33 research outputs found

    Great Mining Camps of Canada 8. The Bathurst Mining Camp, New Brunswick, Part 2: Mining History and Contributions to Society

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    In the Bathurst Mining Camp (BMC), 12 of the 45 known massive sulphide deposits were mined between 1957 and 2013; one was mined for iron prior to 1950, whereas three others had development work but no production. Eleven of the deposits were mined for base metals for a total production of approximately 179 Mt, with an average grade of 3.12% Pb, 7.91% Zn, 0.47% Cu, and 93.9 g/t Ag. The other deposit was solely mined for gold, present in gossan above massive sulphide, producing approximately one million tonnes grading 1.79 g/t Au. Three of the 11 mined base-metal deposits also had a gossan cap, from which gold was extracted. In 2012, the value of production from the Bathurst Mining Camp exceeded 670millionandaccountedfor58percentoftotalmineralproductioninNewBrunswick.Base−metalproductionstartedintheBMCin1957fromdepositsatHeathSteeleMines,followedbyWedgein1962,BrunswickNo.12in1964,BrunswickNo.6in1965,Caribouin1970,MurrayBrook,StratmatBoundaryandStratmatN−5in1989,CaptainNorthExtensionin1990,andlastly,HalfMileLakein2012.TheonlymineincontinuousproductionformostofthistimewasBrunswickNo.12.Duringits49−yearlifetime(1964–2013),itproduced136,643,367tonnesoforegrading3.44670 million and accounted for 58 percent of total mineral production in New Brunswick.Base-metal production started in the BMC in 1957 from deposits at Heath Steele Mines, followed by Wedge in 1962, Brunswick No. 12 in 1964, Brunswick No. 6 in 1965, Caribou in 1970, Murray Brook, Stratmat Boundary and Stratmat N-5 in 1989, Captain North Extension in 1990, and lastly, Half Mile Lake in 2012. The only mine in continuous production for most of this time was Brunswick No. 12. During its 49-year lifetime (1964–2013), it produced 136,643,367 tonnes of ore grading 3.44% Pb, 8.74% Zn, 0.37% Cu, and 102.2 g/t Ag, making it one of the largest underground base-metal mines in the world.The BMC remains important to New Brunswick and Canada because of its contributions to economic development, environmental measures, infrastructure, mining innovations, and society in general. The economic value of metals recovered from Brunswick No. 12 alone, in today’s prices exceeds 46 billion. Adding to this figure is production from the other mines in the BMC, along with money injected into the local economy from annual exploration expenditures (100s of 1000speryear)over60years.SeveralenvironmentalmeasureswereinitiatedintheBMC,includingtherequirementtobecleanshavenandcarryaportablerespirator(nowappliedtoallminesinCanada);waystotreatacidminedrainageandthethiosaltproblemthatcomesfromthemillingprocess;andpioneeringstudiestodevelopandinstallstreamside−incubationboxesforAtlanticSalmoneggsintheNepisiguitRiver,whichboostedsurvivalratestoover901000s per year) over 60 years. Several environmental measures were initiated in the BMC, including the requirement to be clean shaven and carry a portable respirator (now applied to all mines in Canada); ways to treat acid mine drainage and the thiosalt problem that comes from the milling process; and pioneering studies to develop and install streamside-incubation boxes for Atlantic Salmon eggs in the Nepisiguit River, which boosted survival rates to over 90%. Regarding infrastructure, provincial highways 180 and 430 would not exist if not for the discovery of the BMC; nor would the lead smelter and deep-water port at Belledune. Mining innovations are too numerous to list in this summary, so the reader is referred to the main text. Regarding social effects, the new opportunities, new wealth, and training provided by the mineral industry dramatically changed the living standards and social fabric of northern New Brunswick. What had been a largely poor, rural society, mostly dependent upon the fishing