Cryptospore assemblages from Upper Ordovician (Katian–Hirnantian) strata of Anticosti Island, Québec, Canada, and Estonia: Palaeophytogeographic and palaeoclimatic implications

2011 ◽  
Vol 166 (1-2) ◽  
pp. 76-93 ◽  
Author(s):  
Marco Vecoli ◽  
Aurélien Delabroye ◽  
Amalia Spina ◽  
Olle Hints
Keyword(s):  
Upper Ordovician ◽  
Anticosti Island

Maturation thermique et histoire de l'enfouissement et de la génération des hydrocarbures du bassin de l'archipel de Mingan et de l'île d'Anticosti, Canada

1990 ◽  
Vol 27 (6) ◽  
pp. 731-741 ◽  
Author(s):  
Rudolf Bertrand
Keyword(s):  
Carbonate Platform ◽  
Burial History ◽  
Upper Ordovician ◽  
Southeastern Part ◽  
Middle Ordovician ◽  
Oil Generation ◽  
Wide Range ◽  
History Of ◽  
Anticosti Island ◽  
Depth Of Burial

Carbonate platform sequences of Anticosti Island and the Mingan Archipelago are Early Ordovician to Early Silurian in age. With the exception of the Macasty Formation, the sequences are impoverished in dispersed organic matter, which is chiefly composed of zooclasts. Zooclast reflectances suggest that the Upper Ordovician and Silurian sequences outcropping on Anticosti Island are entirely in the oil window but that the Lower to Middle Ordovician beds of the Mingan Archipelago and their stratigraphic equivalents in the subsurface of most of Anticosti Island belong to the condensate zone. Only the deeper sequences of the southwestern sector of Anticosti Island are in the diagenetic dry-gas zone. The maximum depth of burial of sequences below now-eroded Silurian to Devonian strata increases from 2.3 km on southwestern Anticosti Island to 4.5 km in the Mingan Archipelago. A late upwarp of the Precambrian basement likely allowed deeper erosion of the Paleozoic strata in the vicinity of the Mingan Archipelago than on Anticosti Island. Differential erosion resulted in a southwestern tilting of equal maturation surfaces. The Macasty Formation, the only source rock of the basin (total organic carbon generally > 3.5%, shows a wide range of thermal maturation levels (potential oil window to diagenetic dry gas). It can be inferred from the burial history of Anticosti Island sequences that oil generation began later but continued for a longer period of geologic time in the northeastern part than in the southeastern part of the island. Oil generation was entirely pre-Acadian in the southern and western parts of Anticosti Island, but pre- and post-Acadian in the northern and eastern parts.

Upper Ordovician ostracods from the Cautley district, northern England: Baltic and Laurentian affinities

2001 ◽  
Vol 138 (5) ◽  
pp. 589-607 ◽  
Author(s):  
MARK WILLIAMS ◽  
PHILIP STONE ◽  
DAVID J. SIVETER ◽  
PAULINE TAYLOR
Keyword(s):  
North America ◽  
Significant Extent ◽  
Baltic Region ◽  
Upper Ordovician ◽  
Northern Germany ◽  
Iapetus Ocean ◽  
Windermere Supergroup ◽  
Distributional Patterns ◽  
Anticosti Island ◽  
The Baltic

The Cautley Mudstone Formation and Cystoid Limestone Member of the Ashgill Formation (Windermere Supergroup; Ashgill Series), from the Cautley district of northern England, has yielded an ostracod fauna of more than 30 species. Many of these have short ranges, permitting recognition of stratigraphically successive Pusgillian–lower Cautleyan, middle–upper Cautleyan, and Rawtheyan ostracod faunas. Several species are also known from the upper Ordovician of North America (Anticosti Island), Scotland (Girvan district) and the Baltic region (Estonia, glacial erratic boulders of northern Germany), providing evidence to correlate upper Ordovician successions in these areas. The ostracods include abundant podocopes, at some horizons accounting for more than 80% of the fauna. Binodicopes are also common, but palaeocopes are rare. Assemblages are typical of a clastic dominated open marine shelf setting. Diversity at most horizons is low (c. 3–5 species), but reaches a peak of between 13–14 species in middle Cautleyan horizons. Lower diversity at Pusgillian and Rawtheyan horizons coincides with the encroachment of deeper marine-shelf facies which were probably hostile to Ordovician benthonic ostracods. Some of the ostracods (particularly Aechmina) have distributions suggesting tolerance of a range of mid- to deep shelf benthonic palaeoenvironments, but none were pelagic. During Ashgill times the Cautley district (part of palaeocontinental Avalonia) was replete with ostracod genera and species which also occur in the Baltic region (palaeocontinental Baltica; more than 90% generic similarity) and to a lesser, but nonetheless significant extent in North America and Scotland (parts of palaeocontinental Laurentia). Such trans-Tornquist Sea and Iapetus Ocean distributional patterns add to previous ostracod data that support models which show palaeogeographical proximity of Avalonia and Baltica, and Avalonia and Laurentia, by Ashgill times. The widely cited observation, that trans-Iapetus ostracod faunas remained strictly provincial until the mid-or late Silurian, cannot be sustained.

