well as reworking of older auriferous interglacial gravel by McConnell-age periglacial alluvium. The primary setting for placer gold deposits is Late McConnell to Early Holocene alluvium, on or near bedrock. Sub-crystalline to crystalline placer gold grains recovered from sediments found far removed from currently known local bedrock sources suggests that other lode sources may be present within the study area.

A copy of this thesis is available at the EMR library – QE195.W47 1999.
This thesis is available online at http://hdl.handle.net/1880/25379.

Organization: Government of Yukon | Gouvernement du Yukon
Geochemical Data from a National Geochemical Reconnaissance Stream Sediment and Water Survey in the Area of the Coal River, Southeast Yukon Territory (Part of NTS 95E)

A stream sediment and water survey was carried out in the Coal River area of southeastern Yukon during the summer of 2005. This survey was carried out under a Joint Research Agreement between the Yukon Government (Oil & Gas and Mineral Resources Division of the Department of Energy, Mines and Resources) and the Federal Government, acting through the Earth Science Sector's Metals in the Environment Program.

Analytical data accompany this document for 50 elements in stream sediments and 60 variables in waters from a total of 174 sites sampled in 2005. National Geochemical Reconnaissance protocol was used for the collection, preparation and analysis of waters and silts. Samples were collected in the Yukon Territory portion of NTS map sheet 95E, west of the height of land that marks the boundary between Yukon and Northwest Territories and separates the Coal River and Flat River drainage basins.

Organization: Government of Yukon | Gouvernement du Yukon
Geologically-constrained inversion of magnetic and gravity data over parts of the Yukon-Tanana terrane and Whitehorse trough

In the winter of 2013 the Yukon Geological Survey (YGS) contracted Mira Geoscience to undertake a 3D geologically constrained modelling exercise to take advantage of a wealth of new geological and geophysical data. These data include new gravity and aeromagnetic surveys, new bedrock geology maps, rock property data and a seismic survey. The area of interest covers much of the northern Whitehorse trough south and east of Carmacks and extends west to Aishihik and Sekulmun Lakes. The goals of this project were to develop a better understanding of the geological relationships in an area of poor bedrock exposure, extending this knowledge to the subsurface and ultimately to provide insight into targeting for mineral and oil and gas exploration.

This project was funded under the SINED (Strategic Investments for Northern Economic Development) program. The new aeromagnetic surveys used in the development of the inversion models were products of the GEM (GeoMapping for Energy and Minerals) program of Natural Resources Canada. Detailed gravity surveys were funded through SINED and new bedrock mapping through YGS’s internal operating budget.

Organization: Government of Yukon | Gouvernement du Yukon
Field-portable x-ray fluorescence spectrometer use in volcanogenic massive sulphide exploration with examples from the Touleary occurrence (MINFILE Occurrence 115O 176) in west-central Yukon

Field-portable x-ray fluorescence analysers (pXRF) are becoming a common tool in the savvy mineral explorer’s tool kit. Benefits include portability and ease of use, real-time acquisition of XRF data with minimal processing, immediate availability and analysis of data in the field, and a reasonably large number of elements that can be measured reliably. The findings indicate that data for 15 elements obtained with an Innov-X Omega pXRF analyser (2010 version) correlate well with lithogeochemical whole-rock analyses with R² values generally =0.7. The difference in elemental abundances between pXRF analyses of thin section off-cuts (a proxy for drill core) and pulps from the whole-rock analyses are generally ± 35%, indicating that no sample preparation is needed for the rock samples analysed in this study. The uncorrected pXRF values of some elements can be very similar to whole-rock analytical abundances; however, it is recommended that uncorrected pXRF data only be used semi-quantitatively, such as for downhole elemental plots in which relative patterns or trends are more informative than individual data points. For more sophisticated plots such as those combining elements into ratios to form alteration indices, corrected pXRF data should be used. The pXRF data are also adequate for construction of simple volcanic composition plots that can be used to aid in identification of protolith compositions of altered samples. The pXRF is well suited to volcanogenic massive sulphide exploration as the analytical data obtained from drill core (using thin section off-cuts as a proxy) are comparable to whole-rock analyses and the range of immobile and mobile, major and trace elements should be versatile enough for most exploration programs. However, pXRF shouldn’t be viewed as a replacement to traditional whole-rock geochemical methods.

