Publications
Anticosti: Tourism, Industry, and Nature Construction on a Nordic, Peripheral Island
Anticosti Island's recognition as a UNESCO World Heritage Site in 2023 highlights the exceptional universal value of its nature and culture, particularly its nordicity and peripherality. This study reveals how these characteristics were reimagined by the tourism industry from locational impediments to attractions, making nature tourism an economic mainstay. The research draws on regional tourism histories to show that this transformation was achieved through a cultural construction process that complemented industry and urbanity. By analyzing Anticosti's unique position in the northern Gulf of St. Lawrence, the study provides insights into how peripheral locations can be leveraged for sustainable development.
Hirnantian (Late Ordovician) chemostratigraphy of Anticosti Island, eastern Canada: Comparison of stable carbon and oxygen isotope compositions from brachiopod shells and bulk carbonate
Brachiopod shells from Anticosti Island's Ellis Bay Formation preserve pristine stable carbon (C) and oxygen (O) isotope signatures, offering a more sensitive and faithful archive of ancient seawater composition than bulk carbonate. Intra-shell isotopic variations reveal consistent trends across ten species, with δ13C increasing by ~0.5–1‰ from early to late growth stages, indicating minimal diagenetic alteration. Inter-species comparisons show small differences in average δ13C and δ18O at given stratigraphic levels, supporting their comparability for chemostratigraphy. Notably, brachiopod shells exhibit significantly higher δ13C than bulk micrite during the peak Hirnantian Isotopic Carbon Excursion (HICE), reinforcing their utility as reliable proxies for paleoenvironmental reconstruction, particularly during the Hirnantian glaciation event.
Late Ordovician cornulitids from Anticosti Island, eastern Canada, and their evolutionary implications
Researchers have identified two new species of Late Ordovician cornulitids, Cornulites richmondensis and Cornulites hemistriatus, from Anticosti Island, Canada. These free-living organisms exhibit unique morphological traits, such as a thick, punctate, cross-bladed lamellar conch wall and septate juvenile parts, bridging the evolutionary gap between Cornulites and later Silurian-Devonian Tentaculites. The study suggests that these cornulitids share similarities with brachiopods in their shell microstructure but possess finer, less distinct lamellar layers. This discovery provides new insights into the evolutionary transition of these fossil groups during the Late Ordovician period.
Phylogenetic position and stratigraphic uncertainty of a new flexible crinoid from the Ordovician–Silurian boundary of Anticosti Island (Québec, Canada)
Researchers have identified a new flexible crinoid species, Anticosticrinus natiscotecensis, from the Ordovician–Silurian boundary of Anticosti Island (Québec, Canada), a region critical for studying the Late Ordovician mass extinction (LOME). Phylogenetic analysis places this species within the family Anisocrinidae, contributing to understanding crinoid faunal turnover during this pivotal period. The study also employed Bayesian methods to quantify stratigraphic age uncertainty, suggesting a late Hirnantian age, though not definitively resolving it. This discovery provides valuable data for evaluating extinction timing and diversification patterns in flexible crinoids, which became dominant in the Silurian.
A high-resolution sequence stratigraphic framework for the eastern Ellis Bay Formation, Canada: A record of Hirnantian sea-level change
A high-resolution sequence stratigraphic framework for the eastern Ellis Bay Formation on Anticosti Island, Canada, reveals six fourth-order depositional sequences bounded by subtle, regionally traceable unconformities. These sequences, marked by quartz pebble lags and depleted carbon isotopic values, provide a detailed record of Hirnantian sea-level changes during the Late Ordovician mass extinction. The framework enables the integration of paleobiological, stratigraphic, and geochemical data into a basin-wide perspective, suggesting that other coeval sections may be incomplete at the level of these fourth-order cycles.
Bridging the gap between Quebec and Newfoundland: new insights on the protracted and diachronic history of the Anticosti foreland basin
A new study reveals significant stratigraphic and tectonic variability along the Anticosti foreland basin, bridging Quebec and Newfoundland. The research identifies a thick post-Llandovery sedimentary succession (∼2 km) in two regional synclines, with youngest sediments correlating to the Upper Gaspé Sandstone Group–Red Island Road Formation (Emsian–Eifelian). Post-Eifelian deformation is characterized by folds ranging from 2–10 km in wavelength, with newly recognized northwest-striking faults exhibiting syn- to post-Middle Mississippian movements. The southern boundary of the basin is linked to an unconformity or poorly documented east-southeast to northeast-striking faults. Magnetic and seismic data were used to map rock units, distinguishing igneous dykes from sedimentary markers by their higher amplitude and geometry. This study enhances our understanding of the basin's complex history.
Chitinozoan biostratigraphy through the Aeronian–Telychian boundary interval on Anticosti Island, Canada
Researchers have refined the position of the Aeronian–Telychian boundary on Anticosti Island, Canada, using chitinozoan biostratigraphy. This study identifies two key biozones—the Ancyrochitina ramosaspina and Eisenackitina dolioliformis—which correlate with global standards, clarifying the timing of this critical interval in Earth's history. The findings also define three new chitinozoan species, providing precise markers for further geological studies. By integrating these data with existing conodont, graptolite, and brachiopod records, the study confirms limited unconformities at the boundary, contrasting with less complete coeval locations like the Baltic succession. This refined age model offers a solid foundation for investigating Llandovery biogeochemical events following the Late Ordovician mass extinction.
A new species ofHirnantia(Orthida, Brachiopoda) and its implications for the Hirnantian age of the Ellis Bay Formation, Anticosti Island, eastern Canada
Researchers have identified a new species of the brachiopod genus Hirnantia, H. notiskuani, from the lower Ellis Bay Formation on Anticosti Island, eastern Canada. This discovery, alongside the previously documented H. sagittifera in the uppermost Ellis Bay Formation, confirms that the entire formation spans the Hirnantian age, a critical period marking the Late Ordovician mass extinction. The study integrates brachiopod assemblages with palynological and chemostratigraphic data to refine the geological timeline of this UNESCO World Heritage Site. The findings highlight the unique diversity of the Hirnantia fauna in Anticosti, blending elements from both typical Hirnantian and Laurentian epeiric seas.
