Geoscience Canada最新文献

{"title":"Canadian Geoscience Diplomacy in Collaboration with IUGS, UNESCO IGCP Geoparks, and World Heritage Geosites: Past, Present, and Future","authors":"Nikole Bingham-Koslowski, Katherine J.E. Boggs, Özlem Adiyaman Lopes, Daniel Lebel, Stephen Johnston, Guy Narbonne","doi":"10.12789/geocanj.2023.50.204","DOIUrl":"https://doi.org/10.12789/geocanj.2023.50.204","url":null,"abstract":"To commemorate the 60th anniversary of IUGS and the 50th anniversary of IGCP, the 2022 symposium entitled “IUGS, Geoparks, and IGCP – Retrospection, today and the future” was coordinated at the GAC-MAC-IAH-CNC-CSPG 2022 Conference in Halifax (16–18 May) with the companion Cliffs of Fundy UNESCO Geopark field trip (19–21 May). Canadian leadership within IUGS and IGCP includes J.M. Harrison as the first president of IUGS in 1961, Antony Berger’s work publishing “Episodes”, which is the IUGS’ quarterly international scientific journal, and Canadian leadership on multiple IGCP projects summarized here. Two panel discussions examined the future of geosciences, UNESCO Geoparks and World Geoheritage Sites in Canada. The need for improved communications with politicians, policymakers, and the general public through education and outreach was emphasized in these panel discussions. UNESCO Geoparks (such as the Cliffs of Fundy), UNESCO World Heritage Geosites and significant museum displays represent vehicles for improving communications with the general public about geosciences and potentially inspiring future geoscientists. This report provides a summary of the symposium and explores some of the many themes that it addressed.","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":" 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Implications of Ontario’s Historical Oil and Gas Drilling and Abandonment Practices for Abandoning Orphan and Legacy Wells","authors":"Dru J. Heagle, Robert Sealey","doi":"10.12789/geocanj.2023.50.203","DOIUrl":"https://doi.org/10.12789/geocanj.2023.50.203","url":null,"abstract":"Oil and gas exploration in Ontario began in the mid-1800s, leading to the first oil well drilled in 1858 and the first commercial gas well drilled in 1889. These early discoveries kicked off a boom of exploration and development drilling activity, but well records were not mandatory until 1919 after the introduction of the Natural Gas Act R.S.O.1918, c. 12. The Ontario Bureau of Mines estimated 10,000 operating oil wells in the province at the turn of the 20th century, but there are only records for approximately 1,500 wells. By 1970 there were an estimated 50,000 wells drilled in the province though there are only records for 27,000 wells, indicating there may be tens of thousands of unrecorded or lost wells in southwestern Ontario. Wells that are not properly plugged are a conduit for fluid movement, including brine, natural gas, oil, and hydrogen sulphide, to move from the subsurface to the surface. Historical well abandoning regulations required wells to be plugged with inferior materials including wood, clay, and rubble. Cement was not the standard plugging material until 1964. There are orphaned and legacy wells leaking natural gas and sulphur water (groundwater containing dissolved sulphate and hydrogen sulphide) creating a risk to public safety. Orphaned and legacy wells are also a risk for subsurface energy projects including geological storage of carbon dioxide, hydrogen, and compressed air energy, because the wells may provide a pathway for injected fluids to return to the surface. This study reviews well construction, legislation, and abandonment practices in Ontario beginning in 1858 and identifies five factors impacting the plugging and abandonment of orphaned and legacy wells.Further work is required to locate unreported or lost wells and to develop new techniques to permanently plug wells to limit gas leakage, reduce greenhouse gas emissions, and improve public and environmental safety.","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":" 42","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138964327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Logan Medallist 8. Trace Elements in Iron Formation as a Window into Biogeochemical Evolution Accompanying the Oxygenation of Earth’s Atmosphere","authors":"K. Konhauser, A. Kappler, Stefan V. Lalonde, L. Robbins","doi":"10.12789/geocanj.2023.50.201","DOIUrl":"https://doi.org/10.12789/geocanj.2023.50.201","url":null,"abstract":"Iron formations exemplify a type of sedimentary rock found in numerous Archean and Proterozoic supracrustal successions. They serve as a valuable chemical record of Precambrian seawater chemistry and post-depositional iron cycling. These formations accumulated on the seafloor for over two billion years during the early history of our planet, offering a unique opportunity to study environmental changes that occurred during Earth's evolution. Among these changes, one of the most significant events was the shift from an anoxic planet to one where oxygen (O2) became consistently present in both the marine water column and atmosphere. This progression towards global oxygenation was closely linked to the emergence of aerobic microbial metabolisms, which profoundly impacted continental