Late Silurian-Early Devonian tectono-sedimentary history of the Gaspe Belt in the Gaspe Peninsula: from a transtensional Salinic basin to an Acadian foreland basin

2001 ◽  
Vol 49 (2) ◽  
pp. 202-216 ◽  
Author(s):  
M. Malo
Keyword(s):  
Foreland Basin ◽  
Early Devonian ◽  
History Of ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

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).

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.

The significance of various garnet types in surficial materials in southeastern Gaspé Peninsula, Quebec

1995 ◽  
Vol 32 (6) ◽  
pp. 730-740 ◽  
Author(s):  
Yvon T. Maurice
Keyword(s):  
Distribution Patterns ◽  
Distribution Data ◽  
Cape Breton Island ◽  
Tectonic Model ◽  
Distinct Source ◽  
History Of ◽  
Late Wisconsinan ◽  
Type 3 ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

The distribution patterns of four types of garnet in surficial materials of southeastern Gaspé Peninsula are interpreted in terms of the glacial history of the area, the lithostratigraphy of the bedrock, and mineral occurrences. Each type is derived from a distinct source, and all have undergone at least some southeastward glacial dispersion. Type 1 garnets, anhedral Ca-garnet fragments, are from the McGerrigle granite metamorphic aureole and were brought into the region by the same ice flow that caused the well-documented southward dispersal of granite debris. Their distribution within the study area depicts the southern part of this important dispersal train with an improved degree of precision. Type 2 garnets, Ca-garnet crystals, seem to be related to skarns within the boundaries of the study area; some patterns cannot be linked to any known source, thus providing challenging exploration opportunities. Type 3 garnets, colored pyralspite garnet crystals, are related to a tectonic breccia within the Maquereau–Mictaw contact zone. Type 4 garnets, Grenville-type anhedral garnets, were not brought into the region by Laurentide ice, as one might suspect, but rather seem to be related to specific horizons within the Silurian Lower Chaleurs Group. On the basis of a palinspastic reconstruction of southern Gaspé Peninsula and a plate tectonic model for the Paleozoic of eastern North America, we propose that these garnets were derived from the erosion of a metamorphic Grenvillian terrane, which presently forms the Northwestern Highlands Zone of Cape Breton Island. The distribution data for this garnet type also lends support to the concept put forth in a previous study whereby a local Late Wisconsinan ice mass penetrated some 5–6 km into the region from the southeast near Saint-Godefroi.

Stratigraphy, depositional setting, and diagenetic history of the Saint-Jules Formation (Upper Devonian or Mississippian), a newly identified post-Acadian red clastic unit in the southern Gaspé Peninsula, Quebec

2002 ◽  
Vol 39 (10) ◽  
pp. 1541-1551 ◽  
Author(s):  
Pierre Jutras ◽  
Gilbert Prichonnet
Keyword(s):  
Middle Devonian ◽  
Upper Devonian ◽  
Clastic Rocks ◽  
Fluvial Processes ◽  
History Of ◽  
Diagenetic History ◽  
Depositional Setting ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

The Saint-Jules Formation, a post-Acadian continental clastic unit previously mapped as part of the Bonaventure Formation (pre-Namurian unit), was recently identified in the southern Gaspé Peninsula of Quebec. The Saint-Jules Formation in the study area is confined to a small post-sedimentary graben. The unit is characterized by fault-controlled, oxidized, and poorly sorted detritus that underwent short transportation by fluvial processes. The Saint-Jules Formation is locally overlain by a massive groundwater calcrete several metres in thickness, which is tentatively correlated with the calcretization event that has affected the base of the La Coulée Formation grey clastics (pre-Namurian unit). The calcrete has developed within the karstified upper beds of the Saint-Jules Formation, which brings new insights into the potential hosts of such calcretes and on the potential stratigraphic confusion that such diagenetic overprints can create. Partial erosion of both the La Coulée and Saint-Jules clastic rocks, as well as the massive groundwater calcretes, occurred prior to deposition of the Bonaventure Formation. Like the La Coulée and Bonaventure formations, the Saint-Jules is undated, but unconformably overlies Acadian structures (Middle Devonian) and predates Mabou Group units (Namurian).

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.

Tracking dinosaurs in BLM canyon country, Utah

2018 ◽  
Vol 3 ◽  
pp. 67-100 ◽  
Author(s):  
ReBecca K. Hunt-Foster ◽  
Martin G. Lockley ◽  
Andrew R.C. Milner ◽  
John R. Foster ◽  
Neffra A. Matthews ◽  
...  
Keyword(s):  
Colorado Plateau ◽  
Foreland Basin ◽  
Salt Tectonics ◽  
Initial Development ◽  
Paradox Basin ◽  
Cedar Mountain Formation ◽  
History Of ◽  
San Rafael ◽  
San Rafael Swell ◽  
Biological History

Although only recognized as a discrete stratigraphic unit since 1944, the Cedar Mountain Formation represents tens of millions of years of geological and biological history on the central Colorado Plateau. This field guide represents an attempt to pull together the results of recent research on the lithostratigraphy, chronostratigraphy, sequence stratigraphy, chemostratigraphy, and biostratigraphy of these medial Mesozoic strata that document the dynamic and complex geological history of this region. Additionally, these data provide a framework by which to examine the history of terrestrial faunas during the final breakup of Pangaea. In fact, the medial Mesozoic faunal record of eastern Utah should be considered a keystone in understanding the history of life across the northern hemisphere. Following a period of erosion and sediment bypass spanning the Jurassic–Cretaceous boundary, sedimentation across the quiescent Colorado Plateau began during the Early Cretaceous. Thickening of these basal Cretaceous strata across the northern Paradox Basin indicate that salt tectonics may have been the predominant control on deposition in this region leading to the local preservation of fossiliferous strata, while sediment bypass continued elsewhere. Thickening of overlying Aptian strata west across the San Rafael Swell provides direct evidence of the earliest development of a foreland basin with Sevier thrusting that postdates geochemical evidence for the initial development of a rain shadow.

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