Forty Years of Northern Non-Renewable Natural Resource Development

Northern Canada is endowed with abundant non-renewable natural resources, and exploration and development of those resources have increased steadily since World War II. Particularly during the past 20 years new regulatory controls have been emplaced in response to elevated concerns about the possible impact of resource development on the environment. During the past 40 years gold, silver, copper, lead, zinc, nickel, asbestos, tungsten, uranium, coal and other minor commodities have been produced from more than 30 mines in the northern mainland, but at the present time only 6 mines are producing gold, silver, lead and zinc in that area: Con, Giant Yellowknife, Echo Bay, Mount Skukum, United Keno Hill and Faro mines. Lead and zinc are being produced at the world's most northerly mine. Polaris, on Little Cornwallis Island, and lead, zinc and silver are mined at Nanisivik on Baffin Island. At least 375 oil and gas wells have been drilled north of the Arctic Circle in the northern mainland since 1947, and 42 oil and gas fields have been discovered in the Beaufort Sea-Mackenzie Delta area alone. Total discovered and undiscovered resources in the latter area approximate 2131 billion cu m gas and 1.35 billion cu m oil. From 1961, 176 wells were drilled in the Arctic Islands and 17 oil and gas fields were discovered. Discovered and undiscovered resources approximate 2257 billion cu m gas and 686 million cu m oil.Key words: minerals, oil, gas, coal, Beaufort Sea, Mackenzie Delta, Arctic Islands, weather stations, transportation Le nord du Canada a l'avantage de contenir des quantités abondantes de ressources naturelles non renouvelables, et la recherche ainsi que la mise en valeur de ces ressources ont augmenté continuellement depuis la Deuxième Guerre mondiale. Lors des dernières vingt années en particulier, de nouvelles réglementations de contrôle ont été mises en place pour répondre aux inquiétudes grandissantes concernant les retombées possibles de la mise en valeur des ressources naturelles sur l'environnement. Au cours des 40 dernières années, plus de 30 mines situées sur le continent nordique, ont produit de l'or, de l'argent, du cuivre, du plomb, du zinc, du nickel, de l'amiante, du tungstène, de l'uranium, du charbon et d'autres marchandises de moindre importance. À l'heure actuelle cependant, 6 mines seulement produisent de l'or, de l'argent, du plomb et du zinc dans cette région. Ce sont les mines de Con, Giant Yellowknife, Echo Bay, Mount Skukum, United Keno Hill et Faro. La mine Polaris, la plus septentrionale au monde, dans l'île Little Cornwallis, produit du plomb et du zinc, tandis que la mine de Nanisivik dans la Terre de Baffin produit du plomb, du zinc et de l'argent. Au moins 375 puits de gaz et de pétrole ont été forés au nord de cercle arctique sur le continent depuis 1847, et 42 champs pétroliers et gaziers ont été découverts dans la seule région de la mer de Beaufort et du delta du Mackenzie. Le total des ressources découvertes et non découvertes est proche de 2131 milliards de m³ de gaz et 1,35 milliards de m³ de pétrole. De 1961 à 1986, 175 puits ont été forés dans l'archipel Arctique, et 17 champs pétroliers et gaziers y ont été découverts. Les ressources découvertes et non découvertes y atteignent près de 2257 milliards de m³ de gaz et 686 millions de m³ de pétrole. Mots clés : minéraux, pétrole, gaz, charbon, mer de Beaufort, delta du Mackenzie, archipel Arctique, stations météorologiques, transpor

Was Phanerozoic reef history controlled by the distribution of non-enzymatically secreted reef carbonates (microbial carbonate and biologically induced cement)?

Throughout most of the Phanerozoic, reef rigidity resulted as much, or more, from early lithification by microbial carbonates and biologically induced cements (non-enzymatic carbonates) than from biological encrustation of, or by, large, enzymatically secreted metazoan skeletons. Reef framework is divided into four categories: (1) skeletal metazoan; (2) non-skeletal microbialite (stromatolite and thrombolite); (3) calcimicrobe; and (4) biocementstone, in which small or delicate organisms serve as scaffolds for rigid cement crusts. The last three categories are dominated by non-enzymatic carbonates. Skeletal framework and non-skeletal microbialite framework were the most abundant framework types through the Phanerozoic. The composition and abundance of skeletal framework was controlled largely by mass extinction events, but most reefs consisted of both microbialite and skeletal organisms in a mutually beneficial relationship. Microbialite framework was abundant throughout the Palaeozoic and early Mesozoic, but declined after the Jurassic. Calcimicrobe framework was important during the Cambrian-Early Ordovician and Devonian and biocementstone framework was important from the late Mississippian to the Late Triassic. The Phanerozoic history of reefs does not correlate well with the stratigraphic distribution of large, skeletal 'reef builders', or with a variety of physicochemical parameters, including sea-level history, Wilson Cycle or global climate cycles. Because non-enzymatic carbonates result from induction by non-obligate calcifiers, and not enzymatic precipitation by obligate calcifiers, the distribution of these carbonates was controlled to a larger extent by temporal changes in physicochemical parameters affecting the saturation state of sea water with respect to carbonate minerals. Changes in pCO, Ca/Mg ratios, cation concentrations and temperature may have affected the abundance of non-enzymatic carbonates and, hence, reefs, independently from the effects of these same parameters and mass extinction events on skeletal reef biota. The decline in abundance of reefal microbialite and absence of calcimicrobe and biocementstone reef framework after the Jurassic may be a result of relatively low saturation states of sea water owing to increased removal and sequestration of finite marine carbonate resources by calcareous plankton since the Jurassic. Reef history is difficult to correlate with temporal changes in specific global parameters because these parameters affect skeletal biota and biologically induced carbonate precipitation independently. Hence, reef history was regulated not just by skeletal reef biota, but by parameters governing non-enzymatic carbonates