AndreaBozzo/ceres-open-data-index huggingface dataset:
Late Cambrian and Ordovician Alkalic Magmatism Along the Dawson Fault, Yukon: Evidence for Multiple Reactivations of a Rift‐Transfer Fault in the Northern Canadian Cordillera

Lower Paleozoic continental margin rocks of the North American Cordillera, from Yukon to Nevada, include coeval platformal carbonate and basinal clastic strata that are offset along rift‐transfer faults, including the Liard, St. Mary‐Moyie, and Snake River structures. The Dawson fault is a prominent east‐weststriking structure in central Yukon that is interpreted herein to have been active as a rift‐transfer fault by late Cambrian time. This hypothesis is supported by new zircon U‐Pb dates that range from 501.98 ± 0.17 Ma to 497.57 ± 0.70 Ma from alkaline mafic volcanic rocks concentrated along the Dawson fault. The development of a sub‐Jiangshanian unconformity immediately post‐dates this alkaline magmatism and indicates that final continental breakup and establishment of the northern Cordilleran margin occurred by the late Miaolinginan. Alkaline magmatism caused by local decompression partial melting of the mantle may have been triggered by the release of in‐plane tensile stresses during lithospheric rupture and edge‐driven mantle convection. Upper Ordovician alkaline mafic volcanic and plutonic rocks that occur along a northwest‐southeast striking segment of the Dawson fault erupted ∼50 Myr after breakup and represent an example of post‐rift magmatism along a rift‐transfer fault. New bedrock mapping, and geochronological, paleontological, and petrological results from Upper Ordovician rocks indicate that there was localized basin development and punctuated volcanism along the Dawson fault from 453 to 447 Ma. Late Ordovician extension and post‐breakup magmatism in central Yukon is compatible with dextral strike‐slip reactivation of the Dawson rift‐transfer fault associated with counterclockwise rotation of Laurentia.

Organization: Government of Yukon | Gouvernement du Yukon
Regional lake sediment geochemical data, Watson Lake area, southeastern Yukon (NTS 105A)

This data package contains results for parts of the Watson Lake area (NTS 105A). This information has been provided in a variety of digital formats. PDF files include survey descriptions and details regarding methods, analytical data listings and summary statistics. Raw digital data of original field and analytical information plus new reanalysis results are included in Microsoft®Excel (XLS) format.

Organization: Government of Yukon | Gouvernement du Yukon
Geochronologic and Pb-isotopic constraints on gold mineralization at the Plateau South property (Yukon MINFILE 105N 034, 035, 036), central Yukon

Quantitative mineralogy, U-Pb geochronology of zircon and monazite, 40Ar/39Ar geochronology of muscovite and sericite, and Pb isotopes from galena in veins and feldspar in plutons provide insight into the age of metamorphism, mineralization, intrusion emplacement and the sources of metals at the Plateau South (MINFILE 105N 034, 035, 036) occurrences in central Yukon. Orogenic mineralization and metamorphism is ca. 110 Ma to 100 Ma, and possibly as old as ca. 130 Ma. Following deformation and regional metamorphism, two biotite-muscovite plutons, the Russell stock and Armstrong pluton, were emplaced at 95.39 ± 0.03 Ma and 95.51 ± 0.03 Ma, respectively. These plutons are here reassigned to the Tungsten suite based on mineralogy, chemistry and age. Coeval with these plutons are contact metamorphism and possibly intrusion-related mineralization. Lead isotopic data from galena cluster into two groups: Group 1 is enriched in thorogenic Pb with 206Pb/204Pb values between 18.31 and 18.14, 207Pb/204Pb between 15.62 and 15.55 and 208Pb/204Pb between 38.77 and 38.30. Group 2 is isotopically evolved with 206Pb/204Pb values between 19.13 nd 18.91, 207Pb/204Pb between 15.78 and 15.63 and 208Pb/204Pb between 39.24 and 39.07. We suggest that late Early Cretaceous mineralization is related to large-scale orogenic fluids that tapped primitive (deep?) metal sources and early Late Cretaceous mineralization, coeval with local intrusions, sourced isotopically distinct metals from the intrusions. Alternatively, all mineralization could relate to Early Cretaceous orogenic fluids but with heterogeneous, locally derived metal sources and thermal resetting of Ar ages near the intrusions.

