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Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper concerns the petrogenesis of the 504 ± 3 Ma Mont Chagnon massif, the southern extension of the Orford ophiolite in the Quebec Appalachians. The evolution of this massif is summarized in three stages marked by different magmatic series. In the Late Cambrian, the onset of southeastern subduction of the Iapetus basin generated an immature oceanic island arc made up of light rare-earth-element-depleted tholeiites, now preserved in the massif as a portion of the intrusive crustal unit, the dyke complex, and part of the lower volcanic unit. A phase of arc splitting, and concomitant partial erosion of the crustal section, was shortly followed by the eruption of rhyolite genetically related to felsic and low-Ti dykes, and trondhjemite. The geochemistry of these magmas bear some similarities with boninitic series. We believe these liquids derived from the partial melting of the Iapetus amphibolitized oceanic crust, with that of its Laurentian-derived sediments and nearby peridotite, either found as a trapped sliver above the subducting slab or as the slab itself. The final stage, preserved in the massif as a part of the intrusive section, the upper volcanic rocks, and the late-stage dykes, represents the back-arc opening. An ocean-island component is involved in the back-arc related petrogenetic processes, producing magmas with compositions intermediate between arc tholeiites and enriched back-arc basin basalts. This is the first report that the Iapetus basin was locally closing as early as Late Cambrian in the southern Quebec area.Cet article traite de la pétrogenèse du massif du mont Chagnon, daté à 504 ± 3 Ma, qui est l'extension méridionale de l'ophiolite d'Orford dans les Appalaches du Québec. L'évolution de ce massif est résumée en trois étapes déterminées par des suites magmatiques différentes. Au Cambrien tardif, le début de la subduction vers le sud-est d'Iapetus a crée un arc insulaire océanique immature composé de tholéiites appauvries en terres rares légères, maintenant préservées dans le massif en tant qu'une portion de l'unité crustale intrusive, le complexe de dykes et une partie de l'unité volcanique inférieure. Une phase de division de l'arc, et l'érosion partielle concomitante de la section de la croûte, a été suivie de près par l'éruption de rhyolite, génétiquement reliée aux dykes felsiques et à ceux faibles en Ti, de même qu'à la trondhjémite. La géochimie de ces magmas comporte des similitudes avec les séries boninitiques. Nous croyons que ces liquides proviennent de la fusion partielle de la croûte amphibolitisée d'Iapetus, de ses sédiments dérivés du craton Laurentia et de la péridotite avoisinante, qui se trouvent soit coincés en tant qu'écaille au-dessus de la lithosphère en subduction ou soit en tant que lithosphère subductée elle-même. L'étape finale, préservée dans le massif en tant qu'une partie de la section intrusive, les roches volcaniques supérieures et les dykes tardifs, représente l'ouverture de l'arrière-arc. Une composante d'île océanique est impliquée dans les processus pétrogénétiques reliés à l'arrière-arc, produisant des magmas dont les compositions sont intermédiaires entre les tholéiites d'arc et les basaltes enrichis de bassins d'arrière-arc. Ceci est le premier rapport qu'Iapetus se refermait localement aussi tôt que le Cambrien tardif dans le sud du Québec.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

The Kamouraska Formation is a quartz-arenitic unit of latest Cambrian - earliest Ordovician age in the Quebec Appalachians that was deposited by hyperconcentrated to concentrated density flows in a meandering submarine canyon on the continental slope bordering the Iapetus Ocean, as outlined in a companion paper. Detailed petrographic study of the quartz arenites of the Kamouraska Formation combined with scanning electron microscopy of grain surface textures suggests that the quartz sands are of eolian origin having been derived from an inland desert or, less likely, a barrier beach dune system. Transport of the mature quartz-arenitic sand onto the shelf and deposition into the deep sea was not accompanied by substantial mixing with material from other sources thus preserving the inherited eolian characteristics. A modern analogue for the eolian interpretation of the deep-sea quartz-arenite beds is as follows: thick, Late Pleistocene eolian sand beds on a modern abyssal plain in the East Atlantic referred to as eolian-sand turbidites that were deposited in the deep sea during glacial sea level lowstands when eolian sand transport to canyon heads was enabled by an exposed and shortened shelf. Similarly, an established sea level lowstand at the Cambro-Ordovician boundary would have facilitated the introduction of eolian sand of the Kamouraska Foundation into canyon heads on the upper slope from where turbidity currents and related density flows were triggered. Correlation of the Kamouraska Formation with the quartz arenites of the Cairnside Formation of Quebec (Keeseville Formation in northern New York State, Nepean Formation in southern Ontario) links the deep-sea deposits with remnants of an inland dune system. [ABSTRACT FROM AUTHOR]