and forestry industries, became a thriving modern community. Also, untold numbers of engineers, geologists, miners, and prospectors `cut their teeth’ in the BMC, and many of them have gone on to make their mark in other parts of Canada and the world.Dans le camp minier de Bathurst (CMB), 12 des 45 gisements de sulfures massifs connus ont Ă©tĂ© exploitĂ©s entre 1957 et 2013; un de ces gisements a Ă©tĂ© exploitĂ© pour le fer avant 1950, tandis que trois autres Ă©taient en dĂ©veloppement mais pas en production. Onze gisements ont Ă©tĂ© exploitĂ©s pour des mĂ©taux communs pour une production totale d'environ 179 Mt, avec une teneur moyenne de 3,12% Pb, 7,91% Zn, 0,47% Cu et 93,9 g/t Ag. L'autre gisement Ă©tait uniquement exploitĂ© pour l'or, prĂ©sent dans le gossan au-dessus du sulfure massif, produisant environ un million de tonnes titrant 1,79 g/t Au. Trois des 11 gisements de mĂ©taux communs exploitĂ©s avaient Ă©galement un gossan, d'oĂč l'or Ă©tait extrait. En 2012, la valeur de la production du camp minier de Bathurst dĂ©passait 670 millions de dollars et reprĂ©sentait 58% de la production minĂ©rale totale au Nouveau-Brunswick.La production de mĂ©taux communs a commencĂ© dans le CMB en 1957 Ă  partir des gisements de Heath Steele Mines, suivie de Wedge en 1962, Brunswick no 12 en 1964, Brunswick no 6 en 1965, Caribou en 1970, Murray Brook, Stratmat Boundary et Stratmat N- 5 en 1989, Captain North Extension en 1990, et enfin Half Mile Lake en 2012. La seule mine en production continue pendant la majeure partie de cette pĂ©riode Ă©tait Brunswick no 12. Au cours de sa durĂ©e de vie de 49 ans (1964–2013), elle a produit 136 643 367 tonnes de minerai titrant 3,44% Pb, 8,74% Zn, 0,37% Cu et 102,2 g/t Ag, ce qui en fait l'une des plus grandes mines souterraines de mĂ©taux communs au monde.Le CMB demeure important pour le Nouveau-Brunswick et le Canada en raison de sa contribution au dĂ©veloppement Ă©conomique, aux mesures environnementales, Ă  l'infrastructure, aux innovations miniĂšres et Ă  la sociĂ©tĂ© en gĂ©nĂ©ral. La valeur Ă©conomique des mĂ©taux rĂ©cupĂ©rĂ©s du seul gisement Brunswick n° 12, aux prix d’aujourd’hui, dĂ©passe 46 milliards de dollars. S'ajoute Ă  ce chiffre la production des autres mines du CMB, ainsi que l'argent injectĂ© dans l'Ă©conomie locale par les dĂ©penses d'exploration annuelles (des centaines Ă  des milliers de par an) sur 60 ans. Plusieurs mesures environnementales ont Ă©tĂ© lancĂ©es dans le CMB, y compris l'exigence d'ĂȘtre rasĂ© de prĂšs et de porter un respirateur portatif (maintenant appliquĂ© Ă  toutes les mines au Canada); les moyens de traitement des effluents miniers acides et le problĂšme des thiosels qui proviennent du processus de broyage; et les Ă©tudes pionniĂšres pour dĂ©velopper et installer des boĂźtes d'incubation en bord de riviĂšre pour les Ɠufs de saumon de l'Atlantique dans la riviĂšre Nepisiguit, ce qui a fait passer les taux de survie Ă  plus de 90%. En ce qui concerne les infrastructures, les routes provinciales 180 et 430 n'existeraient pas sans la dĂ©couverte du CMB; la fonderie de plomb et le port en eau profonde de Belledune non plus. Les innovations miniĂšres sont trop nombreuses pour ĂȘtre Ă©numĂ©rĂ©es dans ce rĂ©sumĂ©, le lecteur est donc renvoyĂ© au texte principal. En ce qui concerne les effets sociaux, les nouvelles possibilitĂ©s, la nouvelle richesse et la formation offertes par l'industrie miniĂšre ont radicalement changĂ© le niveau de vie et le tissu social du nord du Nouveau-Brunswick. Ce qui avait Ă©tĂ© une sociĂ©tĂ© rurale en grande partie pauvre, principalement tributaire des industries de la pĂȘche et de la sylviculture, est devenu une communautĂ© moderne florissante. De plus, un nombre incalculable d’ingĂ©nieurs, de gĂ©ologues, de mineurs et de prospecteurs «se sont fait les dents» au CMB, et bon nombre d’entre eux ont continuĂ© Ă  faire leurs marques dans d’autres rĂ©gions du Canada et du monde

