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The 1125-m-thick type section of the Pennsylvanian Boss Point Formation is well exposed along the shore of the Bay of Fundy in Nova Scotia. We provide the first comprehensive account of the entirety of this formation, which comprises nearly one-third of the stratigraphic thickness of the Joggins Fossil Cliffs UNESCO World Heritage Site. The basal Chignecto Bay Member (0-91.5 m) is composed of redbeds, single-storey channel bodies with northerly paleoflow, and thin palustrine limestones. The middle Ward Point Member (91.5-951.7 m) contains up to 16 megacycles composed of alternations between thick packages of braided fluvial sandstone and fine-grained deposits. Although regional studies of the Boss Point Formation suggest that the fine-grained deposits are largely composed of lacustrine sediments, these intervals consist largely of poorly drained and well-drained floodplain deposits in the type section. The facies variations and southeast-directed paleoflow in the Ward Point Member record modest uplift associated with the growth of the salt-cored Minudie Anticline. The North Reef Member (951.7-1125 m) is composed of redbeds and two distinctive multistorey channel bodies. This uppermost member records a shift to more arid, oxidizing conditions, was the precursor to a major phase of salt withdrawal, and represents a transition to the overlying Little River Formation. The sedimentological framework, revised stratigraphy, and detailed measured section and map will provide a foundation for future study of this remarkable Pennsylvanian exposure. Le stratotype de 1 125 metres depaisseur de la formation de Boss Point du Pennsylvanien est bien expose sur la rive de la baie de Fundy, en Nouvelle-Ecosse. Nous presentons le premier compte rendu complet de cette formation dans son integralite, qui comprend pres du tiers de lepaisseur stratigraphique des falaises fossiliferes de Joggins, reconnues site du patrimoine mondial de l'UNESCO. Le membre basal de la baie Chignectou (de 0 m a 91,5 m) se compose de couches rouges, de corps de chenaux monostratifies au paleo-ecoulement vers le nord et de minces couches de calcaire palustre. Le membre moyen de Ward Point (de 91,5 m a 951,7 m) renferme jusqua 16 megacycles composes en alternance depaisses masses de gres fluvial anastomose et de depots a grains fins. Meme si des etudes sur la region de la formation de Boss Point donnent a penser que les depots a grains fins sont surtout composes de sediments lacustres, ces intervalles sont constitues en grande partie de depots alluviaux mal draines et bien draines dans le stratotype. Les variations dans le facies et le paleo-ecoulement en direction du sud-est dans le membre de Ward Point temoignent d'un soulevement modeste associe a la croissance de l'anticlinal de Minudie a noyau salifere. Le membre de North Reef (de 951,7 m a 1 125 m) se compose de couches rouges et de deux corps de chenaux multistratifies distinctifs. Ce membre superieur atteste d'une transition vers des conditions oxydantes, plus arides, il a ete le precurseur d'une importante phase de retrait du sel et il represente une transition vers la formation susjacente de Little River. Le cadre sedimentologique, la stratigraphie revisee ainsi que la coupe et la carte detaillees mesurees serviront de fondement a une prochaine etude sur ce remarquable affleurement de la periode pennsylvanienne. [Traduitpar la redaction], INTRODUCTION The 1125-m-thick type section of the Boss Point Formation comprises approximately one third of the stratigraphic thickness of the Joggins Fossil Cliffs UNESCO World Heritage Site. It is of [...]

