Halysitid corals from Silurian and Devonian rocks of Québec

1980 ◽  
Vol 17 (6) ◽  
pp. 788-796 ◽  
Author(s):  
A. J. Wright ◽  
P.-A. Bourque
Keyword(s):  
West Point ◽  
The West ◽  
Early Devonian ◽  
Gaspe Peninsula ◽  
Different Levels ◽  
Tabulate Corals ◽  
Gaspé Peninsula

Halysitid tabulate corals occur in the Silurian and Devonian rocks of northeastern Gaspé Peninsula, Québec. Silurian specimens from the Dartmouth River and Madeleine River areas are referred to Cystihalysites. A specimen from a possibly Early Devonian level in the Gascons Formation in the Dartmouth River area is assigned to Cystihalysites. Two specimens from different levels in the Early Devonian part of the West Point Formation in the Madeleine River area are assigned questionably to Quepora. The latter occurrences in the West Point Formation demonstrate that this group of tabulate corals lingered into the Devonian.

Halysitid and auloporid tabulate corals from the Gascons and West Point Formations (Silurian), Gaspé, Québec, Canada

1991 ◽  
Vol 65 (5) ◽  
pp. 715-726 ◽  
Author(s):  
Graham A. Young ◽  
Dong-Jin Lee ◽  
James P. A. Noble
Keyword(s):  
New Species ◽  
Environmental Conditions ◽  
West Point ◽  
Reef Facies ◽  
Lower Silurian ◽  
Upper Silurian ◽  
High Degree ◽  
Gaspe Peninsula ◽  
Tabulate Corals ◽  
Gaspé Peninsula

The uppermost Lower Silurian and Upper Silurian Gascons and West Point Formations of the southern Gaspé Peninsula were deposited under a broad range of environmental conditions from deep offshore-shelf to reef facies. Halysitid and auloporid tabulate corals occur in a number of facies and show a high degree of endemism.Two species of Halysitidae and three species of Auloporida are found in these formations. Both halysitids have been previously described from this region. The auloporids include the new species Syringopora minuta and another species that may represent the first known Silurian occurrence of the fletcheriellid genus Pseudofletcheria. A neotype for the halysitid Cystihalysites amplitubulatus (Lambe) is proposed.

Lithostratigraphic Framework and Unified Nomenclature for Silurian and Basal Devonian Rocks in Eastern Gaspé Peninsula, Québec

1975 ◽  
Vol 12 (5) ◽  
pp. 858-872 ◽  
Author(s):  
Pierre-André Bourque
Keyword(s):  
West Point ◽  
The West ◽  
Fine Grained ◽  
Lithostratigraphic Units ◽  
Indian Point ◽  
Stratigraphic Nomenclature ◽  
Gaspe Peninsula ◽  
Eastern Half ◽  
Gaspé Peninsula

A unified stratigraphic nomenclature is proposed for Silurian and basal Devonian rocks in the eastern half of Gaspé Peninsula. The Gascons, West Point and Indian Point Formations of the Chaleurs Bay Synclinorium are extended into the northern part of Gaspé Peninsula. The term St. Léon is restricted to a sequence of mainly fine-grained sediments in which neither the West Point nor the Bouleaux is recognized. The term Lefrançois is abandoned. New lithostratigraphic units here proposed are the Anse à Pierre-Loiselle Formation in the Chaleurs Bay Synclinorium, the Ruisseau Bleau Formation and the Lac McKay Member of the St. Léon Formation in the Mount Alexandre Syncline, and the Ruisseau Louis Member of the St. Léon Formation in the Saint-Jean River Anticline and Mount Alexandre Syncline.