    A Self-Absorption Census of Cold HI Clouds in the Canadian Galactic Plane Survey

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    We present a 21cm line HI self-absorption (HISA) survey of cold atomic gas within Galactic longitudes 75 to 146 degrees and latitudes -3 to +5 degrees. We identify HISA as spatially and spectrally confined dark HI features and extract it from the surrounding HI emission in the arcminute-resolution Canadian Galactic Plane Survey (CGPS). We compile a catalog of the most significant features in our survey and compare our detections against those in the literature. Within the parameters of our search, we find nearly all previously detected features and identify many new ones. The CGPS shows HISA in much greater detail than any prior survey and allows both new and previously-discovered features to be placed into the larger context of Galactic structure. In space and radial velocity, faint HISA is detected virtually everywhere that the HI emission background is sufficiently bright. This ambient HISA population may arise from small turbulent fluctuations of temperature and velocity in the neutral interstellar medium. By contrast, stronger HISA is organized into discrete complexes, many of which follow a longitude-velocity distribution that suggests they have been made visible by the velocity reversal of the Perseus arm's spiral density wave. The cold HI revealed in this way may have recently passed through the spiral shock and be on its way to forming molecules and, eventually, new stars. This paper is the second in a series examining HISA at high angular resolution. A companion paper (Paper III) describes our HISA search and extraction algorithms in detail.Comment: 44 pages, including 13 figure pages; to appear in June 10 ApJ, volume 626; figure quality significantly reduced for astro-ph; for full resolution, please see http://www.ras.ucalgary.ca/~gibson/hisa/cgps1_survey

    Natural Reward Experience Alters AMPA and NMDA Receptor Distribution and Function in the Nucleus Accumbens

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    Natural reward and drugs of abuse converge upon the mesolimbic system which mediates motivation and reward behaviors. Drugs induce neural adaptations in this system, including transcriptional, morphological, and synaptic changes, which contribute to the development and expression of drug-related memories and addiction. Previously, it has been reported that sexual experience in male rats, a natural reward behavior, induces similar neuroplasticity in the mesolimbic system and affects natural reward and drug-related behavior. The current study determined whether sexual experience causes long-lasting changes in mating, or ionotropic glutamate receptor trafficking or function in the nucleus accumbens (NAc), following 3 different reward abstinence periods: 1 day, 1 week, or 1 month after final mating session. Male Sprague Dawley rats mated during 5 consecutive days (sexual experience) or remained sexually naïve to serve as controls. Sexually experienced males displayed facilitation of initiation and performance of mating at each time point. Next, intracellular and membrane surface expression of N-methyl-D-aspartate (NMDA: NR1 subunit) and α-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA: GluA1, GluA2 subunits) receptors in the NAc was determined using a bis(sulfosuccinimidyl)suberate (BS3) protein cross-linking assay followed by Western Blot analysis. NR1 expression was increased at 1 day abstinence both at surface and intracellular, but decreased at surface at 1 week of abstinence. GluA2 was increased intracellularly at 1 week and increased at the surface after 1 month of abstinence. Finally, whole-cell patch clamp electrophysiological recordings determined reduced AMPA/NMDA ratio of synaptic currents in NAc shell neurons following stimulation of cortical afferents in sexually experienced males after all reward abstinence periods. Together, these data show that sexual experience causes long-term alterations in glutamate receptor expression and function in the NAc. Although not identical, this sex experience-induced neuroplasticity has similarities to that caused by psychostimulants, suggesting common mechanisms for reinforcement of natural and drug reward

    Bacterial endosymbiont Cardinium cSfur genome sequence provides insights for understanding the symbiotic relationship in Sogatella furcifera host

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    Background: Sogatella furcifera is a migratory pest that damages rice plants and causes severe economic losses. Due to its ability to annually migrate long distances, S.furcifera has emerged as a major pest of rice in several Asian countries. Symbiotic relationships of inherited bacteria with terrestrial arthropods have significant implications. The genus Cardinium is present in many types of arthropods, where it influences some host characteristics. We present a report of a newly # identified strain of the bacterial endosymbiont Cardinium cSfur in S. furcifera. Result: From the whole genome of S. furcifera previously sequenced by our laboratory, we assembled the whole genome sequence of Cardinium cSfur. The sequence comprised 1,103,593 bp with a GC content of 39.2%. The phylogenetic tree of the Bacteroides phylum to which Cardinium cSfur belongs suggests that Cardinium cSfur is closely related to the other strains (Cardinium cBtQ1 and cEper1) that are members of the Amoebophilaceae family. Genome comparison between the host-dependent endosymbiont including Cardinium cSfur and freeliving bacteria revealed that the endosymbiont has a smaller genome size and lower GC content, and has lost some genes related to metabolism because of its special environment, which is similar to the genome pattern observed in other insect symbionts. Cardinium cSfur has limited metabolic capability, which makes it less contributive to metabolic and biosynthetic processes in its host. From our findings, we inferred that, to compensate for its limited metabolic capability, Cardinium cSfur harbors a relatively high proportion of transport proteins, which might act as the hub between it and its host. With its acquisition of the whole operon related to biotin synthesis and glycolysis related genes through HGT event, Cardinium cSfur seems to be undergoing changes while establishing a symbiotic relationship with its host. Conclusion: A novel bacterial endosymbiont strain (Cardinium cSfur) has been discovered. A genomic analysis of the endosymbiont in S. furcifera suggests that its genome has undergone certain changes to facilitate its settlement in the host. The envisaged potential reproduction manipulative ability of the new endosymbiont strain in its S. furcifera host has vital implications in designing eco-friendly approaches to combat the insect pest

