Geoscience Canada最新文献

{"title":"Reading the Rocks Reloaded: A Celebration of the Geological Survey of Canada 175th Anniversary with a View to the Future","authors":"D. Lebel","doi":"10.12789/GEOCANJ.2018.45.140","DOIUrl":"https://doi.org/10.12789/GEOCANJ.2018.45.140","url":null,"abstract":"In 2017, the Geological Survey of Canada (GSC) celebrated its 175th anniversary, just as the 150th anniversary of the Canadian Confederation was celebrated. In many ways, the development of this organization over its long history parallels the exploration and economic development of our country, and these two stories are very closely intertwined. In its early days, the GSC was involved in charting the essential geography of Canada’s landmass, and early GSC geologists were involved in some of the discoveries that laid a foundation for our modern resource economy. In the 21st century, the GSC remains at the forefront of geoscience research across the nation, collaborating with many Provincial and Territorial partners and also with academic and industry researchers to expand our knowledge and find ways to sustainably develop our resources. Like all organizations, GSC has evolved over the years, and must continue to do so in response to technological innovation and societal demands. This article provides an overview of where we came from, where we have been, where we are today, and where we hope to go in the future. It is hoped that it will provide a starting point for other articles highlighting some of GSC’s more specific scientific contributions over the years, and exploring some of the many characters who colourfully populate its long history.RÉSUMÉEn 2017, la Commission géologique du Canada (CGC) a célébré son 175ème anniversaire, alors que l’on célébrait le 150ème anniversaire de la confédération canadienne. De plusieurs façons, le développement de cette organisation au cours de sa longue histoire suit en parallèle l’exploration et le développement économique de notre pays, et ces deux histoires sont très intimement inter-reliées. Dans ses premiers jours, la CGC a été impliquée dans la cartographie géographique essentielle de la masse continentale du Canada, et ses premiers géologues de la CGC ont été impliqués dans certaines des découvertes qui ont jeté les bases de notre économie moderne des ressources. Au XXIe siècle, la CGC reste à l’avant-garde de la recherche géoscientifique à travers le pays et collabore avec de nombreux partenaires provinciaux et territoriaux ainsi qu’avec des chercheurs universitaires et industriels afin d’élargir nos connaissances et de trouver des moyens de développer nos ressources de manière durable. Comme toutes les organisations, la CGC a évolué au cours des années, et doit continuer de le faire en réponse à l’innovation technologique et aux besoins sociétaux. Cet article fourni un aperçu de nos origines, de notre cheminement, de notre situation actuelle et de nos objectifs futurs. On espère que cela fournira un point de départ pour d’autres articles mettant en lumière certaines des contributions scientifiques plus spécifiques de la CGC au fil des ans et explorant certains des nombreux personnages qui peuplent de manière colorée sa longue histoire.","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44800907","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":"Québec 2019: GAC–MAC–IAH Joint Annual Meeting Field Trips","authors":"S. Castonguay","doi":"10.12789/GEOCANJ.2018.45.141","DOIUrl":"https://doi.org/10.12789/GEOCANJ.2018.45.141","url":null,"abstract":"WHERE GEOSCIENCES CONVERGE The Geological Association of Canada (GAC), the Mineralogical Association of Canada (MAC) and the Canadian National Chapter of the International Association of Hydrogeologists (IAH-CNC) invite geoscientists to their joint annual meeting in historic Quebec City, a UNESCO World-Heritage site. Participants will have the opportunity to visit and discover the warmth and charms of Quebec City and explore its many attractive natural sites, where converge three geological provinces: the Appalachians, the St. Lawrence Platform, and the Grenville. The conference’s theme “Where Geosciences Converge” aspires to promote collaboration and stimulating discussion among geoscientists during symposia, special sessions, short courses and field trips, under the umbrella of four multidisciplinary themes:","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42933040","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 23. The Bushveld Complex, South Africa: New Insights and Paradigms","authors":"S. Prevec","doi":"10.12789/GEOCANJ.2018.45.138","DOIUrl":"https://doi.org/10.12789/GEOCANJ.2018.45.138","url":null,"abstract":"SUMMARYThe Bushveld Complex has continued to serve as the basis for study into the fundamental