Organization: Government of Yukon | Gouvernement du Yukon
A review of serveral Yukon revegetation projects and techniques

Revegetation projects in Yukon typically involve reclamation and erosion control of disturbed areas from mining and road construction related activities. The general purpose of the revegetation is to restore or stabilize these disturbed areas. However, because of Yukon’s harsh climate, lack of precipitation, and higher latitude, the success rate of various revegetation efforts is variable. Revegetation techniques used with success in more southern locations are not guaranteed to work here and little is available in terms of comparative evaluations of their use in Yukon. This report provides a summary and an evaluation of various revegetation and erosion control projects completed mostly in the past 15 years. It describes their successes and failures in an attempt to provide a guide for future restoration work and to help improve success (Section 3). Section 4 of the report provides an overall review summary to capture the essence of the various techniques. We end the report with a short list of recommendations for future work in Section 5 and acknowledgements in Section 6. Summaries of monitoring information from each site reviewed are presented in Appendix A.

Organization: Government of Yukon | Gouvernement du Yukon
Surficial geology of Burwash Landing and Destruction Bay (parts of NTS 115G/2, 6 and 7), Yukon

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
Using terrestrial cosmogenic nuclides to constrain timing of penultimate ice advance in the Ogilvie Mountains, Yukon

Throughout the Pleistocene epoch, Yukon was repeatedly influenced by glacial ice originating from the Cordilleran Ice Sheet and independent alpine glaciers. The penultimate limit in Yukon has garnered controversy in recent years, as moraines in the central region of the territory were found to be older (MIS 6) than moraines in the southwest part of the territory and Alaska (MIS 4). The Ogilvie Mountains, located east of Dawson City, have proven especially problematic for chronological studies. This study will attempt to test a relatively new dating method on penultimate surfaces in the Ogilvie Mountains; Chapman Lake is the primary study area. Using a vertical sampling method to construct a cosmogenic depth versus concentration profile in outwash gravel, this research will determine whether Marine Isotope Stage 4 or 6 provided the conditions necessary for ice nucleation to build the penultimate glacial surface. The age calculated by the depth profile is supported by radiocarbon ages and macrofossil samples, optically stimulated luminescence ages, TCN boulder dating, as well as detailed stratigraphy of significant sites near the Chapman Lake moraine. The results will help determine the effects of climate forcing in this region and its relationship to the existing glacial framework of the territory.

Organization: Government of Yukon | Gouvernement du Yukon
Mt. Hundere deposit, southeastern Yukon

In 1990, Curragh Resources announced its intention to spend $70 million to develop a high-grade zinc-lead-silver mine at Mt. Hundere, 54 km north of Watson Lake. The deposit has formed by the replacement of limestone at the sheared contact between Lower Cambrian limestone and phyllite. Proved reserves are approximately 4 million tonnes in 4 zones, with an average grade of 8.45% Pb, 132.% Zn and 50 g/t Ag. The ore is coarse grained and free of impurities and the waste will be non-acid generating due to the limestone host rock and the relatively low amount of waste sulphides. Production is estimated at 100 000 to 150 000 tonnes of concentrate per year over a mine life of 8.5 years.

Organization: Government of Yukon | Gouvernement du Yukon
Preliminary detrital zircon geochronology of the Neruokpuk Formation in the Barn Mountains, Yukon

Neoproterozoic to Cambrian siliciclastic rocks in the Barn Mountains, Yukon are stratigraphically similar to coeval strata on the northwest Laurentian margin and the North Slope subterrane of the Arctic Alaska terrane. Sandstone samples collected for detrital zircon U/Pb geochronology from Oldhamia-bearing sections in the Barn Mountains yield age spectra with major Paleoproterozoic and subordinate Mesoproterozoic and Archean peaks that are compatible with a Laurentian cratonal provenance. Comparison of data from the Barn Mountains with available data from the Laurentian margin is permissive of derivation from either the northwestern or the north to northeastern margin of Laurentia.

Organization: Government of Yukon | Gouvernement du Yukon
White Channel Gravel alteration revisited

The White Channel Gravel (Pliocene) is the most important gold-bearing unit in the world famous Klondike goldfields of west-central Yukon. It is up to 46 m thick and consists of framework-supported, poorly bedded, slightly muddy sandy gravel that was deposited by braided rivers. Historically, this unit is subdivided into a lower 'white gravel' and an upper 'yellow gravel'. The colour of the white gravel is due to an abundance of quartz clasts and an alteration of the sand-mud matrix that has been referred to as 'leaching' or 'bleaching'. Previous researchers concluded that the alteration is hydrothermal in origin, but a review of this research shows that there is no unequivocal evidence supporting hydrothermal alteration. Petrographic examination of in situ samples from both the white and yellow gravel reveals a depositional fabric and an alteration fabric, although the alteration is better developed in the white gravel. The alteration is reinterpreted as the result of weathering, and particularly diagenesis due to groundwater flow.