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Feasibility of preoperative chemotherapy for locally advanced, operable colon cancer: The pilot phase of a randomised controlled trial

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    Summary: Background Preoperative (neoadjuvant) chemotherapy and radiotherapy are more eff ective than similar postoperative treatment for oesophageal, gastric, and rectal cancers, perhaps because of more eff ective micrometastasis eradication and reduced risk of incomplete excision and tumour cell shedding during surgery. The FOxTROT trial aims to investigate the feasibility, safety, and effi cacy of preoperative chemotherapy for colon cancer. Methods In the pilot stage of this randomised controlled trial, 150 patients with radiologically staged locally advanced (T3 with ≄5 mm invasion beyond the muscularis propria or T4) tumours from 35 UK centres were randomly assigned (2:1) to preoperative (three cycles of OxMdG [oxaliplatin 85 mg/mÂČ, l-folinic acid 175 mg, fl uorouracil 400 mg/mÂČ bolus, then 2400 mg/mÂČ by 46 h infusion] repeated at 2-weekly intervals followed by surgery and a further nine cycles of OxMdG) or standard postoperative chemotherapy (12 cycles of OxMdG). Patients with KRAS wild-type tumours were randomly assigned (1:1) to receive panitumumab (6 mg/kg; every 2 weeks with the fi rst 6 weeks of chemotherapy) or not. Treatment allocation was through a central randomisation service using a minimised randomisation procedure including age, radiological T and N stage, site of tumour, and presence of defunctioning colostomy as stratifi cation variables. Primary outcome measures of the pilot phase were feasibility, safety, and tolerance of preoperative therapy, and accuracy of radiological staging. Analysis was by intention to treat. This trial is registered, number ISRCTN 87163246. Findings 96% (95 of 99) of patients started and 89% (85 of 95) completed preoperative chemotherapy with grade 3–4 gastrointestinal toxicity in 7% (seven of 94) of patients. All 99 tumours in the preoperative group were resected, with no signifi cant diff erences in postoperative morbidity between the preoperative and control groups: 14% (14 of 99) versus 12% (six of 51) had complications prolonging hospital stay (p=0·81). 98% (50 of 51) of postoperative chemotherapy patients had T3 or more advanced tumours confi rmed at post-resection pathology compared with 91% (90 of 99) of patients following preoperative chemotherapy (p=0·10). Preoperative therapy resulted in signifi cant downstaging of TNM5 compared with the postoperative group (p=0·04), including two pathological complete responses, apical node involvement (1% [one of 98] vs 20% [ten of 50], p<0·0001), resection margin involvement (4% [ four of 99] vs 20% [ten of 50], p=0·002), and blinded centrally scored tumour regression grading: 31% (29 of 94) vs 2% (one of 46) moderate or greater regression (p=0·0001). Interpretation Preoperative chemotherapy for radiologically staged, locally advanced operable primary colon cancer is feasible with acceptable toxicity and perioperative morbidity. Proceeding to the phase 3 trial, to establish whether the encouraging pathological responses seen with preoperative therapy translates into improved long-term oncological outcome, is appropriate

    Implications of field relations and U-Pb geochronology for the age of gold mineralization and timing of Acadian deformation in northern New Brunswick

