The Rouyn-Noranda area in the center of the Abitibi subprovince is composed of comparatively unmetamorphosed Archean volcanics of Blake River Group (ERG). Rouyn-Nornada is one of the lozenge shaped structural blocks in the area bounded by the Porcupine Destor Fault (PDF) zone and the Larder Lake Caddilac Fault (LCF) zone. 160 samples were collected from 29 different sites selected to lie in the center of the block, at or near the PDF zone and accross the PDF zone in the neighboring lozenge. Stable magnetizations have been obtained from the central relatively unstrained parts of the lozenges. These magnetizations show some improvement in precision statistics after structural corrections implying that they are pre-folding and probably Archean in age. Sites along the PDF zone show scattered magnetizations, which do not agree at sample or site level. The Zone I (Sites in the center of the Rouyn-Noranda block) structurally corrected mean direction (D=154.0, I=-95.0, k=19.0, a95 =19.0, N=6 sites) differ from the Zone III (Sites from the center of the adjacent block) mean direction (D=214.0, I=-49.0, k=16.0, a95 =92.0) by 60+/-37° implying that the Rouyn-Norand block have rotated anti-clockwise by 60+/-37° about a vertical axis relative to the adjacent structural block. / Thesis / Master of Science (MS)

L’exploitation minière détériore les écosystèmes par la génération de contaminants qui affectent la diversité fonctionnelle des processus bactériens. Le mémoire suivant avait pour but de caractériser l’impact d’un gradient polymétallique sur la diversité et la structure taxonomique de communautés bactériennes lacustres d’un système de lacs dans la région de Rouyn-Noranda. Deux méthodes furent utilisées pour décrire la dynamique de la diversité et de la structure taxonomique des communautés bactériennes à partir du gène codant l’ARNr 16S : l’électrophorèse sur gel en gradient dénaturant et le séquençage de nouvelle génération 454. Les résultats ont démontré i) que l’exposition à des métaux lourds induit des changements dans la diversité et la structure taxonomique des communautés bactériennes et ii) qu’une pression de sélection similaire provoque un phénomène d’évolution parallèle chez des communautés bactériennes indépendantes. Cette étude aura ainsi permis d’apporter de nouvelles connaissances en ce qui a trait aux changements profonds que subissent les communautés bactériennes sous l’influence des métaux lourds et ce, autant d’un point de vue écologique qu’évolutif. / There are growing concerns about ecosystems being disturbed by mining activities which release heavy metals consequently exerting a strong selective pressure on the functional diversity of bacterial processes. Therefore, this thesis aimed to characterize the impact of diffuse polymetallic pollution over the taxonomic diversity and structure of lacustrine bacterial communities from sites located in the surroundings of Rouyn-Noranda. To this end, denaturing gradient gel electrophoresis and pyrosequencing of 16S rRNA sequences were used. The results showed that i) communities’ equilibrium was disturbed at both the diversity and structure levels and that ii) a similar selective pressure induced parallel evolution within independent bacterial communities. Our study therefore sheds light on the importance of analyzing bacterial communities at the taxonomic diversity and structure level to generate insights about the community changes taking places under polymetallic contaminants at both an ecological and evolutionary point of view.

The West Ansil deposit was the first Cu discovery in 25 years in the Noranda Central Camp. It has a combined indicated and inferred resource of ~1.2 Mt. Grades for the indicated resource are 3.4% Cu, 0.4% Zn, 1.4 g/t Au and 9.2 g/t Ag. The bulk of the resource is located in three massive sulphide lenses (Upper, Middle and Lower) that are entirely within the Rusty Ridge Formation above the Lewis exhalite. The mineralization in all three ore lenses consists of massive pyrrhotite + chalcopyrite + magnetite. Semi-massive sphalerite is restricted to the upper and lower parts of the Middle lens. Massive magnetite occurs at the center of the Upper and Middle lenses, where it replaces massive pyrrhotite. A striking feature of West Ansil is the presence of abundant colloform and nodular pyrite (+marcasite) in the massive sulphides. Late-stage replacement of massive pyrrhotite by colloform pyrite and marcasite, occurs mostly along the upper and lower contacts of the lenses.

