Academic literature on the topic 'Shawinigan (Canada)'

The Central Metasedimentary Belt boundary zone (CMBbz) is a crustal-scale shear zone that juxtaposes the Central Gneiss Belt and the Central Metasedimentary Belt of the Grenville Province. Geochronological work on the timing of deformation and metamorphism in the CMBbz is ambiguous, and the questions that motivate our study are: how many episodes of shear zone activity did the CMBbz experience, and what is the tectonic significance of each episode? We present electron microprobe data from monazite (the U–Th–Pb chemical method) to directly date deformation and metamorphism recorded in five garnet–biotite gneiss samples collected from three localities of the CMBbz of Ontario (West Guilford, Fishtail Lake, and Killaloe). All three localities yield youngest monazite dates ca. 1045 Ma; most of the monazite domains that yield these dates are high-Y rims. In comparison with this common late Ottawan history, the earlier history of the three CMBbz localities is less clearly shared. The West Guilford samples have monazite grain cores that show older high-Y domains and younger low-Y domains; these cores yield a prograde early Ottawan (1100–1075 Ma) history. The Killaloe samples yield a well-defined prograde, pre- to early Shawinigan history (i.e., 1220–1160 Ma) in addition to some evidence for a second early Ottawan event. In other words, the answers to our research questions are: three events; a Shawinigan event possibly associated with crustal thickening, an Ottawan event possibly associated with another round of crustal thickening, and a late Ottawan event that resists simple interpretation in terms of metamorphic history but that coincides chronologically with crustal thinning at the base of an orogenic lid.

The Holarctic genus Agonochaetia is reviewed and a new species, Agonochaetia shawinigan Landry, sp. nov. is described from Québec, Canada. In addition, a new glandiductor-bearing genus and species, Canarischema fuerteventura Karsholt, gen. nov., sp. nov. is described from the Canary Islands. Comparative diagnoses, a key to species, illustrations of external aspect, male and female genitalia are provided for all species. Most species of Agonochaetia are rarely collected and known only from their types or from very few specimens. DNA barcodes are provided for four of the species from which DNA was recovered. Analysis of DNA barcodes suggests that Agonochaetia may be paraphyletic. Phylogenetic relationships to other Gnorimoschemini genera bearing a pair of glandiductors above the phallus are discussed.

The Parker phlogopite mine, located near Notre-Dame-du-Laus, Quebec, 74 km north of Ottawa, is well known among mineral collectors for its centimetric euhedral crystals of black spinel. Among the dozens of phlogopite mines active in the early 1900s in the Mont-Laurier–Bancroft corridor in the Central Metasedimentary Belt of the Grenville Province, the Parker mine is exceptional because of the association of forsterite + spinel with phlogopite. Euhedral crystals of these minerals are found “frozen” in a carbonate matrix. The carbonate dike and segregations are associated with spinel-rich dunite that contains accessory diopside, phlogopite, and pargasite, as well as ilmenite and apatite. The interstitial melt crystallized to calcite + dolomite. Hematite appeared as flakes in the melt owing to net loss of hydrogen, and the spinel underwent oxidation-induced exsolution. Our spinel crystal entrapped a domain of carbonate during growth. It also entrapped globules of boundary-layer melt that crystallized to a carbonate + sulfate + phosphate + silicate + oxide assemblage. Such globules, where present in the cumulate, are more pristine than in the coarse crystal of spinel, i.e., less affected by a hydrothermal overprint. We contend that the carbonate melt ultimately formed by the hydrous melting of marble, as supported by oxygen-isotope data on all major minerals. Melting occurred 1140 million years ago, at a time of tectonic relaxation following the Shawinigan compressive stresses.

La mise en place d'équipes autonomes se traduit, du fait de l'abolition de la fonction de chef de poste, par un accroissement des interdépendances au niveau des opérateurs de production. Ces nouvelles interdépendances sont à l'origine de régulations et normes sociales spécifiques à l'échelle des équipes. Ce processus se traduit par une tendance forte à la différenciation des équipes autonomes. Les observations dans deux usines d'aluminium montrent cependant que le niveau de différenciation des équipes demeure très inégal selon les différents ateliers et que ces différences peuvent être reliées à la cohérence de l'environnement organisationnel des équipes au sein des différents secteurs de production. L'environnement des équipes forme un espace d'autonomie et l'articulation des trois dimensions de cet espace - le changement organisationnel, l'organisation de la hiérarchie et le système de relations professionnelles - est révélatrice de sa cohérence. L'espace d'autonomie influence directement le comportement de groupe des équipes autonomes et la cohérence de cet espace devient source d'autorité et de pouvoir. L'articulation entre les équipes et leur environnement constitue la face cachée de l'autonomie, qui trop souvent reste focalisée, dans la conception des managers et consultants, sur les seules équipes de travail.