Genomic architecture of phenotypic extremes in a wild cervid
Research on Anticosti Island's white-tailed deer (Odocoileus virginianus) has uncovered significant genetic differences linked to extreme antler and body size traits, offering new insights for conservation efforts. By analyzing high-depth whole genome re-sequencing data from pools of individuals representing phenotypic extremes, scientists identified divergent genomic windows with mean allele frequency differences of 14% for antler and 13% for body size. Genes associated with antler morphology showed enrichment in pathways related to cell death, protein metabolism, and oncogenic processes, while body size traits exhibited a more complex genetic architecture. These findings highlight the potential of genomics in understanding evolutionary pressures and guiding management strategies for this UNESCO World Heritage Site.
The morphologic and paleobiogeographic implications of a new early Silurian echinoid from Anticosti Island, Quebec, Canada
Researchers have uncovered a new genus and species of early Silurian echinoid, Anticostiechinus petryki, from Anticosti Island, Quebec, Canada. This discovery sheds light on the initial diversification of sea urchins during the lower Paleozoic era. The morphology of A. petryki's tubercles and spines is atypical for echinoids, featuring rounded, concave indentations for spine articulation and subspherical spine bases. Belonging to the family Echinocystitidae, this find expands the known diversity and distribution of this family during the Silurian and Devonian periods, providing valuable insights into the paleobiogeography of echinocystitids.
Sulfidic anoxia in the oceans during the Late Ordovician mass extinctions – insights from molybdenum and uranium isotopic global redox proxies
A global oceanic sulfidic anoxia occurred during the Late Ordovician Mass Extinction (LOME2), significantly contributing to the 85% loss of marine animal species. This finding is supported by molybdenum and uranium isotopic proxies, with δ²³⁸U in carbonates from Anticosti Island serving as a key indicator. The study combines existing paleoredox data from four continents with new Mo isotope data, revealing that ocean anoxia was both spatially extensive and temporally linked to extinction phases. Additionally, periodic sulfidic anoxia in well-ventilated shallow oceans during warmer periods may have driven high seawater δ⁹⁸Mo values observed during LOME1. These insights suggest that oxygen loss played a causal role in both extinction phases.
Biomass Combined Heat and Power Generation for Anticosti Island: A Case Study
A biomass combined heat and power (CHP) plant could serve as a sustainable alternative to traditional electrical heating on Anticosti Island, Quebec. This study demonstrates the feasibility of such a system by designing, modeling, and simulating a CHP plant that leverages local biomass fuel to generate both electricity and district heating. The proposed design utilizes advanced steam turbine configurations—back-pressure or extraction turbines—to optimize heat recovery while maintaining efficient power generation. By integrating these technologies, the plant could meet Anticosti Island's energy demands with reduced reliance on fossil fuels, offering a scalable model for similar island communities in Canada.
Geothermal resource assessment of remote sedimentary basins with sparse data: lessons learned from Anticosti Island, Canada
A geothermal resource assessment of Anticosti Island, Canada, reveals significant potential for low-temperature geothermal electricity generation despite sparse and low-quality data. The study developed a 3D temperature model for the Ordovician/Silurian sedimentary basin and its underlying Precambrian basement, predicting temperatures up to 40 km depth with high variability (up to 70% at mantle depth) due to uncertain thermal parameters. While geothermal electricity generation from reservoirs at 120 °C or more is challenging in the current technical and economic context, low-temperature direct use of geothermal heat (inlet temperature of 70 °C) could be feasible at depths of 2–4 km, albeit with a net efficiency of 10–11%. The study highlights the need for improved thermal property data, particularly for the Precambrian basement and specific lithologies in the sedimentary basin, to enhance temperature prediction accuracy.
Absence of founder effect and evidence for adaptive divergence in a recently introduced insular population of white‐tailed deer (Odocoileus virginianus)
A recent study on Anticosti Island, Québec, Canada, reveals that the introduced white-tailed deer population has not experienced a strong founder effect despite originating from just 220 individuals over 120 years ago. This is attributed to rapid population growth, resulting in a current population exceeding 160,000 individuals with high genetic diversity. The research used genotyping-by-sequencing (GBS) to analyze 8,518 high-quality SNPs, showing weak but significant genetic differentiation between the insular and mainland populations. Notably, the study identified loci linked to muscular function and lipid metabolism, suggesting potential local adaptation to Anticosti's environmental conditions. These findings provide insights into the population dynamics and adaptive divergence of white-tailed deer in insular ecosystems.
Anticosti foreland basin offshore of western Newfoundland: Concealed record of northern Appalachian orogen development
The Anticosti foreland basin, largely concealed beneath the Gulf of St. Lawrence, preserves a critical record of tectonic events linked to the Ordovician to Devonian evolution of the northern Appalachian orogen. Geophysical data, including magnetic lineaments and seismic profiles, reveal that the basin's geometry and subsidence rates varied significantly over time, reflecting changes in orogenic loading during multiple collisional events. The Middle Ordovician Goose Tickle Group indicates intense arc-continent collision in northern Newfoundland, while the overlying Long Point Group suggests pro-arc loading by Taconian allochthons in Québec, with diachronous subduction polarity reversal placing it in a combined retro-arc and pro-arc setting. The uppermost Silurian to Lower Devonian Clam Bank Formation and Lower Devonian Red Island Road Formation represent later Salinian and Acadian orogenic phases, characterized by broad, shallow subsidence consistent with a cooler, stronger lithosphere.
New taxa and revised stratigraphic distribution of the crinoid fauna from Anticosti Island, Québec, Canada (Late Ordovician-early Silurian)
Research on Anticosti Island, Québec, Canada, has uncovered seven new crinoid species and revised the stratigraphic distribution of these marine organisms during the Late Ordovician to early Silurian period. This study confirms that Xenocrinus rubus crossed the Ordovician-Silurian boundary, while also extending the range of several other taxa. The findings provide critical insights into the macroevolutionary turnover following the End-Ordovician extinctions, which significantly impacted shallow-water benthic communities. Anticosti Island's well-preserved stratigraphic section offers a unique window to study these changes, with new taxa including Becsciecrinus groulxin, Jovacrinus clarkin, and others contributing to our understanding of crinoid evolution during this pivotal geological period.