weathering processes, nutrient supply to the oceans, and ultimately, the diversification of the biosphere and complex life forms. In this review, we synthesize two decades of research into the temporal fluctuations of trace element concentrations in iron formations. Our aim is to shed light on the complex mechanisms that contributed to the oxygenation of Earth's surface environments.","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":"206 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139175196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brandon 2024: GAC–MAC–PEG Joint Annual Meeting Field Trips","authors":"Chris Coueslan","doi":"10.12789/geocanj.2023.50.205","DOIUrl":"https://doi.org/10.12789/geocanj.2023.50.205","url":null,"abstract":"","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":"7 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139173929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trace Element Composition of Placer Gold Across the Okanagan Fault, Kelowna, British Columbia, Canada","authors":"John Greenough, Mikkel Tetland","doi":"10.12789/geocanj.2023.50.202","DOIUrl":"https://doi.org/10.12789/geocanj.2023.50.202","url":null,"abstract":"For 100 years, placer gold has been important to the settlement, economic development, and, recently, recreational geology of the Kelowna, British Columbia, area. It is best-known to occur in modern-day, Mission Creek and Lambly Creek sedimentary rocks, as well as a paleoplacer occurrence in Miocene sediments of the historical Winfield mine. The Mission Creek and Winfield localities are east of the west-dipping, low-angle, normal Okanagan Fault, which has been active since the Eocene. Lambly Creek is west of the fault. Late Paleozoic to Eocene igneous and metasedimentary rocks occur in the Lambly Creek catchment but Eocene gneiss units, unroofed by the fault, occur on the Okanagan Valley’s east side. This study tests the hypothesis that native placer gold compositions vary across the Okanagan Fault reflecting different sources and histories for the gold. A modest number of Au and Ag analyses (23 analyses) in usefully representative placer gold samples were determined on a scanning electron microscope with an energy dispersive spectrometer (SEM-EDS). Spots analyzed for Au and Ag were also analyzed for 19 trace elements using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Mercury was semi-quantitatively determined in ‘unknown’ gold grains by first estimating its concentration (~3.69 ppm) in the AuRM2 external standard. Proportions of Au:Ag:Cu in grain cores indicate all the gold came from mesothermal/hypogene or possibly Au porphyry bedrock deposits though primary signatures may have been obscured by metamorphism or weathering. Winfield and Mission Creek grains tend to have higher siderophile Fe, Ni, Pd and Pt and chalcophile elements As, Se, Te, Hg, Pb and Bi but lower Cu and Sb concentrations than Lambly Creek gold. Mercury is distinctly higher in Winfield and Mission Creek gold than in Lambly Creek gold from the west side of the valley; the element appears particularly useful for ‘fingerprinting’ gold. Lambly Creek gold compositions indicate derivation from two orogenic/hypogene sources from greenstone and plutonic/hydrothermal rocks present in the catchment area. Modern day Mission Creek and Miocene paleoplacer Winfield grains have a similar hypogene trace element signature but there are no known local bedrock gold sources. The Mission Creek and Winfield gold grain cores are surrounded by < 10 µm, Au-rich, Ag- and trace element-poor, rims. Lambly Creek grains lack such rims. The Au-rich rims on modern day Mission Creek and Miocene Winfield gold may reflect prolonged near-surface exposure with surficial electrochemical dissolution of hypogene trace elements or the biological precipitation of gold. Low Ag and red colouration on the surface of grains support the biological precipitation hypothesis. The shared trace element signature, together with the Au-rich rims indicate that modern day placer gold in Mission Creek was multiply reworked from Miocene paleoplacers similar to the Winfield occurrence as a result of uplift a","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":" 26","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GAC-MAC-SGA 2023 Sudbury Meeting: Abstracts, Volume 46","authors":"Michael Lesher","doi":"10.12789/geocanj.2023.50.200","DOIUrl":"https://doi.org/10.12789/geocanj.2023.50.200","url":null,"abstract":"","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135743769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Earth Science Education #7. GeoTrails: Accessible Online Tools for Outreach and Education","authors":"Katie M. Maloney, Alexander L. Peace, Joe Hansen, Keira L. Hum, Julia P. Nielsen, Kate F. Pearson, Shania Ramharrack-Maharaj, Deana M. Schwarz, Elli Papangelakis, Carolyn H. Eyles","doi":"10.12789/geocanj.2023.50.198","DOIUrl":"https://doi.org/10.12789/geocanj.2023.50.198","url":null,"abstract":"As geoscientists, we must prioritize improving our ability to communicate science to the public. Effective geoscience communication enables communities to understand how geological processes have shaped our planet and make informed decisions about Earth’s