The West Ansil deposit was the first Cu discovery in 25 years in the Noranda Central Camp. It has a combined indicated and inferred resource of ~1.2 Mt. Grades for the indicated resource are 3.4% Cu, 0.4% Zn, 1.4 g/t Au and 9.2 g/t Ag. The bulk of the resource is located in three massive sulphide lenses (Upper, Middle and Lower) that are entirely within the Rusty Ridge Formation above the Lewis exhalite. The mineralization in all three ore lenses consists of massive pyrrhotite + chalcopyrite + magnetite. Semi-massive sphalerite is restricted to the upper and lower parts of the Middle lens. Massive magnetite occurs at the center of the Upper and Middle lenses, where it replaces massive pyrrhotite. A striking feature of West Ansil is the presence of abundant colloform and nodular pyrite (+marcasite) in the massive sulphides. Late-stage replacement of massive pyrrhotite by colloform pyrite and marcasite, occurs mostly along the upper and lower contacts of the lenses.

The West Ansil deposit was the first Cu discovery in 25 years in the Noranda Central Camp. It has a combined indicated and inferred resource of ~1.2 Mt. Grades for the indicated resource are 3.4% Cu, 0.4% Zn, 1.4 g/t Au and 9.2 g/t Ag. The bulk of the resource is located in three massive sulphide lenses (Upper, Middle and Lower) that are entirely within the Rusty Ridge Formation above the Lewis exhalite. The mineralization in all three ore lenses consists of massive pyrrhotite + chalcopyrite + magnetite. Semi-massive sphalerite is restricted to the upper and lower parts of the Middle lens. Massive magnetite occurs at the center of the Upper and Middle lenses, where it replaces massive pyrrhotite. A striking feature of West Ansil is the presence of abundant colloform and nodular pyrite (+marcasite) in the massive sulphides. Late-stage replacement of massive pyrrhotite by colloform pyrite and marcasite, occurs mostly along the upper and lower contacts of the lenses.

The West Ansil deposit was the first Cu discovery in 25 years in the Noranda Central Camp. It has a combined indicated and inferred resource of ~1.2 Mt. Grades for the indicated resource are 3.4% Cu, 0.4% Zn, 1.4 g/t Au and 9.2 g/t Ag. The bulk of the resource is located in three massive sulphide lenses (Upper, Middle and Lower) that are entirely within the Rusty Ridge Formation above the Lewis exhalite. The mineralization in all three ore lenses consists of massive pyrrhotite + chalcopyrite + magnetite. Semi-massive sphalerite is restricted to the upper and lower parts of the Middle lens. Massive magnetite occurs at the center of the Upper and Middle lenses, where it replaces massive pyrrhotite. A striking feature of West Ansil is the presence of abundant colloform and nodular pyrite (+marcasite) in the massive sulphides. Late-stage replacement of massive pyrrhotite by colloform pyrite and marcasite, occurs mostly along the upper and lower contacts of the lenses.