Perforocycloides nathalieae new genus and species, an unusual Silurian cyclocystoid (Echinodermata) from Anticosti Island, Québec, Canada
Researchers have identified Perforocycloides nathalieae, a new genus and species of cyclocystoid, a rare and poorly understood class of echinoderms, from the early Silurian period on Anticosti Island in Québec, Canada. This discovery marks the first articulated cyclocystoid found in North America during this geological timeframe. The specimen is distinguished by its unique dorsal intermarginal sutural pores and canals, which suggest a novel communication system between the dorsal disc and ventral marginals/cupules. Comparative analysis indicates that Perforocycloides closely resembles Zygocycloides, hinting at greater Silurian diversity than previously thought. The study also highlights significant gaps in global knowledge of cyclocystoid distribution, particularly within Gondwana regions and Přidolí strata.
Sea level, carbonate mineralogy, and early diagenesis controlled δ13C records in Upper Ordovician carbonates
A global interval of elevated carbon isotope ratios (δ13C) during the Upper Ordovician, linked to glaciation, is not solely a record of global ocean chemistry but is influenced by sea-level changes and early marine diagenesis. Research on carbonate strata from Anticosti Island, Canada, and the Great Basin, USA, reveals that variations in δ44Ca and Sr/Ca ratios reflect primary aragonite mineralogy and diagenetic processes, which modulate δ13C records. Deep-ramp settings preserve elevated δ13C due to increased aragonitic preservation during sea-level lowstands, while mid- and inner ramp settings show muted shifts due to extensive early marine diagenesis under seawater-buffered conditions. This challenges the assumption that shallow-water carbonate proxies always reflect global ocean changes.
The trace fossil Sinusichnus from the Upper Ordovician of Anticosti Island, eastern Canada
A significant discovery of the trace fossil Sinusichnus cf. seilacheri in Upper Ordovician (Hirnantian) carbonates on Anticosti Island, eastern Canada, marks the oldest record of this ichnogenus, previously unknown before the Triassic and unreported from North America. These branched, sinusoidal burrows, found abundantly at the base of the Oncolite Bed in the Ellis Bay Formation, indicate a regional discontinuity surface during the multiphase Ordovician mass-extinction event. Unlike Mesozoic and Cenozoic records linked to decapod or isopod crustaceans, these burrows likely represent the activity of other arthropods with unknown affinity, suggesting a combined dwelling, locomotion, and feeding behavior. This finding extends the geological range of Sinusichnus by over 200 million years and provides new insights into Ordovician paleoecology.
Anticosti Island: a hot spot for Neospondylis upiformis (Coleoptera: Cerambycidae) in eastern Canada?
Anticosti Island emerges as a potential hot spot for the rare longhorned beetle, Neospondylis upiformis, in eastern Canada. Unprecedented numbers of this species were captured during an insect diversity inventory in 1993 and again in 2007, with over 90% of specimens originating from old-growth balsam fir stands in the island's south-central region. The study, conducted using ethanol- and α-pinene-baited Lindgren traps, revealed that adult flight activity peaks in early July, ranging from June to late July. In contrast, only 14 specimens were found across major Quebec insect collections, with the most recent dating back to 1964. This suggests Anticosti's unique ecological conditions may support a significant population of N. upiformis, warranting further conservation attention.
Provenance and depositional environment of organic-rich calcareous black shale of the Late Ordovician Macasty Formation, western Anticosti Basin, eastern Canada
Research on the Late Ordovician Macasty Formation in Anticosti, Canada, reveals that its organic-rich black shale was deposited under anoxic conditions during the Taconic orogeny. Neodymium isotope analysis indicates a predominantly Grenvillian provenance, with intense weathering of source rocks contributing to fine-grained detritus deposition. The study also highlights the enrichment of redox-sensitive elements (As, V, U) and high δ34S for pyrite, supporting anoxic conditions at the sediment-water interface. Calcite cement formation during low-temperature diagenesis (<60 °C) further explains the preservation of organic matter in this shale.
Range extension of the threatened Red Crossbill (Loxia curvirostra percna) in Canada: new insights from Anticosti Island, Québec
A significant range extension for the threatened Red Crossbill (Loxia curvirostra percna) has been identified on Anticosti Island, Québec, Canada. This discovery expands the known distribution of the subspecies, which was previously considered limited to the Gaspe Peninsula and the Charlevoix region. Researchers used a combination of field observations, acoustic monitoring, and genetic analysis to document the presence of Red Crossbills on Anticosti Island, confirming their breeding activity and providing insights into their ecological adaptability. The study highlights the importance of this newly identified population for conservation efforts, particularly in light of habitat changes and climate variability.
A revised correlation of Silurian rocks in the British Isles
A revised correlation of Silurian rocks in the British Isles establishes a detailed stratigraphical framework for Llandovery, Wenlock, Ludlow, and Přidolí successions across Wales, England, Scotland, and Ireland. The study provides correlation charts that integrate selected outcrops and concealed sequences, offering a robust regional standard. It extends this framework internationally by comparing British Silurian records with those from Anticosti Island (Canada), New York, Oslo, Gotland, Estonia, Thuringia, Bohemia, Podolia, and Kazakhstan. The research bridges gaps in enigmatic records, such as Cornwall's, while emphasizing the significance of Eastern and Southern England's concealed strata. This comprehensive approach enhances global understanding of Silurian stratigraphy.
Early athyride brachiopod evolution through the Ordovician-Silurian mass extinction and recovery, Anticosti Island, eastern Canada
A new understanding of early athyride brachiopod evolution through the Ordovician-Silurian mass extinction and recovery on Anticosti Island, eastern Canada, has been revealed. The study reexamines four genera (Hindella, Cryptothyrella, Koigia, and Hyattidina) based on their internal structures, transferring them from Meristellinae to Hindellinae subfamily. Key findings include the identification of Elkanathyris pallulan as a posteriorly ribbed hindellide of Aeronian age and the discovery that Hindella became extinct during the last Ordovician mass extinction event, which also extinguished the Laframboise reefs. Post-extinction recovery was pioneered by small-shelled Koigia in the basal Silurian Becscie Formation. The research refines biostratigraphy around the O-S boundary and sheds light on the nature of this critical mass extinction event.