The invasion of the land was a complex, protracted process, punctuated by mass extinctions, that involved multiple routes from marine environments. We integrate paleobiology, ichnology, sedimentology, and geomorphology to reconstruct Paleozoic terrestrialization. Cambrian landscapes were dominated by laterally mobile rivers with unstable banks in the absence of significant vegetation. Temporary incursions by arthropods and worm-like organisms into coastal environments apparently did not result in establishment of continental communities. Contemporaneous lacustrine faunas may have been inhibited by limited nutrient delivery and high sediment loads. The Ordovician appearance of early land plants triggered a shift in the primary locus of the global clay mineral factory, increasing the amount of mudrock on the continents. The Silurian–Devonian rise of vascular land plants, including the first forests and extensive root systems, was instrumental in further retaining fine sediment on alluvial plains. These innovations led to increased architectural complexity of braided and meandering rivers. Landscape changes were synchronous with establishment of freshwater and terrestrial arthropod faunas in overbank areas, abandoned fluvial channels, lake margins, ephemeral lakes, and inland deserts. Silurian–Devonian lakes experienced improved nutrient availability, due to increased phosphate weathering and terrestrial humic matter. All these changes favoured frequent invasions to permament establishment of jawless and jawed fishes in freshwater habitats and the subsequent tetrapod colonization of the land. The Carboniferous saw rapid diversification of tetrapods, mostly linked to aquatic reproduction, and land plants, including gymnosperms. Deeper root systems promoted further riverbank stabilization, contributing to the rise of anabranching rivers and braided systems with vegetated islands. New lineages of aquatic insects developed and expanded novel feeding modes, including herbivory. Late Paleozoic soils commonly contain pervasive root and millipede traces. Lacustrine animal communities diversified, accompanied by increased food-web complexity and improved food delivery which may have favored permanent colonization of offshore and deep-water lake environments. These trends continued in the Permian, but progressive aridification favored formation of hypersaline lakes, which were stressful for colonization. The Capitanian and end-Permian extinctions affected lacustrine and fluvial biotas, particularly the invertebrate infauna, although burrowing may have allowed some tetrapods to survive associated global warming and increased aridification. [ABSTRACT FROM AUTHOR]

The Early Devonian Campbellton Formation in northern New Brunswick, Canada, yielded its first eurypterid fossils in 1881. Based on recent taxonomic work, all known specimens have been assigned to Pterygotus [...]

Strata of the Campbellton Formation, nearly 1 km-thick and known for its diverse fossil assemblage of early plants, arthropods, and fish, can be divided into six facies associations: (1) restricted lacustrine, (2) marginal lacustrine, (3) near-shore lacustrine, (4) coastal-deltaic, (5) sandy to gravelly alluvial plain, and (6) gravelly proximal alluvial environments. Lacustrine deposits with restricted circulation, due to depth or stagnation, are fine-grained with preserved organic material. The marginal lacustrine association consists of massive siltstone and very fine sandstone, interbedded with conglomerate. The latter are interpreted to have shed from older volcanic units forming the basin walls. The near-shore lacustrine association is characterized by rippled sandstone with microbialites. Alluvial strata include interbedded imbricate to nonimbricate conglomerate, trough cross-stratified sandstone, and barren to plant-bearing siltstone. Rare exposures of thickly bedded imbricate to weakly imbricated cobble-boulder conglomerate with sandy plant-bearing lenses are interpreted as products of hyperconcentrated debris flows. In the western belt, a braided-fluvial system had paleocurrents flowing WNW. Coastal-deltaic deposits west of the fluvial outcrops, containing aquatic vertebrates and invertebrates, had paleocurrents flowing ESE, suggesting a confined body of fresh or brackish water. In lower parts of the eastern belt, lacustrine facies are prevalent, representing a large open lake. Alluvial facies dominate upper parts of the formation, representing an eastward-flowing axial braided river system, with proximal alluvium shed transversely from the basin margins. Although most strata have a volcanic provenance, only one outcrop in the lacustrine beds shows evidence of active volcanism during deposition of the Campbellton Formation. D'une epaisseur d'environ 1 km, les strates de la Formation de Campbellton sont connues pour ses assemblages diversifies de fossiles d'anciennes plantes, d'arthropodes et de poissons; elles peuvent etre divisees en six associations de facies : (1) lacustre restreinte, (2) lacustre de bordure, (3) lacustre pres d'un rivage, (4) cotier-deltaique, (5) plaine alluviale de sable a gravier et (6) environnements proximaux de gravier alluvionnaire. En raison de la profondeur ou de stagnation, les depots lacustres avec circulation reduite sont a grain fin et contiennent de la matiere organique preservee. L'association lacustre de bordure comprend des siltstones massifs et des gres tres fins, interlites avec des conglomerats. Ces derniers proviendraient d'anciennes unites volcaniques qui forment les parois du bassin. L'association pres du rivage est caracterisee par des gres rides contenant des microbialites. Les strates alluvionnaires comprennent un conglomerat imbrique a non imbrique, des gres de fosse a stratification croisee et des siltstones steriles a contenant des plantes. De rares affleurements de conglomerats imbriques a lits epais a des conglomerats de cailloux a blocs faiblement imbriques avec des lentilles sablonneuses comportant des plantes, sont interpretes en tant que produits de coulees de debris hyperconcentrees. Dans la ceinture ouest, un systeme de ruisseaux anastomoses avait des paleocourants qui s'ecoulaient vers l'ONO. Les depots cotiers-deltaiques a l'ouest des affleurements fluviaux, contenant des vertebres et des invertebres aquatiques, avaient des paleocourants qui s'ecoulaient vers l'ESE, suggerant un plan confine d'eau douce ou saumatre. Dans les parties inferieures de la ceinture orientale, les facies lacustres prevalent, representant un vaste lac ouvert. Des facies alluviaux dominent les parties superieures de la formation, representant un systeme axial de rivieres anastomosees coulant vers l'est, avec des alluvions proximales qui tombent transversalement aux bordures du bassin. Bien que la plupart des strates proviennent de volcans, un affleurement dans les lits lacustres montre des evidences de volcanisme actif pendant la deposition de la Formation de Campbellton. [Traduit par la Redaction], Introduction On the southern shore of the Restigouche River in New Brunswick, Canada, near the head of Chaleur Bay, a narrow belt of the Emsian to Eifelian Campbellton Formation is [...]