Late Silurian – Early Devonian rifting during dextral transpression in the southern Gaspé Peninsula (Quebec): petrogenesis of volcanic rocks

1993 ◽  
Vol 30 (12) ◽  
pp. 2283-2294 ◽  
Author(s):  
J. Dostal ◽  
R. Laurent ◽  
J. D. Keppie
Keyword(s):  
Rift Zone ◽  
Volcanic Rocks ◽  
Significant Proportion ◽  
Spinel Peridotite ◽  
Initial Surface ◽  
Crustal Material ◽  
Early Devonian ◽  
Ree Patterns ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

The Upper Silurian – Lower Devonian volcanic rocks in the southern Gaspé Peninsula of the Quebec Appalachians crop out at the northeast end of the Connecticut Valley – Gaspé Synclinorium. These shallow marine and subaerial sequences reach a thickness of up to at least 2000 m and comprise two groups: (1) the Late Silurian volcanic rocks, which are mainly transitional alkalic–tholeiitic basalts with steeply sloping REE patterns; (2) the Early Devonian volcanic rocks, which include a significant proportion of intermediate rocks in addition to tholeiitic basalts. Compared with the Silurian rocks, the Devonian basalts have lower abundances of strongly incompatible trace elements such as Ba, Th, Ta, Nb, and light REE and relatively flat heavy REE patterns. Basalts of both groups display negative Nb and Ta anomalies (relative to Th and La).Although the basalts of both sequences were derived from lithospheric mantle, the Silurian basalts were generated from garnet peridotite at ~ 80 km depth while the Devonian basalts appear to have resulted from a larger degree of melting of spinel peridotite at a shallower depth (~ 60 km). Devonian intermediate rocks are probably the result of mixing of the basaltic magma with upper crustal material through assimilation – fractional crystallization processes. The basalts are interpreted to have formed in a northwest-trending rift zone located in the Quebec Reentrant during dextral transpression along the Appalachian Orogen. Rotation during and after the volcanism reoriented the rift zone to a northeast trend. The high density layer at the base of the crust under the Magdalen Basin may be the former magma chamber for the Silurian–Devonian volcanism. The change from transitional to tholeiitic volcanism at the Silurian–Devonian boundary suggests that the stretching value (ratio of final to initial surface area) increased from < 2 to > 2 at that time. This boundary is also coincident with the Salinic disturbance that is inferred to have been produced by erosion of the thermally uplifted block associated with rifting.

A new stratigraphic framework for the Gaspé Belt in southern Quebec: implications for the pre-Acadian Appalachians of eastern Canada

2004 ◽  
Vol 41 (5) ◽  
pp. 507-525 ◽  
Author(s):  
Denis Lavoie ◽  
Esther Asselin
Keyword(s):  
New Brunswick ◽  
Sea Level Rise ◽  
Sea Level ◽  
Eastern Canada ◽  
Early Devonian ◽  
Stratigraphic Framework ◽  
Marine Facies ◽  
Saint Francis ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

The post-Taconian units in the Quebec and northern New Brunswick Appalachians constitute the Gaspé Belt and geological studies have mostly focussed on its eastern Quebec segment. Biostratigraphic data indicate that the succession in southern Quebec is no older than Late Silurian and extends into the Early Devonian. Two distinct stratigraphic assemblages are present. The first assemblage (Saint-Luc, Cranbourne, and Lac Aylmer formations, and Glenbrooke Group) unconformably overlies the Humber and Dunnage zones. The units show a basal alluvial conglomerate that passes progressively to deeper marine facies upsection, which have recorded a post-Late Silurian transgressive event. The second assemblage (Saint-Francis Group and Frontenac Formation) is faulted against either Dunnage units or autochthonous post-Taconian units. It locally unconformably overlies units of the Dunnage Zone; the succession shows progressively deeper marine conditions upsection and also has recorded a post-Late Silurian transgressive event. The biostratigraphic framework suggests that some of the units that were assumed to be vertically stacked are rather laterally equivalent. Independant evidence supports the hypothesis that the Gaspé Belt in southern Quebec formed after the collapse of the Taconian orogen in Late Silurian time. This event is ascribed to the Salinian Orogeny. The framework from southern Quebec is incorporated in a regional scenario. The Gaspé Belt experienced a Pridolian–Lochkovian sea-level rise. In Pragian time, shallower marine conditions were established in southern Quebec, whereas in the Gaspé Peninsula, the shallower conditions only occurred in early Emsian time.

scholarly journals VIII. On the spines, sporangia, and spores of Psilophyton princeps , Dawson, shown in specimens from Gaspé

