77 research outputs found

    Climate–vegetation models bring fossil forests back to life

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    Earliest history of coal mining and grindstone quarrying at Joggins, Nova Scotia, and its implications for the meaning of the place name “Joggins”

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    The rich history of coal mining and grindstone quarrying at Joggins, Nova Scotia, prior to Lyell’s visit in 1842 is less well known than its subsequent history. Franquelin first observed coal there in 1686, and within little more than a decade Acadian coal mines had sprung up at the Coal Cliffs. Following the British acquisition of Nova Scotia in 1713, the coal mines attracted Captain Belcher and other New England traders, who loaded their ships with coal for sale in Boston. In 1731, eager to impose duty on this unregulated trade, the Nova Scotia Council sponsored a British coal mine at Joggins operated by Major Cope. Unable to safely load ships at the Coal Cliffs, Cope constructed a wharf and coal depot at Gran’choggin (present-day Downing Cove), seven miles to the north of the mine. It was by association with this depot that the Coal Cliffs later became known as Joggins. Cope’s coal mine survived less than eighteen months before the Mi’kmaq, aided and abetted by Acadians, destroyed the site in 1732. Following this episode, Acadians worked the Joggins coal mines until they fell under the control of British forces engaged in the Seven Years War in 1756. Subsequently, the Lords of Trade suppressed coal mining at Joggins, fearing it would harm British imports, and full-scale operations did not recommence until 1847. During this lull, the grindstone industry boomed. Beginning sometime before 1764, the principal stone quarries operated at Lower Cove, where the famous Blue-Grit was cut. Grindstone quarries were also worked on the Maringouin Peninsula and the two opposing sides of Chignecto Bay became known as the North and South Joggins. RÉSUMÉ On connaĂźt moins bien le riche passĂ© de l’extraction du charbon et de la pierre meuliĂšre Ă  Joggins, Nouvelle‑Écosse, avant la visite de Lyell en 1842, que son passĂ© subsĂ©quent. Franquelin y avait observĂ© du charbon pour la premiĂšre fois en 1686 et en l’espace d’un peu plus d’une dĂ©cennie, plusieurs mines de charbon acadiennes Ă©taient apparues Ă  Coal Cliffs. À la suite de l’acquisition de la Nouvelle‑Écosse par les Britanniques en 1713, les mines de charbon ont attirĂ© le capitaine Belcher et d’autres commerçants de la Nouvelle‑Angleterre qui chargeaient leurs vaisseaux de charbon pour le vendre Ă  Boston. En 1731, impatient d’imposer des droits sur ce commerce non rĂ©glementĂ©, le Conseil de la Nouvelle‑Écosse a parrainĂ© l’exploitation Ă  Joggins d’une mine de charbon britannique exploitĂ©e par le major Cope. Incapable de charger de façon sĂ©curitaire les navires Ă  Coal Cliffs, Cope construisit un quai et un dĂ©pĂŽt de charbon Ă  Gran’choggin (anse Downing actuelle), Ă  sept milles au nord de la mine. L’association Ă  ce dĂ©pĂŽt a plus tard confĂ©rĂ© Ă  Coal Cliffs le nom de Joggins. La mine de charbon de Cope a subsistĂ© moins de 18 mois jusqu’à ce que les Micmacs, aidĂ©s et soutenus par les Acadiens, dĂ©truisirent l’emplacement en 1732. AprĂšs cet Ă©pisode, les Acadiens ont exploitĂ© les mines de charbon de Joggins jusqu’à ce qu’elles tombent sous le contrĂŽle des forces britanniques engagĂ©es dans la guerre de Sept Ans en 1756. Les lords du commerce ont subsĂ©quemment supprimĂ© l’extraction du charbon Ă  Joggins, par crainte qu’elle fasse tort aux importations britanniques, et l’exploitation Ă  grande Ă©chelle n’a pas recommencĂ© avant 1847. Pendant cette pĂ©riode d’accalmie, l’industrie de la pierre meuliĂšre a connu un essor notable. Les principales carriĂšres de pierre ont commencĂ© leurs activitĂ©s dans les annĂ©es ayant prĂ©cĂ©dĂ© 1764 Ă  Lower Cove, oĂč l’on extrayait le fameux grĂšs dur bleu. Des carriĂšres de pierre meule ont Ă©galement Ă©tĂ© exploitĂ©es sur la pĂ©ninsule Maringouin et les deux rives opposĂ©es de la baie Chignectou devinrent connues sous les noms de North et South Joggins

    Anatomically-preserved cordaitalean trees from Lower Pennsylvanian (Langsettian) dryland alluvial-plain deposits at Joggins, Nova Scotia