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    In the Upsalquitch Forks area (NTS 21 O/10), penetratively deformed sedimentary and volcanic rocks of the Silurian Chaleurs Group and Lower Devonian Dalhousie and Tobique groups were intruded by abundant syn- to post-tectonic dykes and plugs. The Mulligan Gulch porphyry, a hypabyssal felsic intrusion (with an extrusive component ?) emplaced in Upper Silurian sedimentary rocks, has yielded a U-Pb zircon age of 419 ± 1 Ma, whereas the Jerry Ferguson porphyry, a felsic intrusion that intruded Lower Devonian volcanic rocks, has yielded a U-Pb zircon age of 401 ± 1 Ma. The above ages, combined with field relationships, permit the following conclusions: (1) felsic and mafic intrusions in the Upsalquitch Forks area are more or less coeval with volcanic rocks of the Chaleurs, Dalhousie and Tobique groups; (2) most gold occurrences in the area are genetically related to mafic intrusions and, therefore, formed in Late Silurian to Early Devonian time; (3) penetrative deformation in the area was predominantly a Silurian rather than a Devonian process and therefore was not Acadian sensu stricto; (4) Late Silurian to Early Devonian igneous activity occurred in a compressive, rather than an extensional, tectonic setting. R&#xC9;SUM&#xC9; Dans la r&#xE9;gion d'Upsalquitch Forks (SNRC 21 O/10), les roches s&#xE9;dimentaires et volcaniques &#xE0; d&#xE9;formation p&#xE9;n&#xE9;trative du Croupe de Chaleurs (Silurien) et des groupes de Dalhousie et d Trbique (D&#xE9;vonien inf&#xE9;rieur) sont recoup&#xE9;es par d'abondants dykes et culots syn- &#xE0; post-tectoniques. Le porphyre de Mulligan Gulch, une intrusion felsique hypoabyssale (dotce d'une composante extrusive?) emplac&#xE9;e au sein de roches s&#xE9;dimentaires du Silurien sup&#xE9;rieur, a livr&#xE9; un &#xE2;ge U-Pb sur zircons de 419 ± 1 Ma. En revanche, le porphyre de Jerry Ferguson, une intrusion felsique au sein de volcanites du D&#xE9;vonien inf&#xE9;rieur, &#xE0; livr&#xE9; un &#xE2;ge U-Pb sur zircons de 401 ± 1 Ma. Ces &#xE2;ges, combin&#xE9;s aux relations observ&#xE9;es sur le terrain, permettent de conclure que: (1) les intrusions felsiques et mafiques dans la r&#xE9;gion d'Upsalquitch sont plus ou moins synchrones des volcanites des groupes de Chaleurs, Dalhousie et Tobique; (2) la plupart des gites aurif&#xE8;res de cette re&#xE9;ion sont reli&#xE9;s par leur gen&#xE8;se aux intrusions mafiques et, par cons&#xE9;quent, ils se sont form&#xE9;s du Silurien tardif au d&#xE9;but du D&#xE9;vonien; (3) la d&#xE9;formation p&#xE9;n&#xE9;trative dans cette r&#xE9;gion eut lieu sur tout au Silurien plut&#xF4;t qu'au D&#xE9;vonien, et elle n'est done pas acadienne au sens strict; (4) l'activiti ign&#xE9;e tardisilurienne &#xE0; &#xE9;od&#xE9;vonienne survint dans un r&#xE9;gime tectonique de compression plut&#xF4;t que d'extension. [Traduit par le journal

    Great Mining Camps of Canada 7. The Bathurst Mining Camp, New Brunswick, Part 1: Geology and Exploration History