scholarly journals Sedimentology and paleoecology of Upper Ordovician mounds of Anticosti Island, Quebec

1981 ◽  
Vol 18 (10) ◽  
pp. 1562-1571 ◽  
Author(s):  
John H. Lake
Keyword(s):  
Late Ordovician ◽  
Calcareous Algae ◽  
Upper Ordovician ◽  
Salmon River ◽  
Shallow Subtidal ◽  
Anticosti Island ◽  
Primary Porosity

Relatively thin organic buildups in the Ellis Bay Formation of Anticosti Island developed in a shallow subtidal regressive marine shelf environment during the Late Ordovician. The Ellis Bay Formation has been subdivided into six members by Bolton. Two buildups, one in each of members 4 and 6, were studied in detail. The member 6 mud mound on the Salmon River (8 m thick) is bound by calcareous algae, stromatoporoids, and corals, and consists of a micritic bafflestone core capped by crinoidal lime grainstone. Early marine cementation permeated nearly all of the primary porosity. Cathodoluminescence indicates at least five stages of cementation of the mound. Constructive mound development was terminated by progressively shallowing, agitated marine conditions.The member 4 mound is a small coral (ecological) reef exposed on the Vaureal River.

Stratigraphy of the Upper Ordovician upper Vaureal and Ellis Bay formations, eastern Anticosti Island, Quebec

1987 ◽  
Vol 24 (9) ◽  
pp. 1807-1820 ◽  
Author(s):  
D. G. F. Long ◽  
Paul Copper
Keyword(s):  
Late Ordovician ◽  
Eastern Coast ◽  
Upper Ordovician ◽  
New Members ◽  
Patch Reefs ◽  
Accurate Definition ◽  
Central Regions ◽  
Shallow Subtidal ◽  
Anticosti Island ◽  
Definition Of

Marked facies changes occur in Late Ordovician strata, assigned to the uppermost Vaureal and Ellis Bay formations (Ashgill: Rawtheyan–Hirnantian) on Anticosti Island, Quebec. Western Anticosti features shales and carbonates, whereas outcrops along the eastern coast contain prominent, discontinuous, mixed siliciclastic–carbonate units. Detailed section measurement along the northeast coast allows, for the first time, accurate definition of seven new members within this uninterrupted sequence. Sands present in the upper Vaureal and lower Ellis Bay formations in the east appear to have deterred the growth of muddy-bottom brachiopod communities comparable to those in the western and central regions of Anticosti. Sand units within the upper Vaureal Formation contain 1 m diameter colonies of Paleofavosites; coeval small coral patch reefs are found in the central part of the island, where sands are absent. The uppermost Ellis Bay Formation of northeast Anticosti is marked by a shallow, subtidal, coral–algal oncolite bed or by small (2–4 m across, 1–2 m thick) local coral patch reefs, the tops of which have been used to define the Ordovician – Silurian boundary. No supratidal or intertidal sediments and faunas are evident in the Anticosti succession, suggesting that Late Ordovician sea-level drawdown was insufficient to provide shelf-emergent conditions in this region.

Les chitinozoaires de la zone à Climacograptus prominens elongatus de la Formation de Vauréal (Ordovicien supérieur), Ile d'Anticosti, Québec

1977 ◽  
Vol 14 (10) ◽  
pp. 2193-2212 ◽  
Author(s):  
A. Achab
Keyword(s):  
New Species ◽  
Upper Ordovician ◽  
Anticosti Island

The aim of this paper is to describe the chitinozoans from the Climacograptus prominens elongatus Zone from the upper part of the Vaureal Formation (Upper Ordovician) of Anticosti Island. An emendation of the genus Hercochitina is proposed. Seven new species, Hercochitina normalis, H. minuta, H. filamentosa, H. grandispina, Conochitina baculata, C. armifera, and Ancyrochitina spongiosa are described.The microfauna characterized by the dominance of Hercochitina, is distinctive and does not resemble those reported from elsewhere.

scholarly journals Late Ordovician (Hirnantian) diploporitan fauna of Anticosti Island, Quebec, Canada: implications for evolutionary and biogeographic patterns

2018 ◽  
Vol 55 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Sarah L. Sheffield ◽  
William I. Ausich ◽  
Colin D. Sumrall
Keyword(s):  
Evolutionary Dynamics ◽  
Late Ordovician ◽  
Upper Ordovician ◽  
Evolutionary Transitions ◽  
Biogeographic Patterns ◽  
Critical Data ◽  
New Localities ◽  
Reefal Facies ◽  
Anticosti Island ◽  
Fossil Data

Hirnantian (latest Ordovician) localities containing echinoderm fossils are rare; the few that have been discovered primarily contain disarticulated crinoid ossicles. Therefore, relatively little is known about echinoderm evolutionary dynamics across the Late Ordovician – early Silurian boundary, especially noncrinoid echinoderms. New diploporitan echinoderms, Holocystites salmoensis and an unidentified holocystitid, from reefal facies of the Upper Ordovician Ellis Bay Formation of Anticosti Island provide a critical data point concerning diploporitan biogeography and evolutionary pathways undertaken during the Ordovician and Silurian. These fossils also provide a crucial link in understanding the ancestry of the Silurian Holocystites Fauna, an unusual diploporitan fauna from the middle Silurian of North America, whose origination dates back at least 15 million years earlier than previously thought with the discovery of taxa described here. New fossil data such as these stress the importance of uncovering new localities from underrepresented times and places in Earth’s history, so that these evolutionary transitions can be better understood.