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    Recent discoveries at Joggins, Nova Scotia have altered our understanding of the Pennsylvanian tropical biome. Of particular signiïŹcance has been the recognition of seasonal dryland ecosystems, compositionally distinct from the peat-forming wetland rainforests. Here I describe two anatomically-preserved fossil plant specimens from dryland alluvial plain facies. The ïŹrst specimen, Mesoxylon cf. sutclifïŹ i, is previously unknown from Joggins. It is a septate cordaitalean axis with mesarch leaf traces and a non-sympodial vasculature. Where found as isolated blocks, the secondary xylem of this plant has previously been classiïŹed as Dadoxylon recentium. The axis exhibits subtle growth interruptions suggestive of tropical rainfall seasonality, while associated traumatic zones may record ïŹre-damage. The second specimen is a Dadoxylon stump rooted within well-drained ïŹ‚oodbasin soils. It conïŹrms earlier conjecture, based on parautochthonous assemblages, that cordaitalean trees grew in inter-channel areas. Together these new specimens improve our knowledge of the composition and ecology of seasonal dryland vegetation at Joggins. RÉSUMÉ Des dĂ©couvertes rĂ©centes Ă  Joggins (Nouvelle-Écosse), ont modiïŹĂ© notre comprĂ©hension du biome tropical pennsylvanien. La reconnaissance d'Ă©cosystĂšmes de milieux arides saisonniers aux compositions distinctes des forĂȘts tropicales humides ayant formĂ© des tourbiĂšres, s'avĂšre particuliĂšrement importante. Je dĂ©cris aux prĂ©sentes deux spĂ©cimens prĂ©servĂ©s de plantes fossiles anatomiquement provenant du faciĂšs d'une plaine alluviale de milieu aride. Le premier spĂ©cimen, un Mesoxylon cf. sutclifïŹ i, Ă©tait auparavant inconnu Ă  Joggins. Il s'agit d'un axe cordaitalĂ©en cloisonnĂ© comportant des cicatrices foliaires Ă  arc moyen et une vasculature non sympodiale. Lors de sa dĂ©couverte sous forme de blocs isolĂ©s, on avait prĂ©cĂ©demment classiïŹĂ© le xylĂšme secondaire de cette plante en tant que Dadoxylon recentium L'axe prĂ©sente des interruptions de croissance subtiles Ă©voquant des chutes de pluie tropicales saisonniĂšres, tandis que les cernes traumatiques associĂ©s pourraient tĂ©moigner de dommages causĂ©s par le feu. Le second spĂ©cimen est une souche de Dadoxylon qui plongeait ses racines Ă  l'intĂ©rieur des sols d'un bassin de crue bien drainĂ©. Il conïŹrme une conjecture antĂ©rieure, basĂ©e sur des assemblages parautochtones, supposant que les arbres cordaitalĂ©ens aient poussĂ© dans des secteurs situĂ©s entre des chenaux. Ces deux nouveaux spĂ©cimens amĂ©liorent notre connaissance de la composition et de l'Ă©cologie de la vĂ©gĂ©tation saisonniĂšre des milieux arides Ă  Joggins. [Traduit par la rĂ©daction.

    A Cordaixylon axis from well-drained alluvial plain facies in the Lower Pennsylvanian Joggins Formation of Nova Scotia

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    Plant remains showing preservation of cellular anatomy are rare in the Lower Pennsylvanian Joggins Formation of Nova Scotia. Here I report an anatomically preserved cordaitalean axis that shows endarch maturation and a sympodial vascular architecture. The specimen belongs to the morphogenus Cordaixylon, but in the absence of extraxylary tissue or attached fertile material, it cannot be assigned to a species. Together with a previously reported Mesoxylon axis with mesarch and non-sympodial vasculature, the new discovery demonstrates the existence of both major organizational types of cordaitalean at this locality. Previous reports have identified Cordaixylon as a plant that preferred peat mire environments. In this paper, the morphogenus is recorded from well-drained alluvial plain facies, thus extending knowledge of its ecological range. RĂ©sumĂ© Les vestiges de plantes prĂ©sentant une prĂ©servation de l’anatomie cellulaire sont rares Ă  l’intĂ©rieur de la Formation du Pennsylvanien infĂ©rieur de Joggins, en Nouvelle-Écosse. Je fais part dans les prĂ©sentes d’un axe de cordaitalĂ©en natomiquement prĂ©servĂ© qui affiche une maturation circulaire Ă  partir de l’intĂ©rieur et une architecture vasculaire sympodiale. Le spĂ©cimen fait partie du morphogenre Cordaixylon, mais en l’absence de tissu extraxylaire ou de matiĂšre fertile y Ă©tant fixĂ©e, on ne peut pas le rattacher Ă  une espĂšce donnĂ©e. La nouvelle dĂ©couverte, conjuguĂ©e Ă  un axe de Mesoxylon prĂ©cĂ©demment signalĂ© qui comportait une vasculature non sympodiale Ă  Ă©lĂ©ments en spirale internes, rĂ©vĂšle l’existence des deux principaux types structuraux de cordaitalĂ©ens Ă  cet emplacement. Des rapports antĂ©rieurs avaient dĂ©fini le Cordaixylon en tant que plante prĂ©fĂ©rant les environnements Ă  bourbiers de tourbe. Le prĂ©sent document fait Ă©tat de l’observation du morphogenre d’un faciĂšs de plaine alluviale bien drainĂ©e, ce qui Ă©tend notre connaissance de son aire de distribution Ă©cologique