Massive sulfide deposits in the Noranda mining camp, northwestern Québec, are mainly associated with extensive footwall alteration defined by intense chloritization and sericitization. However, Fe-carbonate alteration also occurs in proximity to some deposits. To test the exploration significance of carbonate alteration in the camp, two areas of intense carbonate alteration were examined, around the small Delbridge deposit and near the new Pinkos occurrence in the Cyprus Rhyolite. Between 1969 and 1971, the Delbridge deposit produced 370,000 t of ore grading 9.6% Zn, 0.61% Cu, 110 g/t Ag, and 2.1 g/t Au. Recent drilling at the new Pinkos occurrence intersected 2.64 m of massive to semi-massive sulfides grading 8.1% Zn and 18.2 g/t Ag. Alteration mapping has shown that the distribution of Fe-carbonates can be used to identify vertically extensive zones of hydrothermal upflow at both properties. At Delbridge, intense Fe-carbonate alteration in brecciated rhyolite defines a pipe-like upflow zone that extends vertically for up to 300 m within the stratigraphic footwall of the massive sulfides and 100 m into the hanging wall. The location of known massive sulfide mineralization coincides with the intersection of the alteration pipe and a favorable horizon marked by the occurrence of fine-grained volcaniclastic rocks. At Pinkos, a similar zone of Fe-carbonate alteration occurs in outcrops of coherent rhyolite. Fe-carbonate alteration is most intensely developed along polygonal cooling fractures in massive rhyolite and decreases in intensity towards the centers of the columns. Fe-carbonate stringers and locally abundant matrix carbonate occur in fragmental rocks at the stratigraphic top of the coherent rhyolite flows and are most intense at the location of sulfide-bearing outcrops that mark the known mineralized horizon. Whereas Fe-carbonate alteration defines the central part of the hydrothermal upflow zones at both properties, disseminated pyrite occurs at the margins and is widespread outside the main upflow zones. This may indicate that Fe-carbonate in the main upflow zones formed at the expense of earlier disseminated sulfides. Replacement of pyrite by synvolcanic Fe-carbonate alteration at Delbridge and Pinkos can probably be attributed to a relatively high concentration of dissolved CO2, possibly of magmatic origin, in the main-stage ore-forming fluids.

Massive sulfide deposits in the Noranda mining camp, northwestern Québec, are mainly associated with extensive footwall alteration defined by intense chloritization and sericitization. However, Fe-carbonate alteration also occurs in proximity to some deposits. To test the exploration significance of carbonate alteration in the camp, two areas of intense carbonate alteration were examined, around the small Delbridge deposit and near the new Pinkos occurrence in the Cyprus Rhyolite. Between 1969 and 1971, the Delbridge deposit produced 370,000 t of ore grading 9.6% Zn, 0.61% Cu, 110 g/t Ag, and 2.1 g/t Au. Recent drilling at the new Pinkos occurrence intersected 2.64 m of massive to semi-massive sulfides grading 8.1% Zn and 18.2 g/t Ag. Alteration mapping has shown that the distribution of Fe-carbonates can be used to identify vertically extensive zones of hydrothermal upflow at both properties. At Delbridge, intense Fe-carbonate alteration in brecciated rhyolite defines a pipe-like upflow zone that extends vertically for up to 300 m within the stratigraphic footwall of the massive sulfides and 100 m into the hanging wall. The location of known massive sulfide mineralization coincides with the intersection of the alteration pipe and a favorable horizon marked by the occurrence of fine-grained volcaniclastic rocks. At Pinkos, a similar zone of Fe-carbonate alteration occurs in outcrops of coherent rhyolite. Fe-carbonate alteration is most intensely developed along polygonal cooling fractures in massive rhyolite and decreases in intensity towards the centers of the columns. Fe-carbonate stringers and locally abundant matrix carbonate occur in fragmental rocks at the stratigraphic top of the coherent rhyolite flows and are most intense at the location of sulfide-bearing outcrops that mark the known mineralized horizon. Whereas Fe-carbonate alteration defines the central part of the hydrothermal upflow zones at both properties, disseminated pyrite occurs at the margins and is widespread outside the main upflow zones. This may indicate that Fe-carbonate in the main upflow zones formed at the expense of earlier disseminated sulfides. Replacement of pyrite by synvolcanic Fe-carbonate alteration at Delbridge and Pinkos can probably be attributed to a relatively high concentration of dissolved CO2, possibly of magmatic origin, in the main-stage ore-forming fluids.