In the Archean Blake River Group, mafic to intermediate fragmental units have controversially been proposed to have formed during the collapse of a giant submarine caldera. This paper describes and interprets these rocks, summarizing their physical characteristics, inferred origins, age relationships, and geochemical signatures. The widespread Stadacona member, south of Rouyn-Noranda, consists of several hundred metres of bedded volcaniclastic rocks interpreted to have been mostly deposited from aqueous density currents fed directly by explosive eruptions. The magmas involved in these eruptions were plagioclase-phyric, tholeiitic to transitional basalts. The similarly widespread D'Alembert tuff, in the northern part of the Blake River Group, shares many physical characteristics with the Stadacona member and is thought to have a similar origin. However, the D'Alembert tuff is approximately six million years younger than the Stadacona member. It is composed mostly of transitional to calc-alkaline andesites and basaltic andesites with very distinct trace element profiles. Volcaniclastic rocks from other areas, such as Tannahill Township in Ontario and the Monsabrais area in Quebec, are interpreted to represent mostly in situ to remobilized hyaloclastite, with no explosive eruptions involved in their genesis. Our observations and interpretations are not compatible with models in which the volcaniclastic units are emplaced during a catastrophic event in relation with the collapse of a giant caldera. Instead, the fragmental rocks were produced by various mechanisms at many distinct times during the evolution of the Blake River Group. [ABSTRACT FROM AUTHOR]

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Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Paleoproterozoic southeastern Churchill Province (SECP) is located in the northeastern Canadian Shield of Labrador and Quebec. The SECP formed through the oblique collisions of the Archean Nain and Superior cratons with a third intervening Archean block, the core zone. The belt has a tripartite structure, comprising the Torngat Orogen (TO) formed by Nain craton – core zone collision in the east, the core zone in the centre, and the New Quebec Orogen (NQO) formed by Superior craton – core zone collision in the west. The SECP thus records transpressional development on the flanks of the Superior and Nain cratons as they indented northwards to form the larger Trans-Hudson – Nagssugtoqidian orogenic belt to the north. Principal stages of tectonic development were (1) 2.2–2.1 Ga crustal rifting of Nain and Superior cratons; (2) ca. 1.9 Ga subduction under eastern Nain craton; (3) ca. 1.87–1.85 Ga collision of Nain craton and core zone to form the TO; (4) 1.845–1.820 Ga sinistral transpression in the TO, and subduction under the western core zone; and (5) 1.82–1.77 Ga collision of Superior craton and core zone to form the NQO, in association with dextral transpression. Crustal-scale cross sections of the SECP have been developed from reflection and refraction seismic data. The western part of the NQO is dominantly west-vergent and associated with an imbricate thick-skinned thrust stack that ramps from the base of the crust. The core zone is characterized by a 35–40 km thick crust and pervasive east-dipping fabrics related to westerly thrusting. The TO is a narrow, doubly vergent belt, associated with a 48 km thick crust that forms a crustal root with a Moho relief of 12 km. The root is interpreted to result from attempted subduction of the core zone under the Nain craton, possibly as a result of mid-crustal wedging by the Nain craton. The TO was the site of intense convergence that resulted in excision of juvenile crust, possibly including tectonic removal of the axial magmatic arc. As a result, the middle to lower levels of the SECP consist largely of refractory Archean lithosphere. This may account for the lack of widespread post-collisional plutonism in the SECP and the preservation of the TO root.Le sud-est de la Province de Churchill (SECP, Southeastern Churchill Province; Paléoprotérozoïque) est situé dans le nord-est du Bouclier canadien, au Labrador et au Québec. Le SECP a été formé par des collisions obliques entre les cratons archéens de Nain et du Supérieur et un troisième bloc archéen intermédiaire, la zone noyau. La ceinture a une structure tripartite, comprenant l'orogène Torngat (TO), formé par la collision entre la zone noyau et le craton de Nain, à l'est, la zone noyau au centre et l'orogène du Nouveau-Québec (NQO), formé par la collision entre la zone noyau et le craton du Supérieur, à l'ouest. Le SECP enregistre donc le développement de transpressions sur les flancs des cratons de Nain et du Supérieur alors que ces derniers se déplaçaient vers le nord pour former la grande ceinture orogénique trans-hudsonienne – nagssugtoqidienne au nord. Les principaux stages de développement tectonique ont été : (1) la dérive crustale des cratons de Nain et du Supérieur, 