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    The Bathurst Mining Camp of northern New Brunswick is approximately 3800 km2 in area, encompassed by a circle of radius 35 km. It is known worldwide for its volcanogenic massive sulphide deposits, especially for the Brunswick No. 12 Mine, which was in production from 1964 to 2013. The camp was born in October of 1952, with the discovery of the Brunswick No. 6 deposit, and this sparked a staking rush with more hectares claimed in the province than at any time since.&nbsp;&nbsp; In 1952, little was known about the geology of the Bathurst Mining Camp or the depositional settings of its mineral deposits, because access was poor and the area was largely forest covered. We have learned a lot since that time. The camp was glaciated during the last ice age and various ice-flow directions are reflected on the physiographic map of the area. Despite abundant glacial deposits, we now know that the camp comprises several groups of Ordovician predominantly volcanic rocks, belonging to the Dunnage Zone, which overlie older sedimentary rocks belonging to the Gander Zone. The volcanic rocks formed during rifting of a submarine volcanic arc on the continental margin of Ganderia, ultimately leading to the formation of a Sea of Japan-style basin that is referred to as the Tetagouche-Exploits back-arc basin. The massive sulphide deposits are mostly associated with early-stage, felsic volcanic rocks and formed during the Middle Ordovician upon or near the sea floor by precipitation from metalliferous fluids escaping from submarine hot springs.&nbsp;&nbsp; The history of mineral exploration in the Bathurst Mining Camp can be divided into six periods: a) pre-1952, b) 1952-1958, c) 1959-1973, d) 1974-1988, and e) 1989-2000, over which time 45 massive sulphide deposits were discovered. Prior to 1952, only one deposit was known, but the efforts of three men, Patrick (Paddy) W. Meahan, Dr. William J. Wright, and Dr. Graham S. MacKenzie, focused attention on the mineral potential of northern New Brunswick, which led to the discovery of the Brunswick No. 6 deposit in October 1952. In the 1950s, 29 deposits were discovered, largely resulting from the application of airborne surveys, followed by ground geophysical methods. From 1959 to 1973, six deposits were discovered, mostly satellite bodies to known deposits. From 1974 to 1988, five deposits were found, largely because of the application of new low-cost analytical and geophysical techniques. From 1989 to 2000, four more deposits were discovered; three were deep drilling targets but one was at surface. RÉSUMÉLe camp minier de Bathurst, dans le nord du Nouveau-Brunswick, s’étend sur environ 3 800 km2 Ă  l’intĂ©rieur d’un cercle de 35 km de rayon. Il est connu dans le monde entier pour ses gisements de sulfures massifs volcanogĂšnes, en particulier pour la mine Brunswick n° 12, exploitĂ©e de 1964 Ă  2013. Le camp est nĂ© en octobre 1952 avec la dĂ©couverte du gisement Brunswick n° 6 et a suscitĂ© une ruĂ©e au jalonnement sans prĂ©cĂ©dent avec le plus d’hectares revendiquĂ©s dans la province qu’à prĂ©sent.&nbsp;&nbsp; En 1952, on savait peu de choses sur la gĂ©ologie du camp minier de Bathurst ou sur les conditions de dĂ©position de ses gisements minĂ©raux, car l’accĂšs Ă©tait trĂšs limitĂ© et la zone Ă©tait en grande partie recouverte de forĂȘt. Nous avons beaucoup appris depuis cette pĂ©riode. Le camp Ă©tait recouvert de glace au cours de la derniĂšre pĂ©riode glaciaire et diverses directions d’écoulements glaciaires sont rĂ©vĂ©lĂ©es sur la carte physiographique de la rĂ©gion. MalgrĂ© des dĂ©pĂŽts glaciaires abondants, nous savons maintenant que le camp comprend plusieurs groupes de roches ordoviciennes Ă  prĂ©dominance volcanique, appartenant Ă  la zone Dunnage, qui recouvrent de plus vieilles roches sĂ©dimentaires de la zone Gander. Les roches volcaniques se sont formĂ©es lors du rifting d’un arc volcanique sous-marin sur la marge continentale de Ganderia, ce qui a finalement abouti Ă  la formation d’un bassin de type mer du Japon, appelĂ© bassin d’arriĂšre-arc de Tetagouche-Exploits. Les gisements de sulfures massifs sont principalement associĂ©s aux roches volcaniques felsiques de stade prĂ©coce et se sont formĂ©s au cours de l’Ordovicien moyen sur ou proche du plancher ocĂ©anique par la prĂ©cipitation de fluides mĂ©tallifĂšres s’échappant de sources chaudes sous-marines.&nbsp;&nbsp; L’histoire de l’exploration miniĂšre dans le camp minier de Bathurst peut ĂȘtre divisĂ©e en six pĂ©riodes: a) antĂ©rieure Ă  1952, b) 1952-1958, c) 1959-1973, d) 1974-1988 et e) 1989-2000, au cours desquelles 45 dĂ©pĂŽts de sulfures massifs ont Ă©tĂ© dĂ©couverts. Avant 1952, un seul dĂ©pĂŽt Ă©tait connu, mais les efforts de trois hommes, Patrick (Paddy) W. Meahan, William J. Wright et Graham S. MacKenzie, ont attirĂ© l’attention sur le potentiel minier du nord du Nouveau-Brunswick, ce qui a conduit Ă  la dĂ©couverte du gisement Brunswick n° 6 au mois d’octobre 1952. Dans les annĂ©es 50, 29 gisements ont Ă©tĂ© dĂ©couverts, rĂ©sultant en grande partie de l’utilisation de levĂ©s aĂ©roportĂ©s, suivis de campagnes gĂ©ophysiques terrestres. De 1959 Ă  1973, six gisements ont Ă©tĂ© dĂ©couverts. Ce sont essentiellement des formations satellites de gisements connus. De 1974 Ă  1988, cinq gisements ont Ă©tĂ© dĂ©couverts, principalement grĂące Ă  l’utilisation de nouvelles techniques analytiques et gĂ©ophysiques peu coĂ»teuses. De 1989 Ă  2000, quatre autres gisements ont Ă©tĂ© dĂ©couverts. Trois Ă©taient des cibles de forage profondes, mais l’un Ă©tait Ă  la surface