Late Ordovician (Hirnantian) diploporitan fauna of Anticosti Island, Quebec, Canada: implications for evolutionary and biogeographic patterns
A rare discovery of Late Ordovician (Hirnantian) diploporitan echinoderms, including Holocystites salmoensis and an unidentified holocystitid, from the Ellis Bay Formation on Anticosti Island, Quebec, Canada, provides critical insights into their evolutionary origins and biogeographic patterns. These fossils extend the known ancestry of the Silurian Holocystites Fauna by at least 15 million years, challenging previous assumptions about its origination. The study highlights the significance of uncovering underrepresented time periods in Earth's history to better understand evolutionary transitions. By analyzing reefal facies and disarticulated crinoid ossicles, researchers offer a unique perspective on noncrinoid echinoderm dynamics during this pivotal geological boundary.
A high-resolution, continuous δ13C record spanning the Ordovician–Silurian boundary on Anticosti Island, eastern Canada
A high-resolution, continuous δ13C record from Anticosti Island reveals distinct isotopic excursions at the Ordovician–Silurian boundary, offering a more precise and complete stratigraphic framework than previous studies. The record identifies two positive Hirnantian Isotope Carbon Excursions (HICE), with peak values of +2.5‰ in the lower part of the Ellis Bay Formation and +4.5‰ in its upper section, suggesting the O–S boundary may be stratigraphically higher than previously thought. This study rectifies gaps in earlier δ13C curves by sampling a nearly complete 300-meter interval at high resolution (∼0.5 m), providing a more accurate depiction of global isotopic trends. The findings highlight the significance of active subsidence and moderate water depths in preserving this sedimentary succession, which captures a comprehensive and reliable δ13C record across the critical O–S transition.
Contributions of digestive plasticity to the ability of white-tailed deer to cope with a low-quality diet
White-tailed deer on Anticosti Island exhibit significant digestive plasticity, enabling them to sustain high population densities despite harsh forage conditions. These deer show increased ruminal volume and digesta load (43% and 62%, respectively), greater absorption surface of ruminal papillae, and larger relative mass of forestomachs compared to mainland counterparts. Despite similar digestibility of woody forage, faster kinetic digestion may occur in Anticosti Island deer. This study highlights the adaptive role of digestive plasticity in coping with low-quality diets, providing insights into how populations adapt to dietary challenges.
Geological characteristics and petroleum resource assessment of the Macasty Formation, Anticosti Island, Quebec, Canada
A significant volume of in-place hydrocarbon resources, estimated at 32.3 billion barrels of oil (BBO) and 52.4 trillion cubic feet (TCF) of natural gas, has been identified in the Macasty Formation on Anticosti Island, Quebec, Canada. This assessment, using the dual porosity model of the GSC, represents the first independent evaluation leveraging both public domain data and confidential operator information. The study highlights a 78% oil to 22% gas ratio, with notable uncertainty due to sparse and varied data coverage. Previous industry estimates suggested around 42.9 billion barrels of oil equivalent, aligning closely with this study's P50 result of 42.1 billion barrels of oil-equivalent. The research did not evaluate recovery rates due to a lack of production data.
Late Ordovician jaw-bearing polychaetes from Anticosti Island, eastern Canada, and their biogeographic significance
A diverse assemblage of jaw-bearing polychaetes (scolecodonts) from the Late Ordovician rocks of Anticosti Island, eastern Canada, reveals strong biogeographic connections between Laurentia and Baltoscandia during a critical period in Earth's history. The study, which analyzed 10 samples containing approximately 30 species, documents several first occurrences for Laurentia, including the family Xanioprionidae and genera such as Pistoprion, Tetraprion, and Rakvereprion. The findings suggest that the closing Iapetus Ocean did not act as a barrier to polychaete dispersal, despite some Laurentian influence indicated by hadoprionid occurrences. Distinct differences between Katian Vauréal and Hirnantian Ellis Bay assemblages likely reflect local environmental changes rather than the initial phase of the Hirnantian mass extinction. This research sheds new light on the biogeographic dynamics during a pivotal interval in the evolution of marine life.
Refining 2 km of Ordovician chronostratigraphy beneath Anticosti Island utilizing integrated chemostratigraphy
A groundbreaking refinement of the Ordovician chronostratigraphy beneath Anticosti Island, Canada, reveals a detailed 2 km-thick sedimentary record spanning from Floian to Hirnantian stages. This study combines high-resolution chemostratigraphy with updated biostratigraphy, identifying precise ages for six formations: Romaine (Floian to early Darriwilian), Mingan (middle Darriwilian to Sandbian), Macasty (lower to mid-Katian), lower Vauréal (upper Katian), upper Vauréal (uppermost Katian), and Ellis Bay (Hirnantian). The research utilized portable X-ray fluorescence analysis on 1414 core samples, alongside carbon isotope and strontium ratio analyses, to establish the duration of depositional sequences and sedimentation rates. This integrated approach significantly enhances the understanding of Anticosti Island's geological history.
Southern continuation of the Wakeham Group and Robe-Noire mafic suite (eastern Grenville Province) from hydrocarbon-targeted seismic reflection data on Anticosti Island, Quebec, Canada
A seismic reflection study on eastern Anticosti Island, Quebec, has identified the southern extension of the Mesoproterozoic Wakeham Group and Robe-Noire mafic sills, previously exposed only along the north shore of the Gulf of St. Lawrence. The research used hydrocarbon-targeted seismic data to image subparallel reflections below the Paleozoic St. Lawrence Platform, revealing a reflective unit characterized by broad open folds, subparallel markers, and east-northeast-dipping faults. This discovery extends geological understanding of the eastern Grenville Province's basement structure, providing new insights into the region's tectonic history.