future. However, geoscience research outputs have traditionally been published in peer-reviewed journals and presented at academic conferences. Consequently, essential information about local geology is rarely available in accessible, open access, and engaging formats. Here, we propose virtual field trips, or ‘GeoTrails’, as a possible solution to address the disconnect between geoscience research and public knowledge by improving our communication to the public. This initiative is largely driven by undergraduate students, who identify points of geological interest along selected hiking trails, write concise descriptions derived from scientific sources (e.g. longer peer-reviewed articles and government reports), and collect field data (e.g. 3-D LiDAR models, drone photography) to illustrate the characteristics of these geological features. The goal of the project is to communicate the importance of local geology on our environment and to raise awareness of how changing climates could affect us in the future; this information can empower communities to make better, more informed planning decisions. The creation of GeoTrails along the Niagara Escarpment offers a promising strategy to highlight the role of geoscientists and to engage the public in our ongoing research that aims to showcase Canada’s geoheritage.","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135743927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Critical Minerals in the Context of Canada: Concepts, Challenges and Contradictions","authors":"Andrew Kerr","doi":"10.12789/geocanj.2023.50.199","DOIUrl":"https://doi.org/10.12789/geocanj.2023.50.199","url":null,"abstract":"Increased use of renewable energy, coupled with electrification of the economy, is considered important in efforts to limit future climate change. This energy transition is predicted to increase demands for some commodities, many of which are now labelled as critical mineral. The quest for such commodities is now a persistent theme for the resource industry and emerging government policies. This review for non-specialists explains several key concepts but also explores some challenges and apparent contradictions in the context of Canada. Canada now has a list of 31 critical minerals, but this includes some major commodities for which domestic production is significant and supply risk is low. The differences between our list and those of other jurisdictions reflect our more specific definitions. Most other commodities on Canada’s list are also identified by other countries and some are specifically linked to the energy transition. These include cobalt, lithium, manganese, nickel, graphite and vanadium (used in electric vehicle batteries and static energy storage), rare earth elements (REE; used for magnets in EV motors and wind turbines) and some rarer elements (e.g. germanium, gallium, indium and tellurium) used in photovoltaic (solar) energy systems. Some of these are potential primary products (e.g. lithium, graphite and REE) but many others (e.g. cobalt, platinum group elements and the photovoltaic elements) are byproducts from the production of major commodities, notably nickel, copper and zinc. The REE represent coproducts that are closely associated in nature and very hard to separate from each other; they are produced as a group. There are some specific challenges in exploring for and developing critical mineral resources. The end-use technology driving demand evolves on a timescale of years, but mineral exploration and development now typically take multiple decades. Material substitutions and unpredictable developments in technology complicate the exact prediction of future demands. The forecasts of overall relative demand growth are impressive, but for some key commodities global production will remain small in absolute terms, which may limit the potential for new discoveries. Simple measures of grade and tonnage are not always guarantees of viability, because deposits of some commodities (e.g. the REE) are mineralogically complex. Byproduct commodities cannot be produced in isolation, and many of these are only extracted in smelting and refining. Domestic production of these commodities is effectively lost if concentrates are exported for processing. The emissions and environmental impacts associated with production of critical mineral resources will also become important if such activity is to be linked to wider climate goals. This may present challenges in northern Canada, where renewable or low-carbon energy options are limited. Most draft Land Use Plans in the north presently emphasize large-scale land conservation, which could lim","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135743763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Igneous Rock Associations 29. The Nenana Magnetitite Lava Flow, Alaska Range, Alaska","authors":"S. Reidel, M. Ross, J. Kasbohm","doi":"10.12789/geocanj.2023.50.197","DOIUrl":"https://doi.org/10.12789/geocanj.2023.50.197","url":null,"abstract":"Magnetitite deposits like El Laco (Chile) are rare and have controversial origins. An unusual magnetitite lava flow overlying a rhyolite unit occurs in the north-central Alaska Range and originally covered ~ 750 km2 of the Miocene Nenana basin. Dating of the rhyolite and relationships between the magnetitite and sedimentary rocks indicate that both are of Late Miocene age. The magnetitite flow is mainly magnetite with some post-eruptive alteration to hematite. Both the rhyolite flow and the magnetitite flow are vesicular, but the magnetitite flow also has small, millimetre-scale columnar jointing. The vesicular zones in the magnetitite flow grade into massive rock on the scale of a thin section, suggesting a degassing lava origin. Samples of the magnetitite flow contain between 12 and 26 wt.