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

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.

2017 ◽  
Vol 54 (12) ◽  
pp. 1248-1262 ◽  
Author(s):  
Carole J. Burrow ◽  
Susan Turner ◽  
John G. Maisey ◽  
Sylvain Desbiens ◽  
Randall F. Miller

The higher taxonomic affinities of fin spines from the Lower Devonian (Emsian) Atholville beds, Campbellton Formation, near Campbellton, New Brunswick, Canada, originally identified as Ctenacanthus latispinosus, have been uncertain since they were first described by Whiteaves in the late 19th century. Woodward subsequently referred the species to Climatius, because the isolated Canadian fin spines were similar to those preserved in articulated specimens of Climatius reticulatus from the Lower Old Red Sandstone (Lochkovian) of Scotland. Spines of the same form as the Atholville beds specimens are also found in Emsian mudstones on the Gaspé Peninsula, Québec. One of the fin spine forms appears identical to the pectoral fin spines on an articulated specimen from the Campbellton Formation that has been assigned to the stem chondrichthyan Doliodus problematicus, a taxon erected for isolated diplodont teeth. By comparison with median and paired fin spine morphology on the climatiiform Climatius reticulatus from the Scottish Lower Old Red Sandstone and the spines preserved on the articulated Doliodus, isolated fin spines from Campbellton and several localities on the Gaspé Peninsula are now identified as belonging to Doliodus latispinosus comb. nov. The variety of spine morphotypes recognized—pectoral, prepelvic, prepectoral, and median—support a phylogenetic position within the “acanthodians” rather than “conventionally defined chondrichthyans”.


2004 ◽  
Vol 41 (5) ◽  
pp. 489-505 ◽  
Author(s):  
Esther Asselin ◽  
Aïcha Achab ◽  
Azzedine Soufiane

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.


Waterbirds ◽  
2015 ◽  
Vol 38 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Shawn R. Craik ◽  
Alan R. Hanson ◽  
Rodger D. Titman ◽  
Matthew L. Mahoney ◽  
Éric Tremblay

1990 ◽  
Vol 64 (2) ◽  
pp. 184-199 ◽  
Author(s):  
Graham A. Young ◽  
James P. A. Noble

Six species belonging to the families Proporidae and Plasmoporidae occur in the Lower and Upper Silurian rocks of the Limestone Point and La Vieille Formations of northern New Brunswick and of the Anse à Pierre-Loiselle, La Vieille, and Gascons Formations of the Gaspé Peninsula of Québec. The three species ofProporaare widely distributed but show varying faunal affinities, while both species ofPlasmopora, Plasmopora loganiandPlasmopora corrugata, are new and are almost endemic. Revised concepts ofProporaandPlasmoporaare proposed. The holotype specimen for the type species ofCamptolithuswas examined and confirms the genus as distinct fromPropora, rather than a synonym as has been previously suggested.The facies distribution of these corals is variable. In general, the proporids, which mostly occur in facies indicating shallow carbonate banks and patch reefs, are more restricted in distribution than the plasmoporids, which occur in these facies and also in others representing a variety of open-shelf environments.


1957 ◽  
Vol 89 (8) ◽  
pp. 371-378 ◽  
Author(s):  
F. T. Bird ◽  
D. E. Elgee

An outbreak of the European spruce sawfly, Diprion hercyniae (Htg.), was discovered in the Gaspé Peninsula in 1930. By 1938, heavy infestations had developed west of the Gaspé Peninsula in Quebec, throughout New Brunswick and northern Maine, and in parts of Vermont and New Hampshire. Moderate to light infestations occurred through all other parts of the spruce forests of this region and extended from Nova Scotia, to the north shore of the St. Lawrence River, and west to Ontario.


1993 ◽  
Vol 30 (12) ◽  
pp. 2283-2294 ◽  
Author(s):  
J. Dostal ◽  
R. Laurent ◽  
J. D. Keppie

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.


Geosciences ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 76 ◽  
Author(s):  
David Didier ◽  
Marion Bandet ◽  
Pascal Bernatchez ◽  
Dany Dumont

Coastal management often relies on large-scale flood mapping to produce sea level rise assessments where the storm-related surge is considered as the most important hazard. Nearshore dynamics and overland flow are also key parameters in coastal flood mapping, but increase the model complexity. Avoiding flood propagation processes using a static flood mapping is less computer-intensive, but generally leads to overestimation of the flood zone, especially in defended urban backshore. For low-lying communities, sea level rise poses a certain threat, but its consequences are not only due to a static water level. In this paper, the numerical process-based model XBeach is used in 2D hydrodynamic mode (surfbeat) to reproduce an observed historical flood in Maria (eastern Canada). The main goal is to assess the impacts of a future storm of the same magnitude in the horizon 2100 according to an increase in sea level rise. The model is first validated from in situ observations of waves and water levels observed on the lower foreshore. Based on field observations of a flood extent in 2010, the simulated flooded area was also validated given a good fit (59%) with the actual observed flood. Results indicate that the 2010 storm-induced surge generated overwash processes on multiple areas and net landward sediment transport and accumulation (washover lobes). The flood was caused by relatively small nearshore waves (Hs < 1 m), but despite small water depth (>1.2 m), high flow velocities occurred in the main street (U > 2 m/s) prior to draining in the salt marsh. The impact of sea level rise on the low-lying coastal community of Maria could induce a larger flood area in 2100, deeper floodwater, and higher flow velocities, resulting in higher hazard for the population.


2006 ◽  
Vol 32 (2) ◽  
pp. 194-211 ◽  
Author(s):  
Tim L Webster ◽  
Donald L Forbes ◽  
Edward MacKinnon ◽  
Daniel Roberts

2007 ◽  
Vol 20 (20) ◽  
pp. 5126-5133 ◽  
Author(s):  
Anders E. Carlson ◽  
Peter U. Clark ◽  
Grant M. Raisbeck ◽  
Edward J. Brook

Abstract Retreat of the Laurentide Ice Sheet (LIS) following the Last Glacial Maximum 21 000 yr BP affected regional to global climate and accounted for the largest proportion of sea level rise. Although the late Pleistocene LIS retreat chronology is relatively well constrained, its Holocene chronology remains poorly dated, limiting our understanding of its role in Holocene climate change and sea level rise. Here new 10Be cosmogenic exposure ages on glacially deposited boulders are used to date the final disappearance of the Labrador sector of the LIS (LS-LIS). These data suggest that following the deglaciation of the southeastern Hudson Bay coastline at 8.0 ± 0.2 cal ka BP, the southwestern margin of the LS-LIS rapidly retreated ∼600 km in 140 yr and most likely in ∼600 yr at a rate of ∼900 m yr−1, with final deglaciation by 6.8 ± 0.2 10Be ka. The disappearance of the LS-LIS ∼6.8 10Be ka and attendant reduction in freshwater runoff may have induced the formation of Labrador Deep Seawater, while the loss of the high albedo surface may have initiated the Holocene Thermal Maximum in eastern Canada and southern Greenland. Moreover, the rapid melting just prior to ∼6.8 10Be ka indicates that the remnant LIS may be the primary source of a postulated rapid rise in global sea level of ∼5 m that occurred sometime between 7.6 and 6.5 cal ka BP.


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