2,2–2,1 Ga; (2) la subduction sous le craton de Nain oriental, vers 1,9 Ga; (3) la collision entre le craton de Nain et la zone noyau pour former l'orogène Torngat, vers 1,87–1,85 Ga; (4) la transpression senestre dans TO, 1,845–1,82 Ga; la subduction sous la zone noyau occidentale; (5) la collision entre le craton du Supérieur et la zone noyau pour former l'orogène du Nouveau-Québec, associée à de la transpression dextre, 1,82–1,77 Ga. Des coupes à l'échelle crustale du SECP ont été produites à partir de données de sismique réflexion et réfraction. La partie ouest de l'orogène du Nouveau-Québec est déversée surtout vers l'ouest et associée à une épaisse structure imbriquée de chevauchement qui remonte à partir de la base de la croûte. La zone noyau est caractérisée par une croûte dont l'épaisseur est de 35–40 km et des textures pénétrantes à pendage vers l'est qui sont reliées à du chevauchement vers l'ouest. L'orogène Torngat est une ceinture étroite à double vergence, associée à une croûte épaisse de 48 km qui forme une racine crustale avec un relief du Moho de 12 km. On interprète la racine comme une tentative de subduction de la zone noyau sous le craton de Nain, possiblement à la suite d'un coincement mi-crustal par le craton de Nain. L'orogène Torngat a été le site d'une intense convergence qui a eu comme résultat d'exciser la croûte juvénile, possiblement avec le retrait tectonique de l'arc magmatique axial. Il en a résulté que les niveaux mi-inférieurs du SECP consistent surtout de lithosphère archéenne réfractaire. Cela pourrait expliquer le manque de plutonisme post-collisionnel étendu dans le SECP et la préservation de la racine de l'orogène Torngat.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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We present new Sm–Nd isotope data for sediments from a core located on the continental slope of the St. Pierre Bank of Canada’s east coast. The Nd analyses indicate that the sediments were derived from two principal sources: the North American Shield that yields an average early Proterozoic isotopic signature and a younger Proterozoic signature attributed to Appalachian crustal sources. The Appalachian-sourced sediments predominated during the last glacial maximum (LGM) and were associated with low sedimentation rates (<30 cm/ka), with the exception of a strong North American Shield signature present in a detrital carbonate layer that corresponds to Heinrich Layer 1 (H1). The dominance of the Appalachian signature decreased subsequent to H1. The Appalachian signatures closely follow the distribution of sediments interpreted as locally derived glacial tills, while the North American Shield signatures follow the distribution of hemipelagic mud that was likely deposited by the Labrador Current. The Nd data are consistent with the persistence of the Wisconsinan Ice Sheet coverage of Newfoundland and the Grand Banks after the LGM, although the coverage began to wane prior to 12.5 ka as evidenced by the increasing influence of the Labrador Current. However, an increase in the Appalachian isotope signature at the close of the Younger Dryas event likely indicates the final melting of the ice sheet covering the Grand Banks and the Avalon Peninsula, and the initiation of the Labrador Current’s modern circulation pathway. Nous présentons de nouvelles données isotopiques Sm–Nd pour les sédiments provenant d’une carotte prélevée sur la pente continentale du Banc de Saint-Pierre de la Côte Est du Canada. Les analyses de Nd indiquent que les sédiments proviennent surtout de deux sources : le Bouclier nord-américain, lequel fournit une signature isotopique moyenne du Protérozoïque précoce et une signature Protérozoïque plus jeune attribuée aux sources de la croûte appalachienne. Les sédiments provenant de la source appalachienne prédominaient lors du dernier maximum glaciaire et ils sont associés à des taux de sédimentation faibles (< 30 cm/ka), à l’exception d’une forte signature du Bouclier nord-américain présente dans une couche de carbonate détritique qui correspond à l’événement Heinrich 1 (H1). La dominance de la signature appalachienne décroît après le H1. Les signatures appalachiennes suivent de près la distribution des sédiments, lesquels proviendraient de tills glaciaires, alors que les signatures du Bouclier nord-américain suivent la distribution d’une boue hémipélagique qui a fort probablement été déposée par le courant du Labrador. Les données Nd concordent avec la persistance de la couverture de la calotte glaciaire wisconsinienne de Terre-Neuve et des Grands Bancs après le dernier maximum glaciaire, bien que la couverture ait commencé à diminuer il y a plus de 12,5 ka, tel que mis en évidence par l’influence croissante du courant du Labrador. Toutefois, une augmentation de la signature isotopique appalachienne vers la fin de l’événement du Dryas Récent indique probablement la fonte finale de la calotte glaciaire qui recouvrait les Grands Bancs et la presqu'île Avalon et le début du tracé moderne de circulation du courant du Labrador. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)