Organization: Government of Yukon | Gouvernement du Yukon
An Evaluation of the Gold Recovery of Placer Drills Using Radio Tracers (Part II)

In the last five years, eroding gold prices, increasing production costs and the depletion of reserves have resulted in a dramatic increase in the use of drilling to evaluate placer deposits. Accurate sampling and deposit evaluation would enable planning for cost-effective mining and reclamation. However, sampling placer gravel accurately is an extremely difficult task due to the nugget effect (inclusion or loss of a single particle of gold) and any errors are compounded by the small size of the drill samples. Additional sampling errors result from contamination, splitting and fire assaying. More placer mine failures can be attributed directly to improper sampling and sample processing practices during property evaluation than to any other cause.

There is very little impartial, accurate information available to guide the selection of modern drills. Drillers and their equipment are often selected for their penetration rate or cost-per-foot rather than for sampling accuracy or gold recovery. A brief description of several types of drills including churn, auger, rotary tricone, reverse circulation, Becker hammer, down-the-hole hammer and Sonic drills is summarized in Section 6 from references.

Three solid auger drills, two types of fully cased normal circulation (N/C) drills and two types of reverse circulation (R/C) drills were evaluated under typical Yukon field conditions using radioactive placer gold as tracers (radiotracers). A frozen cylindrical core of compacted gravel containing four sizes (1.2-1.7, 0.60-0.84, 0.3-0.42 and 0.15-0.21 mm) (-10+14, -20+28, -35+48 and -65+100 mesh) of radiotracers was placed in 44 drill holes and the holes were redrilled. Hand-held scintillometres were used to track gold losses during drilling, sample recovery and sample processing. Radiotracers lost due to spillage and blow-by around the collar (top) of the hole, and those trapped in drilling equipment (carry-over) were easily located. The results of these tests are summarized Table 1.

There was no significant difference between the recovery of the four sizes of gold particles with any of the fully cased nomal circulation, reverse circulation or auger drills tested. Observations and down-hole scintillometre records indicate that the radiotracers did not follow the bit down the hole and were either carried out of the hole or forced onto to the sides of the hole at or above the depth at which the radiotracer core was positioned.

Organization: Government of Yukon | Gouvernement du Yukon
Landsliding at Cement Creek, Kluane Ranges, Southwestern Yukon

A large block slide affecting an area of approximately 1.0 square km was reported to have occurred on Cement Creek Y.T. (115G/5) between February 15 and March 15, 1983. Landsliding is confined to basaltic andesites in the lower unit of the Wrangell Lavas. Hydrothermal alteration of flow-top breccias and the tilting of strata towards an open face bordering Cement Creek predispose rock to slip along bedding planes. Surveys conducted during June to August 1986 detected displacements of 10-12 cm during an 8 week period. Seismic refraction and electrical resistivity surveys conducted on the slide mass suggest that most ground failure was caused by strong ground motion during an initial episode of rapid displacement and that the rupture surface lies beneath the lower limit of permafrost. Ground-water accumulation on and above the rupture surface followed by landslide initiation during a burst of low magnitude seismicity is suggested as a slide mechanism.

Organization: Government of Yukon | Gouvernement du Yukon
Micropetrology and mineral geochemistry of the Tombstone and Deadman plutons, Tombstone Plutonic Suite, central Yukon.