Massive sulfide deposits in the Noranda mining camp, northwestern Québec, are mainly associated with extensive footwall alteration defined by intense chloritization and sericitization. However, Fe-carbonate alteration also occurs in proximity to some deposits. To test the exploration significance of carbonate alteration in the camp, two areas of intense carbonate alteration were examined, around the small Delbridge deposit and near the new Pinkos occurrence in the Cyprus Rhyolite. Between 1969 and 1971, the Delbridge deposit produced 370,000 t of ore grading 9.6% Zn, 0.61% Cu, 110 g/t Ag, and 2.1 g/t Au. Recent drilling at the new Pinkos occurrence intersected 2.64 m of massive to semi-massive sulfides grading 8.1% Zn and 18.2 g/t Ag. Alteration mapping has shown that the distribution of Fe-carbonates can be used to identify vertically extensive zones of hydrothermal upflow at both properties. At Delbridge, intense Fe-carbonate alteration in brecciated rhyolite defines a pipe-like upflow zone that extends vertically for up to 300 m within the stratigraphic footwall of the massive sulfides and 100 m into the hanging wall. The location of known massive sulfide mineralization coincides with the intersection of the alteration pipe and a favorable horizon marked by the occurrence of fine-grained volcaniclastic rocks. At Pinkos, a similar zone of Fe-carbonate alteration occurs in outcrops of coherent rhyolite. Fe-carbonate alteration is most intensely developed along polygonal cooling fractures in massive rhyolite and decreases in intensity towards the centers of the columns. Fe-carbonate stringers and locally abundant matrix carbonate occur in fragmental rocks at the stratigraphic top of the coherent rhyolite flows and are most intense at the location of sulfide-bearing outcrops that mark the known mineralized horizon. Whereas Fe-carbonate alteration defines the central part of the hydrothermal upflow zones at both properties, disseminated pyrite occurs at the margins and is widespread outside the main upflow zones. This may indicate that Fe-carbonate in the main upflow zones formed at the expense of earlier disseminated sulfides. Replacement of pyrite by synvolcanic Fe-carbonate alteration at Delbridge and Pinkos can probably be attributed to a relatively high concentration of dissolved CO2, possibly of magmatic origin, in the main-stage ore-forming fluids.

Entre 2018 et 2020, la réalisation et la publication de deux recherches s'intéressant à la quantification de certains contaminants présents sous les ongles d'enfants puis d'adultes de la ville de Rouyn-Noranda au Québec secoua la population locale. On constata des taux absurdes d'arsenic, de plomb et de cadmium sur le bout des doigts de citoyens et citoyennes, bien au-delà des taux maximums recommandés. Malgré ce constat, l'entreprise responsable de la propagation de ces polluants, la fonderie Horne de Glencore, poursuivit ses activités à plein régime et célébra ses 95 ans auprès de sa communauté. Une mobilisation citoyenne impressionnante s'observa par l'organisation de manifestations, l'écriture de mémoires ou la publication de lettres ouvertes dans les journaux. Un plan de réduction des émissions d'arsenic fut adopté par le gouvernement provincial en mars 2023, visant certes une diminution des rejets d'arsenic, sans se soumettre toutefois à la norme québécoise en vigueur. La destruction du quartier longeant la fonderie est à venir, ainsi que la relocalisation de 80 ménages. Cette étude qualitative explore les représentations sociales des citoyens et citoyennes de Rouyn-Noranda à l'égard de l'industrie emblématique ainsi que des acteurs impliqués. À travers l'utilisation d'entretiens semi-dirigés, les perceptions, croyances et émotions de quinze résidents et résidentes furent recueillies. Les résultats dévoilent une diversité de points de vue reflétant des degrés variables d'inquiétude concernant les risques environnementaux et sur la santé associés à la Horne, ainsi que des opinions divergentes de l'impact de cette installation sur l'économie locale. Les citoyens expriment également ressentir de la négligence et de l'indifférence de la part de l'État, contribuant ainsi à un désengagement progressif d'une partie de la population devant l'enjeu. Cette étude souligne le manque de ressources disponibles pour les personnes subissant des torts de la part d'une industrie, que l'on nommera ici *victimes environnementales industrielles*, afin de faire cesser la situation de compromission et d'obtenir réparation.