    Great Mining Camps of Canada 8. The Bathurst Mining Camp, New Brunswick, Part 2: Mining History and Contributions to Society

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    In the Bathurst Mining Camp (BMC), 12 of the 45 known massive sulphide deposits were mined between 1957 and 2013; one was mined for iron prior to 1950, whereas three others had development work but no production. Eleven of the deposits were mined for base metals for a total production of approximately 179 Mt, with an average grade of 3.12% Pb, 7.91% Zn, 0.47% Cu, and 93.9 g/t Ag. The other deposit was solely mined for gold, present in gossan above massive sulphide, producing approximately one million tonnes grading 1.79 g/t Au. Three of the 11 mined base-metal deposits also had a gossan cap, from which gold was extracted. In 2012, the value of production from the Bathurst Mining Camp exceeded 670millionandaccountedfor58percentoftotalmineralproductioninNewBrunswick.Base−metalproductionstartedintheBMCin1957fromdepositsatHeathSteeleMines,followedbyWedgein1962,BrunswickNo.12in1964,BrunswickNo.6in1965,Caribouin1970,MurrayBrook,StratmatBoundaryandStratmatN−5in1989,CaptainNorthExtensionin1990,andlastly,HalfMileLakein2012.TheonlymineincontinuousproductionformostofthistimewasBrunswickNo.12.Duringits49−yearlifetime(1964–2013),itproduced136,643,367tonnesoforegrading3.44670 million and accounted for 58 percent of total mineral production in New Brunswick.Base-metal production started in the BMC in 1957 from deposits at Heath Steele Mines, followed by Wedge in 1962, Brunswick No. 12 in 1964, Brunswick No. 6 in 1965, Caribou in 1970, Murray Brook, Stratmat Boundary and Stratmat N-5 in 1989, Captain North Extension in 1990, and lastly, Half Mile Lake in 2012. The only mine in continuous production for most of this time was Brunswick No. 12. During its 49-year lifetime (1964–2013), it produced 136,643,367 tonnes of ore grading 3.44% Pb, 8.74% Zn, 0.37% Cu, and 102.2 g/t Ag, making it one of the largest underground base-metal mines in the world.The BMC remains important to New Brunswick and Canada because of its contributions to economic development, environmental measures, infrastructure, mining innovations, and society in general. The economic value of metals recovered from Brunswick No. 12 alone, in today’s prices exceeds 46 billion. Adding to this figure is production from the other mines in the BMC, along with money injected into the local economy from annual exploration expenditures (100s of 1000speryear)over60years.SeveralenvironmentalmeasureswereinitiatedintheBMC,includingtherequirementtobecleanshavenandcarryaportablerespirator(nowappliedtoallminesinCanada);waystotreatacidminedrainageandthethiosaltproblemthatcomesfromthemillingprocess;andpioneeringstudiestodevelopandinstallstreamside−incubationboxesforAtlanticSalmoneggsintheNepisiguitRiver,whichboostedsurvivalratestoover901000s per year) over 60 years. Several environmental measures were initiated in the BMC, including the requirement to be clean shaven and carry a portable respirator (now applied to all mines in Canada); ways to treat acid mine drainage and the thiosalt problem that comes from the milling process; and pioneering studies to develop and install streamside-incubation boxes for Atlantic Salmon eggs in the Nepisiguit River, which boosted survival rates to over 90%. Regarding infrastructure, provincial highways 180 and 430 would not exist if not for the discovery of the BMC; nor would the lead smelter and deep-water port at Belledune. Mining innovations are too numerous to list in this summary, so the reader is referred to the main text. Regarding social effects, the new opportunities, new wealth, and training provided by the mineral industry dramatically changed the living standards and social fabric of northern New Brunswick. What had been a largely poor, rural society, mostly dependent upon the fishing and forestry industries, became a