Lower Paleozoic stratigraphic and biostratigraphic correlations in the Canadian Cordillera: implications for the tectonic evolution of the Laurentian margin

2003 ◽  
Vol 40 (12) ◽  
pp. 1739-1753 ◽  
Author(s):  
Leanne J Pyle ◽  
Christopher R Barnes
Keyword(s):  
Tectonic Evolution ◽  
Passive Margin ◽  
Lower Paleozoic ◽  
Early Devonian ◽  
Southern Rocky Mountains ◽  
Peace River ◽  
Regional Correlation ◽  
Laurentian Margin ◽  
Peace River Arch ◽  
Early Late

The ancient Laurentian margin rifted in the latest Neoproterozoic to early Cambrian but appears not to have developed as a simple passive margin through a long, post-rift, drift phase. Stratigraphic and conodont biostratigraphic information from four platform-to-basin transects across the margin has advanced our knowledge of the early Paleozoic evolution of the margin. In northeastern British Columbia, two northern transects span the Macdonald Platform to Kechika Trough and Ospika Embayment, and a third transect spans the parautochthonous Cassiar Terrane. In the southern Rocky Mountains, new conodont biostratigraphic data for the Ordovician succession of the Bow Platform is correlated to coeval basinal facies of the White River Trough. In total, from 26 stratigraphic sections, over 25 km of strata were measured and > 1200 conodont samples were collected that yielded over 100 000 conodont elements. Key zonal species were used for regional correlation of uppermost Cambrian to Middle Devonian strata along the Cordillera. The biostratigraphy temporally constrains at least two periods of renewed extension along the margin, in the latest Cambrian and late Early Ordovician. Alkalic volcanics associated with abrupt facies changes across the ancient shelf break, intervals of slope debris breccia deposits, and distal turbidite flows suggest the margin was characterized by intervals of volcanism, basin foundering, and platform flooding. Siliciclastics in the succession were sourced by a reactivation of tectonic highs, such as the Peace River Arch. Prominent hiatuses punctuate the succession, including unconformities of early Late Ordovician, sub-Llandovery, possibly Early to Middle Silurian and Early Devonian ages.

Tectonic evolution and significance of Silurian – Early Devonian hinterland-directed deformation in the internal Humber zone of the southern Quebec Appalachians

2003 ◽  
Vol 40 (2) ◽  
pp. 255-268 ◽  
Author(s):  
Sébastien Castonguay ◽  
Alain Tremblay
Keyword(s):  
New England ◽  
Tectonic Evolution ◽  
Normal Faults ◽  
Early Devonian ◽  
Middle Ordovician ◽  
Tectonic History ◽  
History Of ◽  
Connecticut Valley ◽  
Laurentian Margin ◽  
Nappe Emplacement

In the southern Quebec Appalachians, the early tectonic history of the Laurentian margin (Humber zone) comprises foreland-propagating, northwest-directed thrust faulting, nappe emplacement, and regional prograde metamorphism in response to the obduction of large ophiolitic nappes during the Taconian orogeny. In the internal Humber zone, this event is dated at 462 ± 3 Ma (late Middle Ordovician), which is interpreted to represent the timing of near-peak Taconian metamorphism. Superimposed hinterland-directed structures are accompanied by retrograde metamorphism and consist of back thrusts and normal faults, which respectively delimit the northwestern and southeastern limbs of the Sutton and Notre-Dame mountains anticlinoria, both salient structures of the internal Humber zone of southern Quebec. Geochronologic data on the timing of hinterland-directed deformation vary from 431 to 411 Ma. Two tectonic models are presented and discussed, which may account for the Silurian – Early Devonian evolution of the Laurentian margin: (1) back thrusting and syn- to post-compressional crustal extension in response to the tectonic wedging of basement-cored duplexes inducing delamination of supracrustal rocks; (2) tectonic exhumation of the internal Humber zone by extensional collapse. Evidence for Silurian – Early Devonian extensional tectonism in the Humber zone provides the basement infrastructures necessary for the creation and the onset of sedimentation in the Gaspé Belt basins (e.g., Connecticut Valley – Gaspé synclinorium). Several structural, metamorphic features in the internal Humber zone of the northwestern New England Appalachians yield analogous characteristics with those of southern Quebec and may have shared a similar Silurian – Early Devonian tectonic evolution.