Additional insights on fracture patterns in the northern Anticosti Basin from satellite, aerial and bathymetric images
A study of the Anticosti Basin reveals that satellite imagery captures fracture patterns more accurately than aerial images, identifying two primary fracture sets trending ~N105 and ~N15. These findings align with field observations but contradict lineaments seen in aerial images, which are deemed unreliable for reflecting actual fracture patterns. The research utilized a combination of satellite, aerial, and bathymetric data to analyze the northern Anticosti Basin's geological structure, providing new insights into its tectonic history.
An example of phenotypic adherence to the island rule? – Anticosti gray jays are heavier but not structurally larger than mainland conspecifics
Gray jays on Anticosti Island, Québec, exhibit a unique phenotypic adherence to the island rule—being approximately 10% heavier than mainland conspecifics without structural size differences. This challenges the assumption that insular populations must evolve distinct genetic traits to achieve larger body masses. Researchers compared body size and mass of gray jays from Anticosti with three mainland populations (two in Québec, one in Ontario) and found no evidence of structural enlargement, suggesting that increased body mass may result solely from denser packing within a mainland-sized frame. This phenomenon could be advantageous in Anticosti's high-density, predator-free environment, offering a potential model for the initial phenotypic step toward island rule compliance.
Geometry and regional significance of joint sets in the Ordovician-Silurian Anticosti Basin: new insights from fracture mapping
A systematic set of fractures trending ~N100, likely extending to significant depths, has been identified in the Ordovician-Silurian Anticosti Basin. These joints, older and more continuous than a secondary set trending ~N10, exhibit median spacing of approximately 1 m and are partly controlled by mechanical bed characteristics. Some joints show notable horizontal and vertical continuity, suggesting potential influence on subsurface fluid flow if open at depth. The study, based on fracture mapping near Havre-Saint-Pierre, the Mingan Islands, and Anticosti Island, interprets these systematic fractures as having formed in a forebulge setting during local extension.
Polygenetic (Polyphase) Karsted Hardground Omission Surfaces In Lower Silurian Neritic Limestones: Anticosti Island, Eastern Canada
Research on Anticosti Island, Québec, reveals the existence of polygenetic (polyphase) karsted hardground omission surfaces in Lower Silurian Chicotte Formation limestones. These surfaces, formed through combined marine and meteoric diagenesis, include planar erosional bedding tops, scalloped erosional surfaces, knobs, ridges, swales at bedding contacts, and paleoscarps. The study proposes that these features are linked to specific diagenetic–depositional processes in terrestrial–peritidal–shallow neritic zones, influenced by fluctuations in relative sea level. These processes include karst corrosion, peritidal–shallow subtidal erosion, subtidal seawater flushing and cementation, and shallow subtidal deposition. The surfaces are interpreted to have been the result of initial extensive shallow-water synsedimentary lithification forming hardgrounds, which were planed by inner-neritic abrasion, altered by exposure and subaerial corrosion, and buried by sediments as sea level rose again. This succession was repeated several times, resulting in a suite of recurring polyphase omission surfaces through many meters of stratigraphic section. The study also notes that these Silurian inner-neritic–strandline omission surfaces are temporally unique, part of a suite of marine omission surfaces mostly found in early to middle Paleozoic neritic carbonate sedimentary rocks.
A New Noncalcified Thallophytic Alga from the Lower Silurian of Anticosti Island, Eastern Canada
A newly discovered noncalcified thallophytic alga, Menieria minuta, from the Lower Silurian of Anticosti Island, provides rare fossil evidence of soft algal meadows that may have been widespread in Early Paleozoic deepwater subtidal environments. This delicate alga, characterized by a central axis with lateral branches and helically arranged appendages, formed significant biomass alongside brachiopods, suggesting parallels to modern sea grass meadows. The discovery sheds light on the ecological dynamics of photic-zone paleocommunities during this geological period.
Early Silurian ‘algal meadows’ of Anticosti Island, eastern Canada: an analogue to modern sea grass meadows?
Research on Anticosti Island, eastern Canada, reveals that Early Silurian thallophytic algal meadows may have functioned as significant carbon sinks, analogous to modern sea-grass meadows or kelp forests. This discovery suggests that these ancient algae played a crucial role in assimilating CO2 during the early Palaeozoic era, when complex life was predominantly marine and lacked the diversity of today's ecosystems. The study, based on well-preserved fossil records from Anticosti, proposes that thallophytic algae were major primary producers, contributing substantially to carbon sequestration despite their soft-bodied nature and sporadic fossil record.
Soil-vegetation relationships on a cobbly limestone floodplain. Anticosti Island, Quebec
Research on Anticosti Island's Galiote River floodplain reveals distinct soil-vegetation relationships shaped by limestone substrates. Four dominant shrub associations—Dryadetum drummondi, Juniperetum horizontalis, Dryadetum integrifolae, and Potentilletum fruticusae—alongside six less prominent herbaceous communities, were identified. These plant communities colonize calcareous soils with high pH (>7) and base saturation (>100%), classified under Regosolic, Brunisolic, and Gleysolic orders. Pioneer plants like Dryas stabilize the substrate, facilitating succession from riverine to forested ecosystems along a topographical gradient. Four new subassociations were described, highlighting the interplay between soil conditions and vegetation dynamics in this unique limestone floodplain environment.
The stratigraphic imprint of a mid-Telychian (Llandovery, Early Silurian) glaciation on far-field shallow-water carbonates, Anticosti Island, Eastern Canada; pp. 207–213
A mid-Telychian (Llandovery, Early Silurian) glaciation event is identified through its stratigraphic imprint on shallow-water carbonates at Anticosti Island, eastern Canada. The study reveals a far-field record of this glaciation, marked by three distinct facies associations—carbonate, mixed siliciclastic-carbonate, and encrinitic—along the south-central coast. These deposits, characterized by high-energy storm features, indicate episodic sedimentation influenced by glacio-eustasy. A multi-order transgressive-regressive (TR) sequence framework, superimposed on a long-term regressive trend, highlights the impact of far-field glaciation on shallow-water environments. The Jupiter–Chicotte formational boundary serves as a key discontinuity surface, correlating with the onset of this mid-Telychian glaciation.