thriving modern community. Also, untold numbers of engineers, geologists, miners, and prospectors `cut their teeth’ in the BMC, and many of them have gone on to make their mark in other parts of Canada and the world.Dans le camp minier de Bathurst (CMB), 12 des 45 gisements de sulfures massifs connus ont Ă©tĂ© exploitĂ©s entre 1957 et 2013; un de ces gisements a Ă©tĂ© exploitĂ© pour le fer avant 1950, tandis que trois autres Ă©taient en dĂ©veloppement mais pas en production. Onze gisements ont Ă©tĂ© exploitĂ©s pour des mĂ©taux communs pour une production totale d'environ 179 Mt, avec une teneur moyenne de 3,12% Pb, 7,91% Zn, 0,47% Cu et 93,9 g/t Ag. L'autre gisement Ă©tait uniquement exploitĂ© pour l'or, prĂ©sent dans le gossan au-dessus du sulfure massif, produisant environ un million de tonnes titrant 1,79 g/t Au. Trois des 11 gisements de mĂ©taux communs exploitĂ©s avaient Ă©galement un gossan, d'oĂč l'or Ă©tait extrait. En 2012, la valeur de la production du camp minier de Bathurst dĂ©passait 670 millions de dollars et reprĂ©sentait 58% de la production minĂ©rale totale au Nouveau-Brunswick.La production de mĂ©taux communs a commencĂ© dans le CMB en 1957 Ă  partir des gisements de Heath Steele Mines, suivie de Wedge en 1962, Brunswick no 12 en 1964, Brunswick no 6 en 1965, Caribou en 1970, Murray Brook, Stratmat Boundary et Stratmat N- 5 en 1989, Captain North Extension en 1990, et enfin Half Mile Lake en 2012. La seule mine en production continue pendant la majeure partie de cette pĂ©riode Ă©tait Brunswick no 12. Au cours de sa durĂ©e de vie de 49 ans (1964–2013), elle a produit 136 643 367 tonnes de minerai titrant 3,44% Pb, 8,74% Zn, 0,37% Cu et 102,2 g/t Ag, ce qui en fait l'une des plus grandes mines souterraines de mĂ©taux communs au monde.Le CMB demeure important pour le Nouveau-Brunswick et le Canada en raison de sa contribution au dĂ©veloppement Ă©conomique, aux mesures environnementales, Ă  l'infrastructure, aux innovations miniĂšres et Ă  la sociĂ©tĂ© en gĂ©nĂ©ral. La valeur Ă©conomique des mĂ©taux rĂ©cupĂ©rĂ©s du seul gisement Brunswick n° 12, aux prix d’aujourd’hui, dĂ©passe 46 milliards de dollars. S'ajoute Ă  ce chiffre la production des autres mines du CMB, ainsi que l'argent injectĂ© dans l'Ă©conomie locale par les dĂ©penses d'exploration annuelles (des centaines Ă  des milliers de par an) sur 60 ans. Plusieurs mesures environnementales ont Ă©tĂ© lancĂ©es dans le CMB, y compris l'exigence d'ĂȘtre rasĂ© de prĂšs et de porter un respirateur portatif (maintenant appliquĂ© Ă  toutes les mines au Canada); les moyens de traitement des effluents miniers acides et le problĂšme des thiosels qui proviennent du processus de broyage; et les Ă©tudes pionniĂšres pour dĂ©velopper et installer des boĂźtes d'incubation en bord de riviĂšre pour les Ɠufs de saumon de l'Atlantique dans la riviĂšre Nepisiguit, ce qui a fait passer les taux de survie Ă  plus de 90%. En ce qui concerne les infrastructures, les routes provinciales 180 et 430 n'existeraient pas sans la dĂ©couverte du CMB; la fonderie de plomb et le port en eau profonde de Belledune non plus. Les innovations miniĂšres sont trop nombreuses pour ĂȘtre Ă©numĂ©rĂ©es dans ce rĂ©sumĂ©, le lecteur est donc renvoyĂ© au texte principal. En ce qui concerne les effets sociaux, les nouvelles possibilitĂ©s, la nouvelle richesse et la formation offertes par l'industrie miniĂšre ont radicalement changĂ© le niveau de vie et le tissu social du nord du Nouveau-Brunswick. Ce qui avait Ă©tĂ© une sociĂ©tĂ© rurale en grande partie pauvre, principalement tributaire des industries de la pĂȘche et de la sylviculture, est devenu une communautĂ© moderne florissante. De plus, un nombre incalculable d’ingĂ©nieurs, de gĂ©ologues, de mineurs et de prospecteurs «se sont fait les dents» au CMB, et bon nombre d’entre eux ont continuĂ© Ă  faire leurs marques dans d’autres rĂ©gions du Canada et du monde
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