1931 ◽  
Vol 219 (462-467) ◽  
pp. 421-442 ◽  
Keyword(s):  
Geological History ◽  
Early Devonian ◽  
History Of ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

Psilophyton princeps , though still incompletely known, is one of the most important Early Devonian plants, both on account of its morphology and of the place it occupies in the history of investigation of Pre-carboniferous vegetation. It was originally distinguished and described by Dawson from specimens collected in the Gaspé peninsula, Canada. As shown in the restoration, published in the ‘Geological History of Plants’ (DAWSON, 1882), he regarded the plant as consisting of horizontally growing rhizomes, from which sprang erect branch-systems; the branching was dichotomous and the fine distal ramifications terminated in large ovoid sporangia. From the description (DAWSON, 1871) it is clear that the lower portions of the sub-aerial branch-systems were markedly spiny, while the spines, though present, became less numerous and more distant in the distal, fertile regions. The distribution of the spines according to Dawson is not shown in his restoration; it is well illustrated in a modification of Dawson’s restoration by PIA (1926, fig. 109).

scholarly journals Fossil crinoids from the basal West Point Formation (Silurian), southeast Gaspé Peninsula, Québec, eastern Canada

2016 ◽  
Vol 52 ◽  
pp. 211 ◽  
Author(s):  
Stephen K. Donovan ◽  
David G. Keighley
Keyword(s):  
West Point ◽  
Atlantic Canada ◽  
Upper Ordovician ◽  
Eastern Canada ◽  
North Wales ◽  
Stratigraphic Position ◽  
The Common ◽  
Upper Silurian ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

Silurian strata of Atlantic Canada and southern Québec locally preserve common fossil crinoids, albeit mostly as disarticulated remains. New crinoids from the Chaleurs Group, West Point Formation (Ludlow to Pridoli?; Upper Silurian) of the Gaspé Peninsula include Iocrinus? maennili (Yeltysheva) (otherwise known from the Katian of Estonia), Bystrowicrinus (col.) depressus sp. nov. and Cyclocyclicus (col.) sp. aἀ. C. (col.) echinus Donovan. On the basis of both its gross morphology and stratigraphic position, Iocrinus? maennili is unlikely to be an iocrinid disparid, a family that became extinct at the end of the Ordovician. The trivial name has hitherto been erroneously spelled as männili, mannili and mjannili. Most specimens of the common Bystrowicrinus (col.) depressus appear cyclocyclic because the pentastellate lumen occurs in a deeply sunken claustrum that is commonly occluded by sediment; clean specimens are highly distinctive. Cyclocyclicus (col.) sp. aἀ. C. (col.) echinus is similar to a species known from the Katian of North Wales. Taken together, this assemblage is more reminiscent of Katian strata (Upper Ordovician). Ḁis is problematic given the current mapping of the outcrop as West Point Formation (Upper Silurian), suggesting further stratigraphic studies in the area are required.

Silurian tabulate coral biostratigraphy and biofacies of northern New Brunswick and the southern Gaspé Peninsula

1990 ◽  
Vol 27 (9) ◽  
pp. 1143-1158 ◽  
Author(s):  
Graham A. Young ◽  
James P. A. Noble
Keyword(s):  
New Brunswick ◽  
Relative Abundance ◽  
Large Scale ◽  
The Other ◽  
Region Analysis ◽  
Abundance Data ◽  
Tabulate Coral ◽  
Gaspe Peninsula ◽  
Tabulate Corals ◽  
Gaspé Peninsula

Diverse Early and Late Silurian tabulate coral faunas occur in the Baie des Chaleurs region. Analysis of relative abundance data of tabulate corals from the Limestone Point and La Vieille formations of northern New Brunswick and the Anse à Pierre-Loiselle, La Vieille, and Gascons formations of the southern Gaspé Peninsula allowed the recognition of three recurrent large-scale biofacies: the Propora–Heliolites, Cystihalysites, and Syringopora biofacies. The Syringopora Biofacies lacks the characteristics that would allow a zonation to be produced, but in each of the other biofacies, two zones are erected. These can be applied throughout the Baie des Chaleurs region and may be used for correlation with other areas having faunal affinities with this region.

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