% SiO2 and between 45 and 75 wt.% FeO. Rare earth elements (REE) and trace elements from the magnetitite and rhyolite have similar patterns but with lesser abundance in the magnetitite. Both the rhyolite and the magnetitite have light-REE-enriched REE profiles with negative Eu anomalies. Electron microscopic analysis shows that most of the silica and trace element content of the magnetitite flow comes from very finely disseminated silicate minerals and glass in the magnetite. This suggests that the magnetitite was derived from a magma that had undergone unmixing into a silica-rich phase and an iron-rich phase prior to its eruption. Fractures and vesicles within the magnetitite flow contain minor rhyolitic glass and minerals suggesting that the rhyolite magma invaded columnar joints in the solidified magnetitite flow, and is a subvolcanic sill-like body at the studied locality. The magnetitite flow erupted prior to the emplacement of the rhyolite, which may be extrusive on a regional scale. The features of the Nenana magnetitite, and its geological relationships, are consistent with genetic models that invoke unmixing of magma into immiscible Fe-rich and Si-rich liquids during ascent.","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46859735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heritage Stone 9. Tyndall Stone, Canada’s First Global Heritage Stone Resource: Geology, Paleontology, Ichnology and Architecture","authors":"B. Pratt, G. Young","doi":"10.12789/geocanj.2023.50.196","DOIUrl":"https://doi.org/10.12789/geocanj.2023.50.196","url":null,"abstract":"Tyndall Stone is a distinctively mottled and strikingly fossiliferous dolomitic limestone that has been widely used for over a century in Canada, especially in the Prairie Provinces. It comprises 6–8 m within the lower part of the 43 m thick Selkirk Member of the Red River Formation, of Late Ordovician (Katian) age. It has been quarried exclusively at Garson, Manitoba, 37 km northeast of Winnipeg, since about 1895, and for the past half-century extraction has been carried out solely by Gillis Quarries Ltd. The upper beds tend to be more buff-coloured than the grey lower beds, as a result of groundwater weathering. Tyndall Stone, mostly with a smooth or sawn finish, has been put to a wide variety of uses, including exterior and interior cladding with coursed and random ashlar, and window casements and doorways. Split face finish and random ashlar using varicoloured blocks split along stylolites have become popular for commercial and residential buildings, respectively. Tyndall Stone lends itself to carving as well, being used in columns, coats of arms and sculptures. Many prominent buildings have been constructed using Tyndall Stone, including the provincial legislative buildings of Saskatchewan and Manitoba, the interior of the Centre Block of the House of Commons in Ottawa, courthouses, land titles buildings, post offices and other public buildings, along with train stations, banks, churches, department stores, museums, office buildings and university buildings. These exhibit a variety of architectural styles, from Beaux Arts to Art Deco, Châteauesque to Brutalist. The Canadian Museum of History and the Canadian Museum for Human Rights are two notable Expressionist buildings.   The lower Selkirk Member is massive and consists of bioturbated, bioclastic wackestone to packstone, rich in crinoid ossicles. It was deposited in a low-energy marine environment within the photic zone, on the present-day eastern side of the shallow Williston Basin, which was part of the vast equatorial epicontinental sea that covered much of Laurentia at the time. Scattered thin bioclastic grainstone lenses record episodic, higher energy events. Tyndall Stone is spectacularly fossiliferous, and slabs bearing fossils have become increasingly popular. The most common macrofossils are receptaculitids, followed by corals, stromatoporoid sponges, nautiloid cephalopods, and gastropods. The relative abundance of the macrofossils varies stratigraphically, suggesting that subtle environmental changes took place over time.    The distinctive mottles—‘tapestry’ in the trade—have been regarded as dolomitized burrows assigned to Thalassinoides and long thought to have been networks of galleries likely made by arthropods. In detail, however, the bioclastic muddy sediment underwent a protracted history of bioturbation, and the large burrows were mostly horizontal back-filled features that were never empty. They can be assigned to Planolites. The matrix and the sediment filling them wer","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47473723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}