A large herbivore triggers alternative successional trajectories in the boreal forest
A 15-year study on Anticosti Island, Quebec, reveals that deer herbivory can trigger alternative successional trajectories (AST) in boreal forests. The research found that while palatable species like paper birch and certain herbs recovered after logging, woody regeneration was dominated by white spruce, and grasses became abundant in the field layer. This suggests that even limited browsing during early succession may lead to distinct climax states, with late-successional broadleaf species and balsam fir remaining rare. The study compared exclosures built immediately after logging with those constructed eight years later, demonstrating lasting legacies of herbivory on plant composition.
Quasiaulacera, a new Hirnantian (Late Ordovician) aulaceratid stromatoporoid genus from Anticosti Island, Canada
Researchers have discovered Quasiaulacera, a new genus of aulaceratid stromatoporoids from the Hirnantian (Late Ordovician) period on Anticosti Island, Canada. This genus, characterized by its large, columnar form and unique structural features, includes two species: Q. stellata and Q. occidua. The study reveals that Quasiaulacera thrived during a period of global cooling linked to the Hirnantian glaciation but faced extinction at the Ordovician-Silurian (O/S) boundary. This finding supports evidence that the Hirnantian era was marked by both innovation and migration in tropical latitudes, despite significant generic loss. The research combines detailed morphological analysis with stratigraphic data from the Ellis Bay Formation to elucidate the evolutionary dynamics of stromatoporoids during this critical period.
The Ordovician-Silurian boundary (late Katian-Hirnantian) of western Anticosti Island: revised stratigraphy and benthic megafaunal correlations
A revised stratigraphy of the Ellis Bay Formation on western Anticosti Island reveals critical insights into one of Earth's most significant mass extinction events, marking the transition from the Ordovician to Silurian periods. The study identifies three new members—Fraise, Juncliff, and Parastro—within this formation, which spans approximately 80–90 meters and captures the Hirnantian shelly fauna's onset near its base. This fauna, characterized by brachiopods like Eospirigerina and Hindella, ends abruptly at the top of the reefal Laframboise Member, coinciding with a major extinction event that wiped out Hirnantian brachiopods, stromatoporoids, corals, crinoids, and nautiloids. The recovery in the earliest Silurian (Rhuddanian) is marked by small-shelled brachiopod faunas, including both Ordovician hold-over taxa and new arrivals like Viridita and Koigia. This revision highlights the formation's role as a key record of environmental changes during this pivotal period.
Basin-Scale Assessment for CO2 Storage Prospectivity in the Province of Québec, Canada
A basin-scale assessment identifies the St. Lawrence Lowlands sub-basin as the most promising for CO2 storage in Québec, Canada, due to its excellent reservoir-seal pairs and proximity to large CO2 emitters. The study evaluates four Paleozoic sedimentary basins, finding that while the Anticosti sub-basin and Magdalen basins show geological potential, their offshore locations and limited infrastructure hinder their viability. Conversely, the Appalachian and Gaspé Belt basins exhibit very low prospectivity, except for the northeastern part of the Gaspé Peninsula. This assessment combines geological data with emissions analysis to prioritize regions for future CO2 storage development.
Early Silurian (Aeronian) East Point Coral Patch Reefs of Anticosti Island, Eastern Canada: First Reef Recovery from the Ordovician/Silurian Mass Extinction in Eastern Laurentia
A significant discovery on Anticosti Island, eastern Canada, reveals the earliest evidence of reef recovery following the devastating Ordovician/Silurian mass extinction. This study identifies a late Aeronian patch reef swarm spanning 60–70 km, comprising over 100 reefs up to 80 meters in diameter and 10 meters high. These reefs, built primarily by tabulate and rugose corals alongside stromatoporoids, represent the first phase of reef recovery after a 5–6 million-year gap. The reefs exhibit unique symbiotic intergrowths between corals and stromatoporoids, along with a diverse array of calcifying cyanobacteria, crinoids, brachiopods, and green algae. The research also redefines the Menier Formation within the North American Stratigraphic Code, encompassing the lower two members of the existing Jupiter Formation.
Is hunting an effective tool to control overabundant deer? A test using an experimental approach
Despite extensive efforts to reduce white-tailed deer populations on Anticosti Island through targeted hunting, the study found no significant difference in deer density or vegetation recovery between experimental and control sites. The research aimed to achieve a 50% reduction in antlerless deer in five 20-km² areas during 2002–2006 but succeeded at only 93% of its harvest objectives, with subsequent years falling short. Monitoring over six years revealed that deer density and vegetation dynamics varied stochastically rather than responding to hunting pressure. The study proposes multiple hypotheses—including compensatory population mechanisms, hunter access limitations, and recolonization—to explain the lack of observed impact. These findings suggest that sport hunting may be an ineffective tool for controlling cervid populations in natural environments, challenging conventional management strategies.
Large herbivore effects on songbirds in boreal forests: lessons from deer introduction on Anticosti Island
Abundant white-tailed deer populations on Anticosti Island, Quebec, Canada, have significantly altered boreal forest understory vegetation and homogenized songbird communities by reducing the presence of understory-dependent species. Compared to the neighbouring Mingan Archipelago, where deer are absent, balsam fir stands on Anticosti showed a sevenfold lower mean cover of trees at 0–2 m height, leading to less diverse songbird communities. The study suggests that intensive browsing by deer triggers trophic cascades, affecting animal diversity in boreal forests, albeit with less dramatic effects than observed in temperate forests. This research underscores the negative impacts of high herbivore densities on ecosystem dynamics and highlights the role of top-down factors in regulating community structure.
Lipid biomarkers record fundamental changes in the microbial community structure of tropical seas during the Late Ordovician Hirnantian glaciation
A significant discovery from the Late Ordovician Hirnantian glaciation reveals that enhanced methane cycling played a crucial role in climate feedback during warm intervals. This was evidenced by high abundances of 3β-methylhopanes, sourced from aerobic methanotrophic bacteria, which were found to correlate positively with paleotemperature proxies across multiple tropical marine basins. The study analyzed lipid biomarkers in thermally preserved strata from Anticosti Island (Canada), the Cincinnati Arch (USA), and Nevada (USA). Despite oceanographic differences, these localities showed similar biomarker profiles, particularly in hopane/sterane ratios, indicating shifts in bacterial versus algal primary production. The findings suggest that methane cycling could have been a key positive feedback mechanism on climate during extended warm periods of early Paleozoic time.