    The oldest Pinus and its preservation by fire

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    Sir William Dawson (1820–1899): a very modern paleobotanist

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    Sir William Dawson was one of Canada’s most influential Nineteenth Century geologists. Although a lifelong opponent of the concept of evolution, a stance that resulted in him being sidelined by the scientific community, he made enormous contributions to Pennsylvanian paleobotany, especially at the Joggins fossil cliffs of Nova Scotia. Key to Dawson’s success was his recognition of the importance of a field-based research program, in which fossil plants could be observed in their precise geological context over a sustained period of time. Uniquely trained as both geologist and botanist, he was skilled in the microscopic analysis of permineralized plant anatomy, and appreciated the enormous potential of fossil charcoal as an untapped source of systematic information. Arguably his most extraordinary insights came in the field of plant taphonomy, in which studies of modern sedimentary processes and environments were used to interpret the rock record. His analysis of fossil plants in their sedimentary context allowed Pennsylvanian coal swamp communities, dominated by lycopsids and calamiteans, to be distinguished from the coniferopsid forests, which occupied mountainous regions further inland. The lasting significance of Dawson’s paleobotanical work is emphasized by many recent papers concerning the Pennsylvanian coal measures of Atlantic Canada, which have either directly built on research topics that Dawson initiated, or have confirmed hypotheses that Dawson framed. Until recent times, the discipline of paleobotany has been dominated by systematic fossil plant description with little or no reference to geological context. By virtue of his distinctively holistic approach, synthesizing all available geological and botanical data, Dawson is marked out from his contemporaries. His methodology does not appear old-fashioned even today, and it is therefore with justification that we describe him as a very modern paleobotanist. ResumĂ© Sir William Dawson a Ă©tĂ© l’un des gĂ©ologues les plus influents du 19e siĂšcle au Canada. MĂȘme s’il s’est opposĂ© toute sa vie au concept de l’évolution, une position qui a amenĂ© le milieu scientifique Ă  l’ignorer, il a Ă©normĂ©ment contribuĂ© Ă  la palĂ©obotanique pennsylvanienne, spĂ©cialement dans les falaises fossilifĂšres de Joggins de la Nouvelle-Écosse. La clĂ© du succĂšs de Dawson rĂ©side dans le fait qu’il avait reconnu l’importance d’un programme de recherche sur le terrain prĂ©voyant l’observation des plantes fossiles dans leur milieu gĂ©ologique particulier pendant une pĂ©riode de temps prolongĂ©e. GrĂące Ă  sa formation unique de gĂ©ologue et de botaniste, il possĂ©dait la compĂ©tence voulue pour rĂ©aliser une analyse microscopique de l’anatomie des plantes perminĂ©ralisĂ©es et il comprenait le potentiel Ă©norme du charbon de bois fossile comme source inexploitĂ©e de donnĂ©es systĂ©matiques. On pourrait soutenir que ses idĂ©es les plus extraordinaires se sont manifestĂ©es dans le domaine de la taphonomie vĂ©gĂ©tale, dans lequel des Ă©tudes d’environnements et de processus sĂ©dimentaires modernes ont servi Ă  interprĂ©ter des antĂ©cĂ©dents lithologiques. Ses analyses de plantes fossiles dans leur contexte sĂ©dimentaire ont permis de distinguer les communautĂ©s des marĂ©cages houillers pennsylvaniens, dans lesquels prĂ©dominent les lycopsides et les calamites, des forĂȘts conifĂ©ropsides, qui occupaient les rĂ©gions montagneuses plus Ă  l’intĂ©rieur des terres. De nombreuses communications rĂ©centes au sujet des couches houillĂšres pennsylvaniennes des provinces de l’Atlantique, qui s’appuient directement sur des sujets de recherches amorcĂ©es par Dawson ou ayant confirmĂ© des hypothĂšses formulĂ©es par Dawson, mettent en relief l’importance durable des travaux palĂ©obotaniques de Dawson. La discipline de la palĂ©obotanique a jusqu’à tout rĂ©cemment Ă©tĂ© dominĂ©e par des descriptions systĂ©matiques de plantes fossiles Ă©voquant Ă  peine ou n’évoquant pas du tout le contexte gĂ©ologique. Dawson s’est dĂ©marquĂ© de ses contemporains au moyen de son approche nettement holistique en rĂ©alisant une synthĂšse de toutes les donnĂ©es gĂ©ologiques et botaniques accessibles. Sa mĂ©thode de travail ne semble pas rĂ©trograde, mĂȘme aujourd’hui, et il est par consĂ©quent tout Ă  fait justifiĂ© que nous le dĂ©crivions en tant que palĂ©obotaniste trĂšs moderne
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