nature of petrological processes for layered intrusion formation and for oxide and sulphide hosted Platinum Group Element (PGE)–Cu–Ni ore deposits. These studies have included discoveries in terms of the physical extent of Bushveld magmatism, both laterally and internally. Lateral variations in the mafic to ultramafic Rustenburg Layered Suite of the Northern Lobe of the complex have also revealed petrologically distinctive Upper Critical Zone equivalent rocks (the so-called Flatreef) with enhanced contamination and mineralization traits that reflect a transition between Eastern and Western Lobe equivalent stratigraphy and Platreef-style complexity. Traditional magma mixing models have been re-examined in light of radiogenic isotopic evidence for crustal involvement early in the chromite precipitation or formation process, combined with evidence for associated heterogeneous fluid contents, cryptic layering profiles, and textural evidence. A wide variety of alternative ore-genesis models have been proposed as a consequence. The fundamental mechanics of magma chamber processes and the existence of the magma chamber as an entity have been called into question through various lines of evidence which have promoted the concept of progressive emplacement of the complex as a stack of not-necessarily-quite-sequentially intruded sills (with or without significant quantities of transported phenocrysts), emplaced into variably crystallized and compacted crystal-liquid mush mixtures, modified by compaction-driven late magmatic fluid (silicate and aqueous) activity. Alternatively, petrological and geochemical observations have been used to discount these interpretations in favour of more conventional cooling and gravity-driven accumulation of silicate and ore minerals in a large, liquid-dominated system.RÉSUMÉLe complexe de Bushveld a demeuré à la base d’études sur la nature fondamentale des processus pétrologiques de formation d’intrusions litées et des gîtes des éléments du groupe platine (ÉGP)-Cu-Ni hébergés dans les oxydes et les sulfures. Ces études ont comporté des découvertes sur l’étendue physique, à la fois latérale et interne, du magmatisme de Bushveld. Les variations latérales de la suite stratifiée et mafique à ultramafique Rustenburg du lobe nord du complexe ont également révélé des roches équivalentes pétrologiquement distinctes de la zone critique supérieure (le communément désigné Flatreef) avec des traits de contamination et de minéralisation accrus qui reflètent une transition entre la stratigraphie équivalente des lobes est et ouest et la complexité de type Platreef. Les modèles traditionnels de mélanges magmatiques ont été réexaminés à la lumière de preuves isotopiques radiogéniques indiquant une implication de la croûte au début du processus de précipitation ou de formation de la chromite, combinées à des preuves de contenu fluide hétérogène assoc","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43710810","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":"Economic Geology Models 2. Tantalum and Niobium: Deposits, Resources, Exploration Methods and Market – A Primer for Geoscientists","authors":"G. Simandl, R. Burt, D. Trueman, S. Paradis","doi":"10.12789/GEOCANJ.2018.45.135","DOIUrl":"https://doi.org/10.12789/GEOCANJ.2018.45.135","url":null,"abstract":"The world’s main tantalum (Ta) resources are in pegmatites (e.g. Wodgina, Australia), rare element-enriched granites (e.g. Abu Dabbab, Egypt), peralkaline complexes (e.g. Nechalacho, Canada), weathered crusts overlying the previously mentioned deposit types, and in placers. Niobium (Nb) resources with the highest economic potential are in weathered crusts that overlie carbonatite complexes (e.g. Catalão I and II, Brazil). Brazil accounts for 90% of the global Nb mine production with another 9% coming from the Niobec Mine, Canada (a hard-rock underground mine). However, at least 17 undeveloped carbonatite complexes outside of Brazil have NI-43-101 compliant Nb resource estimates (e.g. Aley carbonatite, Canada). Concentrates from most carbonatites are used to produce ferroniobium (Fe–Nb alloy), and Ta is not recovered. The Ta and Nb contents of some carbonatites (e.g. Upper Fir deposit and Crevier dyke, Canada) are of the same order of magnitude as that of pegmatite ores; however, concentrates from carbonatites have a higher Nb/Ta ratio. Historically, 10–12% Ta2O5 in Nb concentrates has not been recovered in ‘western’ smelters because of the hydrofluoric acid cost. Western countries perceive Ta and Nb supplies to be at risk. Tantalum market downturns resulted in several mines in Australia and Canada closing, at least temporarily, and a resultant shortfall has been filled by what is now recognized as ‘conflict-free columbite-tantalite’ from Central Africa. The lack of ore will not be a key factor in future Ta and Nb supply disruption. For example, more than 280 Nb- and 160 Ta-bearing occurrences are known in Canada alone, and more resources will likely to be discovered as geophysical and geochemical exploration methods are optimized.RÉSUMÉLes principales sources mondiales en tantale (Ta) sont les pegmatites (par ex. Wodgina, Australie), les granites enrichis en éléments rares (par ex. Abu Dabbab, Égypte), les complexes hyperalcalins (par ex. Nechalacho, Canada), les croûtes altérées recouvrant les types de gisements déjà mentionnés, et les placers. Les sources en niobium (Nb) ayant le meilleur potentiel économique se trouvent dans les croûtes altérées qui recouvrent les complexes de carbonatite (par ex. Catalão I et II, Brésil). Le Brésil est la source de 90% de la production minière mondiale de Nb, et 9% provient de la mine Niobec, au Canada (une mine souterraine). Cela dit, il existe au moins 17 complexes de carbonatite non développés à l'extérieur du Brésil dont les estimations de ressources en Nb sont conformes à la norme NI-43-101 (par ex. Aley carbonatite, Canada). Les concentrés de la plupart des carbonatites sont utilisés pour produire du ferroniobium (alliage Fe-Nb), et le Ta n'est pas récupéré. Les teneurs en Ta et Nb de certaines carbonatites (par ex. le gisement de Upper Fir et le dyke Crevier, Canada) sont du même ordre de grandeur que celles des minerais depegmatite; cependant, les concentrés de carbonatites ont une proportion Nb/Ta pl","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44055046","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 22. Experimental Petrology: Methods, Examples, and Applications","authors":"C. Shaw","doi":"10.12789/GEOCANJ.2018.45.134","DOIUrl":"https://doi.org/10.12789/GEOCANJ.2018.45.134","url":null,"abstract":"Experiments are an important source of basic information in petrology, from thermodynamic data used to develop predictive models to physical property data used to understand magma ascent and eruption. Since we all use experimental data in our work as geoscientists, it is important that we have a basic understanding of the methods used to prepare and perform experiments on rocks and minerals and their synthetic analogues. In this review I examine how the observational science of geology changed in the late 1800’s with the development of the interdisciplinary science of physical chemistry. The second part of the paper discusses what factors need to be considered in designing an experimental study; it focuses particularly on the problems of reaching equilibrium on the short timescales available in the laboratory. In the final section, I give four examples of geological problems that have been solved using experimental methods and make some suggestions about the directions that future experimental campaigns might take.RÉSUMÉL’expérimentation est une source importante d’information de base en pétrologie, qu’il s’agisse de données thermodynamiques pour développer des modèles prédictifs, ou des propriétés physiques utilisés pour comprendre la montée et l’éruption d’un magma. Puisque nous utilisons tous des données expérimentales dans notre travail de géoscientifique, il est important que nous ayons une compréhension minimale des méthodes utilisées pour préparer et réaliser des expériences sur les roches, les minéraux et leurs analogues de synthèse. Dans la présente étude, je me suis penché sur les changements survenus en science d’observation qu’est la géologie, à la fin des années 1800, avec le développement de la science interdisciplinaire de la chimie physique. La deuxième partie de l’article traite des facteurs à prendre en compte dans la conception d’une étude expérimentale; elle porte en particulier sur les problèmes d’atteinte d’un équilibre sur les temps courts du laboratoire. Dans la dernière section, je donne quatre exemples de problèmes géologiques qui ont été résolus à l’aide de méthodes expérimentales, et je fais des suggestions sur des orientations qui pourraient être adoptées lors de campagnes expérimentales à venir.","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45330224","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":"EON-ROSE and the Canadian Cordillera Array – Building Bridges to Span Earth System Science in Canada","authors":"K. Boggs, R. Aster, P. Audet, G. Brunet, R. Clowes, Catherine de Groot-Hedlin, E. Donovan, D. Eaton, J. Elliott, J. Freymueller, M. Hedlin, R. Hyndman, T. James, P. Kushner, K. Morell, C. Rowe, D. Schutt, M. Sideris, M. Ulmi, F. Vernon, N. West","doi":"10.12789/GEOCANJ.2018.45.136","DOIUrl":"https://doi.org/10.12789/GEOCANJ.2018.45.136","url":null,"abstract":"EON-ROSE (Earth-System Observing Network - Réseau d’Observation