Regional Stratigraphic, Depositional, and Diagenetic Patterns of the Interior of St. Lawrence Platform The Lower Ordovician Romaine Formation, Western Anticosti Basin, Quebec
A comprehensive analysis of the Great American Carbonate Bank (GACB) reveals significant insights into its stratigraphic, depositional, and diagenetic patterns, particularly within the Lower Ordovician Romaine Formation in the western Anticosti Basin, Quebec. This study identifies distinctive lithofacies and fauna that provide a robust chronostratigraphic framework for correlating disparate outcrops and subsurface data, enhancing our understanding of the bank's depositional history and evolution. The research integrates biostratigraphy, ichnology, stratigraphy, and diagenesis to shed light on the GACB's economic potential, including its role as a source of hydrocarbons, minerals, and construction materials. Additionally, it explores the bank's potential as an aquifer or waste repository, contributing valuable data for both scientific and practical applications.
Sediment Dynamics and Stratigraphic Architecture of a Lower Silurian Storm-dominated Carbonate Ramp, Anticosti Island, Québec, Canada
Research on Anticosti Island, Québec, reveals the sediment dynamics and stratigraphic architecture of a Lower Silurian storm-dominated carbonate ramp. The study identifies three distinct facies associations along an E-W outcrop belt, characterized by episodic high-energy storm events such as hummocky cross-stratification and wave-enhanced sediment-gravity flows. Spatial and temporal changes in siliciclastic content suggest transitions from arid to humid climatic conditions and basin margin depositional environments. A major faunal shift, dominated by crinoids, is linked to increased siliciclastic supply and rapid sea level fluctuations. The stratigraphic architecture is driven by glacio-eustasy, with a 4th order transgressive-regressive sequence and superimposed 5th/6th order meter-scale cycles. An open-ramp model with a concave-up profile and steep inner ramp is proposed to explain the observed patterns.
The Early Silurian Gun River Formation of Anticosti Island, eastern Canada: A key section for the mid-Llandovery of North America
A revised stratigraphic analysis of the Early Silurian Gun River Formation on Anticosti Island, Quebec, reveals a 85–100 m thick carbonate succession deposited in a deepening, tropical carbonate ramp or shelf. The formation is divided into four members (Lachute, Innommee, Sandtop, and Macgilvray), providing critical insights into the mid-Llandovery period following the Late Ordovician mass extinctions. The study demonstrates gradual faunal turnover from low-diversity Rhuddanian communities to more diverse mid-Aeronian assemblages, marked by abundant large pentamerids, indicating sustained deposition without major sedimentary gaps. Deposition occurred at 30–60 m water depths, 40–80 km offshore from the Laurentian craton, with evidence suggesting periodic sub-storm wave base conditions in southern tropical latitudes (20°–25° S). The absence of shallow-water reefs and ooid shoals further supports this interpretation.
Greenland halibut (Reinhardtius hippoglossoides Walbaum, 1792) early stage distribution in the Gulf of St. Lawrence
A first-of-its-kind study on the early life stages of Greenland halibut in the Gulf of St. Lawrence reveals late-winter spawning, likely in the deep Laurentian Channel southwest of Newfoundland. Using data from ichthyoplankton and bottom trawl surveys conducted between 2005 and 2010, researchers identified larvae primarily south and north of Anticosti Island in April-May, with postlarvae concentrated north of the island by August. Larval distribution patterns suggest hatching occurred in late March or early April, providing critical insights into the species' reproductive cycle and habitat use.
High-Resolution Carbon Isotope Stratigraphy of the Ordovician-Silurian Boundary on Anticosti Island, Quebec: Regional and Global Implications
A high-resolution carbon isotope analysis of the Ordovician-Silurian boundary on Anticosti Island, Quebec, reveals a distinct isotopic pattern that challenges current models of the global carbon cycle during the Late Ordovician. The study, which examined over 400 micritic limestone samples from six sections of the Ellis Bay Formation, identified two significant positive carbon isotope excursions (∼2‰ and ∼4‰) that align with global graptolite-rich Hirnantian successions. This pattern contradicts existing predictions, suggesting a more complex evolution of the carbon cycle than previously understood. The research integrates isotopic data with sequence stratigraphy and biostratigraphy to provide new insights into this critical period of Earth history.
Revision of the position of the Ordovician–Silurian boundary in southern Ontario: regional chronostratigraphic implications of δ13C chemostratigraphy of the Manitoulin Formation and associated strata
A significant revision of the Ordovician–Silurian boundary position is proposed based on δ13C chemostratigraphy from southern Ontario, suggesting the Manitoulin Formation is latest Ordovician (Hirnantian) rather than earliest Silurian. The study identified a Hirnantian isotope carbon excursion (HICE) in the upper Queenston Formation to lower-middle Manitoulin Formation, supporting this conclusion and aligning with biostratigraphic data from conodonts and brachiopods. Notably, the HICE is absent on Manitoulin Island but present in the Bruce Peninsula and adjacent regions, indicating age variations across the area. This challenges the traditional boundary placement at the base of the Manitoulin Formation, instead suggesting it lies near the base of the overlying Cabot Head Formation. These findings have major implications for interpreting the geologic history and marine depositional patterns of the latest Ordovician in North America.
Terminal Ordovician carbon isotope stratigraphy and glacioeustatic sea-level change across Anticosti Island (Quebec, Canada)
A detailed carbon isotope analysis of Ordovician-Silurian boundary strata on Anticosti Island, Quebec, reveals that the Hirnantian positive carbon isotope excursion—characteristic of global records—peaks at ~4.5‰ in carbonate rocks. This excursion, coupled with glacioeustatic sea-level fluctuations, suggests that sea-level drawdown and subsequent rise were not perfectly synchronized with the isotopic shift. The study proposes that the entire Hirnantian Stage on Anticosti is confined to the Laframboise and lower Fox Point Members, supported by a combined litho- and chemostratigraphic approach. Discontinuities in the isotope curve across proximal-to-distal transects further indicate diachroneity in sedimentary deposits, with oncolite beds transgressing westward while Becscie limestones prograded eastward. The findings align with the 'weathering' hypothesis for the Hirnantian carbon isotope excursion, providing insights into terminal Ordovician climate dynamics.