Micropetrographic observations and mineral geochemistry data, along with previously reported whole-rock geochemistry, defined an A-type granite-affinity for the Tombstone and Deadman plutons of the 120-km-long, mid-Cretaceous Tombstone-Tungsten plutonic belt. This plutonic belt was intruded into the western Selwyn basin, the western-most edge of the ancestral North American craton, and is situated well inboard of any potential subduction-zone plutonism, which is found in the accreted terranes that were juxtaposed with the North American craton during the Jura-Cretaceous.
More than a dozen mineral specimens were petrographically observed and five were chemically analysed. Similarities found among the two plutons are their alkalic nature, minimal quartz content, presence of igneous andradite garnets and the presence of rare-earth-bearing minerals. Differences between the two plutons include the fact that the Tombstone pluton contains Th, Ce and La with magnetite and titanite, while the Deadman pluton contains Nd with Ce and La, as well as Ba-rich alkali feldspars. These observations are not commonly found in tectonic-related I- or S-type granitoids, and distinguish the Tombstone plutonic suite as being most similar to A-type granites.

Organization: Government of Yukon | Gouvernement du Yukon
2019–20 Supplementary information and statistics

Supplementary information and statistics for Executive Council Office.
This document was prepared by Executive Council Office for the Department of Finance and published with the 2019–20 Budget. These documents were prepared by the Government of Yukon for the 2nd Session of the 34th Legislature, Yukon Legislative Assembly. March 2019, Whitehorse, Yukon.

Organization: Government of Yukon | Gouvernement du Yukon
2010–11 Supplementary estimates no. 1

Supplementary estimates no. 1 for the Government of Yukon 2010–11 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. September 2010, Whitehorse, Yukon.

Organization: Government of Yukon | Gouvernement du Yukon
Surficial geology, Ross River Region, Yukon, parts of NTS 105K/1 & 2 and 105F/15 & 16

Local-scale surficial geology mapping was completed as part of a community hazards mapping program coordinated by the Northern Climate ExChange (Yukon Research Centre, Yukon College). This program assesses potential landscape hazards under changing future conditions by incorporating a variety of data sets, including surficial geology, topography (slope and aspect), permafrost distribution, site-specific permafrost data (e.g. ground penetrating radar, electrical resistivity tomography and borehole data), analyses of past hydrological and climatological trends, and future climate projections. The surficial geology map describes surface landscape features, sediment texture, genetic material, surface expression and geomorphological processes. Detailed descriptions of local surficial geology and hazard analysis methodology are presented in the accompanying report. The accompanying landscape hazard classification map identifies existing and potential geological hazards such as landslides, permafrost stability and flooding; the hazard map is presented in stoplight colours to provide an intuitive tool for community decision makers aiming to incorporate an adaptation planning framework into existing land use management practices.

Organization: Government of Yukon | Gouvernement du Yukon
Wernecke Breccias and Fe, Cu, U Mineralization: Quartet Mountain-Igor area (NTS 106E)

The "Wernecke Breccias" are enigmatic, but significant features of the Middle Proterozoic Wernecke Supergroup in the Wernecke and Ogilvie Mountains. This report describes the breccias near Quartet Mountain and the Igor prospect in the Wernecke Mountains. Widespread, pervasive metasomatism and greenschist facies metamorphism of both the breccias and wall rocks is demonstrated by the development of chlorite, calcite, dolomite, siderite, albite, hematite, sericite, biotite and quartz. Altered fragments are multicoloured and give the appearance that they are transported, and exotic, but all are locally derived. Structures in relatively unaltered breccias suggest that brecciation was accompanied by mylonitization and faulting. Repeated brecciation, metasomatism, and faulting characterize development of the breccias. Small gabbro and diabase dykes and sills are associated with the breccias. The breccias contain numersouss, small occurrences of copper, iron, barium, molybdenum, uranium, cobalt, gold, and silver. Crustal extension and detachment faulting, and large buried intrusions beneath the breccias are suggested as possible genetic mechanisms.

Organization: Government of Yukon | Gouvernement du Yukon
Yukon placer mining 2021 development and exploration overview

Yukon’s placer mining industry continues to display its resilience through another mining season during a worldwide pandemic. The pandemic continues to bring delays and challenges that affect many facets of the industry, ranging from interruptions in the supply chain to isolation requirements for workers. Despite these challenges, production value remained high, and new production was noted from a number of creeks that have not produced in the recent past. With an expanding number of placer creeks producing and stable production from the traditional mining areas, the industry continues to display its economic significance for the territory.

Organization: Government of Yukon | Gouvernement du Yukon