du Système terrestrE) is a new initiative for a pan-Canadian research collaboration to holistically examine Earth systems from the ionosphere into the core. The Canadian Cordillera Array (CC Array) is the pilot phase, and will extend across the Cordillera from the Beaufort Sea to the U.S. border. The vision for EON-ROSE is to install a network of telemetered observatories to monitor solid Earth, environmental and atmospheric processes. EON-ROSE is an inclusive, combined effort of Canadian universities, federal, provincial and territorial government agencies, industry, and international collaborators. Brainstorming sessions and several workshops have been held since May 2016. The first station will be installed at Kluane Lake Research Station in southwestern Yukon during the summer of 2018. The purpose of this report is to provide a framework for continued discussion and development.RÉSUMÉEON-ROSE (Earth-System Observing Network - Réseau d’Observation du Système terrestrE) est une nouvelle initiative de collaboration de recherche pancanadienne visant à étudier de manière holistique les systèmes terrestres, depuis l’ionosphère jusqu’au noyau. Le Réseau canadien de la cordillère (CC Array) en est la phase pilote, laquelle couvrira toute la Cordillère, de la mer de Beaufort jusqu’à la frontière étasunienne. L’objectif d’EON-ROSE est d’installer un réseau d’observatoires télémétriques pour suivre en continu les processusterrestres, environnementaux et atmosphériques. EON-ROSE est un effort combiné et inclusif des universités canadiennes, des organismes gouvernementaux fédéraux, provinciaux et territoriaux, de l’industrie et de collaborateurs internationaux. Des séances de remue-méninges et plusieurs ateliers ont été tenus depuis mai 2016. La première station sera installée à la station de recherche du lac Kluane, dans le sud-ouest du Yukon, au cours de l’été 2018. Le but du présent rapport est de fournir un cadre de discussion et de développement continu.","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41244964","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":"Vancouver 2018: RFG 2018 / CIM–GAC–MAC Annual Joint Meeting Field Trips","authors":"D. Gibson","doi":"10.12789/GEOCANJ.2018.45.131","DOIUrl":"https://doi.org/10.12789/GEOCANJ.2018.45.131","url":null,"abstract":"","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41998938","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":"Albert Peter Low in Labrador— A Tale of Iron and Irony","authors":"D. Wilton","doi":"10.12789/GEOCANJ.2018.45.130","DOIUrl":"https://doi.org/10.12789/GEOCANJ.2018.45.130","url":null,"abstract":"In 1893–1894, Albert Peter Low of the Geological Survey of Canada, along with D.I.V. Eaton and four indigenous assistants explored the Labrador Peninsula, then perceived as one of the last great unexplored wilderness areas of North America. The expedition left Lake St. John (now Lac St. Jean) on June 17, 1893, canoeing across the northeastern edge of the North American continent, arriving at Fort Chimo (now Kuujjuaq) on August 27, 1893. They departed Fort Chimo by steamer for Rigolet on the Labrador coast and the Hudson Bay Company post at North West River in the fall of 1893. On March 6, 1894 the party started up the Grand (now Churchill) River continuing through large central lakes into the Ashuanipi river system in western Labrador, then out via the Attikonak River to the Romaine River and finally the Saint Jean river system to arrive at Mingan on the north shore of the St. Lawrence River on August 23, 1894. Low described their fifteen-month journey as having covered over 8700 km including 1600 km on foot, over 4700 km in canoe, 800 km by dog team and 1600 km by steamer. The report from the expedition provides a compendium on the natural history of the region as well as the first geological maps. In terms of economic and scientific results, the greatest was documentation of the vast iron ore deposits of western Labrador; a world-class mining district that has been producing for sixty-three years since 1954. Low’s account also provides details on the essence of such an epic journey, which stands as a classic in the annals of Canadian geological surveying.RESUMEEn 1893–1894, Albert Peter Low de la Commission geologique du Canada, accompagne du D.I.V. Eaton et quatre assistants autochtones ont explore la peninsule du Labrador, alors percue comme l'une des dernieres grandes etendues sauvages inexplorees d’Amerique du Nord. L’equipe a quitte le Lake St. John (aujourd'hui le lac Saint-Jean) le 17 juin 1893, a traverse la bordure nord-est du continent nord-americain en canoe, et est arrive a Fort Chimo (aujourd'hui Kuujjuaq) le 27 aout 1893. A l'automne de 1893, ils ont quitte Fort Chimo a bord d'un vapeur pour