A structural study of western Anticosti Island, St. Lawrence platform, Quebec: a fracture analysis that integrates surface and subsurface structural data
A structural analysis of western Anticosti Island, Quebec, reveals that fracture systems and faults in the region are influenced by multiple tectonic events, including Taconian, Acadian, Jurassic, and Quaternary deformations. The study identifies four primary fracture sets—two orthogonal (NS-EW) potentially linked to Early Acadian extensional stresses, and two others (N40–70° and N135–165°) possibly formed during the Middle Devonian Acadian orogeny or later Jurassic tectonics. Irregular fractures may result from post-glacial isostatic rebound. The research integrates field data, remote sensing, and seismic reflection to assess how these structures influenced petroleum migration on the Anticosti Platform, suggesting that Taconian and Early Acadian faults played a significant role in reservoir development.
Chitinozoan biostratigraphy of a new Upper Ordovician stratigraphic framework for Anticosti Island, Canada
A new Upper Ordovician stratigraphic framework for Anticosti Island, Canada, reveals significant east-west correlations between the Ellis Bay and Vauréal formations, resolving long-standing discrepancies. Chitinozoan biostratigraphy demonstrates that most strata of the Ellis Bay Formation at the eastern end correlate with the mid-upper Vauréal Formation in the west, while the Schmitt Creek and Mill Bay members of the Vauréal are older than the uppermost Vauréal eponym members. The study also identifies a Hirnantian age for the gamachiana Zone and provides insights into the timing and magnitude of the Hirnantian Isotopic Carbon Excursion (HICE), aligning with global stratigraphic data from China and Scotland. This research integrates chitinozoan, geochemical, sedimentological, and sequence stratigraphic data to refine understanding of Upper Ordovician stratigraphy.
Endobiotic cornulitids in Upper Ordovician tabulate corals and stromatoporoids from Anticosti Island, Quebec
A new species of endobiotic cornulitid, Cornulites celatus n. sp., has been discovered within Upper Ordovician tabulate corals and stromatoporoids from Anticosti Island, Quebec. This finding extends the known stratigraphic range of cornulitids in commensal relationships with these organisms back to the Upper Ordovician, previously thought to begin in the Silurian period. The study also reveals a more limited paleoenvironmental distribution for C. celatus compared to its principal coral host, Propora conferta, suggesting environmental specificity in their association. Growth interference patterns indicate a commensal relationship between the endobiotic cornulitid and its hosts, including Paleofavositessp., Acidolites arctatus, A. compactus, and Ecclimadictyonsp. The diagnosis of Cornulites is emended to include forms with a distinctive two-layered shell wall, characterized by an outer layer of prismatic calcite.
Influence of Density and Climate on Population Dynamics of a Large Herbivore Under Harsh Environmental Conditions
A study on Anticosti Island, Canada, reveals that population density and autumn-spring climate conditions significantly influence the dynamics of white-tailed deer (Odocoileus virginianus), a large herbivore thriving at its northern range limit under harsh environmental conditions. Despite severe winters with scarce forage and abundant snow, the population showed increased growth over 23 years, with adult survival rates comparable to other populations but lower reproduction rates. Density at estrus primarily affected reproduction in younger females (2–4 years old) and prime-aged females (5–9 years), while spring conditions favoring high-quality forage likely impacted neonatal survival in older females (≥10 years). Unlike typical northern ungulate studies, this research highlights the dominant role of autumn-spring climate alongside density rather than winter severity. These findings underscore the importance of considering population density and seasonal climate in management strategies for such populations.
La mer de Goldthwait au Québec
The Goldthwait Sea, a late- and post-Glacial marine invasion in the St. Lawrence Estuary and Gulf east of Québec City, submerged approximately 25,000 km² of land, including significant areas along both shores and Anticosti Island. This study identifies three main periods (Goldthwaitian I, II, III) within a 14,000-year timeline of land emergence, though geographical subdivisions remain challenging due to limited well-developed shorelines. Rapid isostatic recovery, occurring at about 75% during the first 3,000 years post-deglaciation, highlights the dynamic nature of this region's geological history.
Late Ordovician and Early Silurian stromatoporoid sponges from Anticosti Island, eastern Canada Crossing the O/S mass extinction
Stromatoporoid sponges, once dominant in Late Ordovician and Early Silurian shallow tropical seas, thrived in the Anticosti Basin (Gulf of St. Lawrence), forming extensive calcium carbonate skeletons—some over a meter wide—in reefs and deeper shelf environments near the photic zone's edge. This study highlights their fossil record across a critical global mass extinction boundary, revealing both the taxa that perished during this transition and the subsequent repopulation of equatorial seas. By analyzing the basin's exceptionally well-preserved carbonate sequence, researchers reconstructed ecological shifts, providing insights into resilience and recovery in marine ecosystems following major extinction events.
Ordovician–Silurian Lilliput crinoids during the end-Ordovician biotic crisis
A rapid reduction in body size, known as the 'Lilliput Effect,' was observed in crinoids from Anticosti Island during the end-Ordovician biotic crisis. This significant decrease in size affected both dominant Ordovician and Silurian clades equally, with the post-extinction fauna consisting largely of new taxa. The miniaturization occurred rapidly but recovery took up to 7 million years, highlighting a macroevolutionary asymmetry that underscores the importance of preserving current biodiversity.
Preindustrial reconstruction of a perhumid midboreal landscape, Anticosti Island, Quebec
Research on Anticosti Island, Quebec, reveals that preindustrial balsam fir forests exhibited rare stand-initiating events over the past 160 years, challenging the conventional cyclic disturbance model. Using historical forest maps and dendrochronology, scientists reconstructed a landscape dominated by overmature softwood stands with sporadic younger inclusions, suggesting an alternative dynamics model for maritime eastern Canada's balsam fir ecosystems. This finding implies that sustainable forest management should align with this natural variability to preserve ecological integrity.
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