Chitinozoan biostratigraphy of a new Upper Ordovician stratigraphic framework for Anticosti Island, Canada

2010 ◽  
Vol 123 (1-2) ◽  
pp. 186-205 ◽  
Author(s):  
A. Achab ◽  
E. Asselin ◽  
A. Desrochers ◽  
J. F. Riva ◽  
C. Farley
Keyword(s):  
Upper Ordovician ◽  
Stratigraphic Framework ◽  
Anticosti Island

Abnormal forms of acritarchs (phytoplankton) in the upper Hirnantian (Upper Ordovician) of Anticosti Island, Canada

2012 ◽  
Vol 173 ◽  
pp. 46-56 ◽  
Author(s):  
Aurélien Delabroye ◽  
Axel Munnecke ◽  
Thomas Servais ◽  
Thijs R.A. Vandenbroucke ◽  
Marco Vecoli
Keyword(s):  
Upper Ordovician ◽  
Anticosti Island

Endobiotic cornulitids in Upper Ordovician tabulate corals and stromatoporoids from Anticosti Island, Quebec

2010 ◽  
Vol 84 (3) ◽  
pp. 518-528 ◽  
Author(s):  
Owen A. Dixon
Keyword(s):  
Coral Species ◽  
Coral Host ◽  
Shell Wall ◽  
Upper Ordovician ◽  
Layered Shell ◽  
Tabulate Coral ◽  
Anticosti Island ◽  
Commensal Relationship ◽  
Stratigraphic Range ◽  
Tabulate Corals

Conoidal shells of Cornulites celatus n. sp. occur commonly within host coralla of Propora conferta Milne-Edwards and Haime, 1851, sensu lato, from the Laframboise Member of the Ellis Bay Formation (Ashgill: Upper Ordovician) at Pointe Laframboise on western Anticosti Island. Examples have also been found at the same locality in the tabulate corals Paleofavosites sp., Acidolites arctatus Dixon, 1986, and A. compactus Dixon, 1986, and the stromatoporoid Ecclimadictyon sp., but not in other associated tabulate coral species. Growth interference between the shells and their hosts indicates a commensal relationship. C.celatus apparently had a more limited paleoenvironmental range than its principal coral host species, which occurs abundantly elsewhere on the island without its endobiotic partner. The diagnosis of Cornulites is emended to include forms having a two-layered shell wall with a distinctive outer layer consistently preserved as prismatic calcite. This new species extends the known stratigraphic range of cornulitids in commensal relationships with corals and stromatoporoids from the Silurian back to the Upper Ordovician.

Biostratigraphic significance of lower Paleozoic microfaunas from eastern Canada

2004 ◽  
Vol 41 (5) ◽  
pp. 489-505 ◽  
Author(s):  
Esther Asselin ◽  
Aïcha Achab ◽  
Azzedine Soufiane
Keyword(s):  
New Brunswick ◽  
Lower Devonian ◽  
Head Group ◽  
Upper Ordovician ◽  
Eastern Canada ◽  
Lower Paleozoic ◽  
Anticosti Island ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula ◽  
Mapping Program

Chitinozoan studies recently carried out in the “Appalachian Forelands and St. Lawrence Platform” National Geoscience Mapping Program (NATMAP) project have confirmed the regional biostratigraphic value of a number of chitinozoan species and led to a better documentation of their stratigraphic and geographic distribution in eastern Canada. The typical Darriwilian microfaunas first described from the Table Head Group of western Newfoundland and containing Conochitina chydaea are now recognised in the Rivière Ouelle Formation at Les Méchins, Gaspé Peninsula. In the Upper Ordovician successions of the St. Lawrence Platform at Neuville and in the Charlevoix area, Quebec, Conochitina primitiva is indicative of the multidens–pre-americanus graptolite zonal range, Hercochitina duplicitas of the americanus Zone, and Hercochitina spinetum and Acanthochitina cancellata characterize the ruedemanni – lower spiniferus zonal interval. The occurrence of Cyathochitina vaurealensis and Hercochitina crickmayi in turbidite deposits of the Grog Brook Group of northwestern New Brunswick confirms the minimal facies dependence of these two Richmondian index species. Eisenackitina dolioliformis, characteristic of the late Aeronian and Telychian successions of Arctic Canada, Gaspé Peninsula, and Anticosti Island, is now recognised in samples from the Upsalquitch Formation of northwestern New Brunswick and the Cabano Formation of the Rimouski area in Quebec. The palynological data from Devonian successions of the Matapedia Valley, the Rimouski area, and the Beauce – Eastern Townships region show that the succession of Lower Devonian chitinozoan assemblages of the Forillon Peninsula based on short-ranging species can be used in establishing regional correlations in the Gaspé Belt.

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