Rigolet, sur la cote du Labrador, et le poste de la Compagnie de la Baie d'Hudson sur la riviere North West. Le 6 mars 1894, les membres de l'equipe ont remonte la riviere Grand (aujourd'hui Churchill), puis a travers les grands lacs centraux jusqu'au bassin de la riviere Ashuanipi, dans l'ouest du Labrador, puis, par la riviere Attikonak jusqu' a la riviere Romaine et, enfin, le reseau de la riviere Saint-Jean jusqu’a Mingan, sur la rive nord du fleuve Saint-Laurent, le 23 aout 1894. L’excursion decrite par Low a dure quinze mois et parcouru plus de 8700 km dont 1600 km a pied, plus de 4700 km en canoe, 800 km en attelage de chiens et 1600 km en bateau a vapeur. Le rapport de l'expedition constitue un recueil sur l'histoire naturelle de la region ainsi que des premieres cartes geologiques. En ce qui concerne les repercussions economiques et s","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43666893","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":"Classic Rock Tours 1. Hutton’s Unconformity at Siccar Point, Scotland: A Guide for Visiting the Shrine on the Abyss of Time","authors":"A. Kerr","doi":"10.12789/GEOCANJ.2018.45.129","DOIUrl":"https://doi.org/10.12789/GEOCANJ.2018.45.129","url":null,"abstract":"The angular unconformity at Siccar Point in Scotland is one of the most famous localities in the history of geology. At this spot, steeply dipping, folded turbiditic sandstone of early Silurian age is clearly overlain by subhorizontal red conglomerate, breccia and sandstone of late Devonian age. Siccar Point was not the first unconformity ever to be described or illustrated, but it is unquestionably one of the most spectacular and informative that geologists are likely to see. In June of 1788, a famous excursion by James Hutton, John Playfair and Sir James Hall first discovered this striking evidence for the cyclic nature of geological processes and the probable antiquity of the Earth. Contrary to myth, it was likely not the inspiration for Hutton’s famous phrase no vestige of a beginning, no prospect of an end, but Playfair’s metaphor of looking so far into the abyss of time is forever associated with this place. Siccar Point influenced many other geologists, including the young Charles Lyell, who would eventually bring the ideas of James Hutton together with those of William Smith, to build the uniformitarian paradigm that founded modern geology. Lyell’s writings would in turn influence the young Charles Darwin in his search for the reality and causes of evolution. Siccar Point is easy to visit from the historic and vibrant city of Edinburgh, and such a pilgrimage is easily combined with other sights of geological or cultural interest. Visiting the shrine involves a short coastal hike in one of the most beautiful parts of Scotland. This article combines practical advice for would-be pilgrims to Siccar Point with some historical context about its pivotal role in the development of geological ideas in the enlightenment of the late 18th and early 19th centuries.RESUMELa discordance angulaire de Siccar Point en Ecosse est l'une des localites les plus celebres de l'histoire de la geologie. A cet endroit, un gres turbiditique plisse a fort pendage du debut du Silurien est recouvert de conglomerats rouges subhorizontaux, de breches et d’un gres de la fin du Devonien. Siccar Point n'est pas la premiere discordance qui ait ete decrite ou illustree, mais c'est sans conteste l'une des plus spectaculaires et revelatrices que les geologues puissent voir. En juin 1788, avec leur celebre excursion, James Hutton, John Playfair et Sir James Hall ont decouvert cette preuve frappante de la nature cyclique des processus geologiques et de l`anciennete probable de la Terre. Contrairement a ce qu'on croit, ce n'est probablement pas la fameuse phrase de Hutton « aucun vestige d'un debut, aucune perspective de fin », mais la metaphore de Playfair « voir si loin dans l'abime du temps » qui est a jamais associee a ce lieu. Siccar Point a influence de nombreux autres geologues, y compris le jeune Charles Lyell, qui a fini par reunir les idees de James Hutton et celles de William Smith qui ont defini le paradigme uniformitariste, devenu le fondement de la geologie moderne.","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42518780","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":"ROCKS, RIDGES, AND RIVERS: Geological Wonders of Banff, Yoho, and Jasper National Parks. A Roadside Tour Guide","authors":"A. Kerr","doi":"10.12789/GEOCANJ.2018.45.132","DOIUrl":"https://doi.org/10.12789/GEOCANJ.2018.45.132","url":null,"abstract":"","PeriodicalId":55106,"journal":{"name":"Geoscience Canada","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44704296","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}