A long-standing hypothesis links the increased prominence of meandering rivers in the middle Paleozoic to the colonization of terrestrial environments by vegetation. This hypothesis is tested using a data set of Cambrian to Devonian fluvial literature and field examination of key stratigraphic units. According to some researchers, Cambrian to mid-Silurian river systems were braided in planform, with a sharp increase in the abundance of meandering rivers during the Silurian--Devonian. Although meandering systems were largely identified on the basis of thick mudstones and organized channel deposits, the data set record of lateral accretion sets appears to be a robust proxy for the abundance of meandering river point bars. Lateral accretion is first recorded from Pridolian--Lochkovian strata, but is noted in nearly 40% of fluvial case studies by the Famennian. This trend matches the known record of rooted vegetation, suggesting that vegetation progressively stabilized river banks and promoted single-thread channels. However, the presence of Precambrian and extraterrestrial meandering systems indicates that vegetation is not essential for meandering, and the lack of evidence for Cambrian to Silurian (Ludlow) point bars is surprising. If originally present, they may largely have been destroyed by extreme floods, chute cut-offs in coarse-grained meandering systems, and eolian activity. doi: 10.1130/G30443

ABSTRACT Joggins, Nova Scotia, was one of the first places in North America where coal was mined. Dendrochronological methods were employed to date timber pit props preserved within relic coal [...]

Abstract: The Lower Cretaceous Chaswood Formation is a terrestrial deposit preserved as scattered outcrops across Maritime Canada. Here we describe newly recognized outliers of the Chaswood Formation near Windsor, Nova [...]

Cyclothems are documented for the first time in alluvial to coastal plain strata (Westphalian D to Stephanian) of the Sydney Basin, Nova Scotia. Well-developed cyclothems commence with an extensive carbonaceous limestone or shale with a restricted marine biota that indicates maximal flooding. Succeeding gray detrital bay and lake fills with distributary channel deposits are overlain by stacked channel deposits (paleovalley fills) that mark an abrupt basinward facies shift and a profound change in alluvial style. Channel fills and red vertisols were deposited on an alluvial plain above the filled valleys, and the paleovalley is equated with thick vertisols in adjacent, interfluve areas. The cyclothems are capped by gray coastal deposits with economic coals. Agglutinated foraminifera are present in seat earths beneath the coals, which formed as a result of a brief stillstand during transgression. Red mudstones pass laterally into gray detrital bay fills in regions of greater subsidence associated with faulted basement blocks. Poorly developed cyclothems are bounded by extensive but split coals, and autogenic effects partially obscure allogenic patterns. Mean cyclothem duration approximates 200 ka.