Organization: Government of Yukon | Gouvernement du Yukon
Ancient Pacific Margin: A preliminary comparison of potential VMS-hosting successions of the Yukon-Tanana Terrane, from Finlayson Lake district to northern British Columbia

In the inaugural year of the joint Geological Survey of Canada - British Columbia Geological Survey Branch - Yukon Geology Program Ancient Pacific Margin NATMAP project, substantial progress was made in documenting the nature of Yukon-Tanana Terrane in Yukon and northern British Columbia and how the different parts may have been linked paleogeographically. When ca. 425 km of displacement on the Tintina Fault are restored, the Finlayson Lake massive sulphide district lies north of and along strike from the Glenlyon and Wolf Lake - Jennings River study areas.

Stratigraphic sections from the component study areas illustrate similarities and differences along strike; both the similarities and differences with the Finlayson Lake stratigraphy affirm the potential of this belt to host volcanogenic massive sulphide mineralization.

Organization: Government of Yukon | Gouvernement du Yukon
2009–10 Supplementary estimates no. 1

Supplementary estimates no. 1 for the Government of Yukon 2009–10 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. October 2009, Whitehorse, Yukon.

Organization: Government of Yukon | Gouvernement du Yukon
The Stewart River placer project, west-central Yukon

The Stewart River map area (115 O&N) is the most important historic and current placer gold producing region in the Yukon. Unfortunately, the historic placer-gold deposits are becoming depleted, and more efficient mining of existing deposits and exploration for new deposits must be encouraged. Although placer deposits in the Klondike district are well described and their origin is quite well understood, placer deposits in the remaining part of the Stewart River map area have not been so well documented. The purpose of the Stewart River placer project is to describe and document the geology of known placer deposits, to interpret the formation of the placer deposits, and to relate the geology of the placer deposits to the regional surficial and bedrock geology. The objectives of the project are to aid in the exploration and mining of placer deposits by providing a comprehensive and up-to-date placer geoscience database. The utility of the placer database is that it can be used to construct placer deposit models (general summaries of given placer settings). These models then serve as predictors for future placer exploration and mining. Fieldwork for the project began in 1998 and will be completed in 2001; results of the project will be published in a final report and a resource appraisal map for placer gold.

Organization: Government of Yukon | Gouvernement du Yukon
Geology and metamorphic conditions in rocks of the Cassiar Terrane, Glenlyon map area (105L/1), south-central Yukon

Lower Paleozoic miogeoclinal calcareous rocks of the Cassiar Terrane are intruded by the Early Cretaceous Glenlyon Batholith. Garnet-biotite and garnet-muscovite-biotite-aluminum silicatequartz geothermobarometry on the intrusive wall rocks indicate metamorphism to lower amphibolite facies at temperatures of approximately 700°C and pressures of approximately 3 kbar. Progressive deformation, indicated by porphyroblast-matrix relationships, are interpreted to be a result of minor displacements of the country rock associated with and facilitated by intrusion of the Glenlyon Batholith, followed by static heating. Isolated skarn units exist along contacts between the batholith and its wall rocks. A skarn unit is also present along a nearby north-northeast-trending dextral strike-slip fault that predates and is intruded by the batholith.

Organization: Government of Yukon | Gouvernement du Yukon
Alteration and zonation in the Kalzas W-Sn-Mo Porphyry-vein deposit, 105 M/7, Yukon

The Kalzas W-Sn-Mo deposit is located in central Yukon, 282 km north of Whitehorse on the northern side of Big Kalzas Lake. Wolframite-molybdenite-cassiterite mineralization occurs in sets of large planar quartz veins which cross-cut Selwyn Basin clastic rocks of the Upper proterozoic Windermere Supergroup, or "Grit" unit. The deposit has a concentric alteration halo with an outer sericite dominated zone, an inner "potassic' core and intense tourmalinization throughout the potassic zone and part of the sericite fringe. Intense fracture and quartz-tourmaline veinlet stockwords are present. No plutonic rocks are exposed in the local area though an underlying pluton is suspected.

Kalzas has similarities to many wolframite deposits throughout the world, including those of southeast Asia which contain the bulk of world tungsten reserves. In contrast, North American tungsten mines having wolframite as the dominant tungsten phase are not as common as scheelite skarn deposits which produce most of our domestic tungsten.

Organization: Government of Yukon | Gouvernement du Yukon
Use of Diffuser Systems for Dispersion of Placer Mining Effluent

Placer mining involves washing stream gravel to separate and save free gold particles. Usually a placer mine must discharge excess effluent water, which contains some residual suspended fine silt and clay particles, from a settling pond, back into the stream. This study examines the applicability of introducing placer effluent through a diffuser to lessen environmental impact.

A diffuser is a mechanism which introduces effluent fluid into the main current of a receiving stream so that mixing and dispersion are facilitated. A diffuser usually consists of a header pipe with one or more discharge ports. Effluent is ejected from the ports at high velocity into the receiving water. Performance of the diffuser depends on the diameter, spacing, and angle of the ports in relation to the water column.

Diffusers are used effectively in many industrial applications. Computer programs have been developed which predict the effluent plume from a diffuser, using input data from both the receiving stream and the effluent discharge. We used the CORMIX model, which was developed for the U.S. Environmental Protection Agency. This program can also be used in the design of diffusers.

We modelled two series of scenarios using receiving water data for the Fortymile River. In one series, we varied the concentration of suspended solids in the effluent. In the other series, we varied the flow rate of the effluent. In alll cases from both of these series of models, the CORMIX program predicted that the effluent diffused into the receiving water rapidly. A water quality objective of 12.5 mg of suspended sediment per litre of water was achieved in a very short distance downstream of the diffuser.

We also used the CORMIX model to predict effluent behaviour in some hypothetical receiving streams. These scenarios showed that the larger the receiving stream, the better the diffusion rate. It also showed that diffusers would not be as effective on small streams where large effluent concentrations are discharged. Dilution is limited by the flow rate of the receiving water.

The CORMIX model cannot predict whether sediment from the effluent plume will settle out on the streambed. Our team hydrologist examined the question of potential sedimentation by using the following techniques:: comparing background to introduced sediment levels, calculating the shear/fall velocity ratio for the sediment, comparison to flume testing, and comparison to other field investigations. He predicted that in the example of the Fortymile River using our mine effluent parameters, there would be little or no sediment deposited on the streambed from a diffuser installation.

The use of diffuser systems to disperse placer effluent into receiving water appears to be an effective way of mitigating the impact of placer mining on the aquatic environment, providing there is adequate flow in the receiving stream. Effluent is dispersed into the stream flow, reducing the possibility of sedimentation of the stream substrate.

Organization: Government of Yukon | Gouvernement du Yukon
Lithostratigraphic metallotect ranking of non-plutonic rocks in Yukon

The purpose of the project is to use the lithostratigraphic data in the Yukon bedrock geology geodatabase to rank geologic polygons in terms of their capability to host mineral deposits. Twelve specific mineral deposit models are considered; lithostratigraphic metallotect maps have been created for each deposit type. These maps and the associated table of metallotect rankings are envisioned as layers of information for mineral potential studies and mineral exploration.

Organization: Government of Yukon | Gouvernement du Yukon
Carmacks surficial geology and community hazard susceptibility mapping

The Carmacks surficial geology and community hazard susceptibility mapping was completed to support land use planning, but also provides a valuable base map for public education about the origins of the landscape. The Village of Carmacks spans the Yukon River valley at the mouth of the Nordenskiöld River and the landscape reflects the areas recent glacial and post-glacial history. About 16¿000 years ago, a large glacier melted in the vicinity leaving behind a complex topography of undulating hills and depressions. This was subsequently eroded through by the Yukon River, and large gravel terraces formed, providing a foundation for the community. Natural changes to the landscape continue and these changes can present public safety hazards and risks to current and future development projects. This map and associated hazard assessment provides the necessary baseline information to make informed land use decisions through identifying which areas of the community are most susceptible to landscape hazards. The most common hazards present in the community include, river erosion and flooding, landslides, and permafrost. It is our goal to provide Yukon communities with accurate geological knowledge concerning these natural processes, with the hope they are referenced in all future planning. Palmer Environmental Consulting has completed the most detailed surficial geology mapping and thorough analyses of potential landscape hazards ever produced for the greater Carmacks area.

Organization: Government of Yukon | Gouvernement du Yukon
2014–15 Supplementary estimates no. 3

Supplementary estimates no. 3 for the Government of Yukon 2014–15 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 2015, Whitehorse, Yukon.

Organization: Government of Yukon | Gouvernement du Yukon