Evolution of the early Paleozoic Cordilleran margin of Laurentia: tectonic and eustatic events interpreted from sequence stratigraphy and conodont community patterns

2005 ◽  
Vol 42 (6) ◽  
pp. 999-1031 ◽  
Author(s):  
Shunxin Zhang ◽  
Leanne J Pyle ◽  
Christopher R Barnes
Keyword(s):  
Sea Level ◽  
Sequence Stratigraphy ◽  
Passive Margin ◽  
Early Paleozoic ◽  
Relative Sea Level ◽  
Lower Paleozoic ◽  
Community Patterns ◽  
Regional Tectonic ◽  
Laurentian Margin ◽  
Cordilleran Margin

Several field seasons in the Canadian Cordillera have allowed the measurement, description and sampling of over 20 000 m of lower Paleozoic strata from 26 stratigraphic sections across four platform-to-basin transects, with the recovery of over 100 000 conodonts from more than 1200 4–5 kg samples. This work was part of the Lithoprobe Slave – Northern Cordillera Lithospheric Evolution (SNORCLE) project but is also being extended through a Pan-Lithoprobe project to understand the tectonic and eustatic response of much of the Laurentian plate through the early Paleozoic. Based on the abundant field data, the complex stratigraphic framework is interpreted in terms of sequence stratigraphy and a derived relative sea-level curve. Using detailed conodont taxonomic and biostratigraphic results, cluster analysis of conodont distributional data identified an evolving series of conodont communities through space and time. These communities were partitioned across the platform-to-basin gradient and provide an additional sensitive indicator of relative sea-level change. These two independent approaches generated comparable eustatic curves for this Cordilleran Laurentian margin during much of the early Paleozoic and identified some global eustatic events noted by earlier workers. This part of Laurentia was not a simple passive margin during the early Paleozoic, but rather was affected by four main tectonic events complicated by six principal eustatic changes. Some success was achieved in filtering the global and regional tectonic–eustatic effects and in proposing causes for some of the events.

An early Late Cretaceous (Cenomanian) sturgeon (Acipenseriformes) from the Dunvegan Formation, northwestern Alberta, Canada

2014 ◽  
Vol 51 (7) ◽  
pp. 677-681 ◽  
Author(s):  
Matthew J. Vavrek ◽  
Alison M. Murray ◽  
Phil R. Bell
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Recent Survey ◽  
Peace River ◽  
Northern Regions ◽  
Early Late

A recent survey of the middle Cenomanian Dunvegan Formation along the Peace River, Alberta, has yielded a partial skull of a large acipenseriform fish. The fossil was from an animal approximately 5 m in length, based on comparisons with living relatives. Though incomplete, this represents an important record of mid-Cretaceous fish from northern North America, as formations of this age are virtually unexplored in northern regions. This fossil is the oldest acipenserid from North America, and one of the most northerly known.

Present and Past Geothermal Regimes and Source Rock Maturation, Peace River Arch Area, Canada (1)

AAPG Bulletin ◽  
1992 ◽  
Vol 76 ◽  
Author(s):  
STEFAN BACHU (2) and SONG CAO (3)
Keyword(s):  
Source Rock ◽  
Peace River ◽  
Peace River Arch

scholarly journals Overview of Cordilleran oceanic terranes and their significance for the tectonic evolution of the northern Cordillera

2021 ◽  
Author(s):  
A Zagorevski ◽  
C R van Staal ◽  
J H Bédard ◽  
A Bogatu ◽  
D Canil ◽  
...  
Keyword(s):  
Continental Margin ◽  
Tectonic Evolution ◽  
Middle Triassic ◽  
Passive Margin ◽  
Suprasubduction Zone ◽  
Ophiolitic Rocks ◽  
Juvenile Crust ◽  
Tectonic Framework ◽  
Tectonic Reconstructions ◽  
Stratigraphic Nomenclature

Ophiolite complexes are an important component of oceanic terranes in the northern Cordillera and constitute a significant amount of juvenile crust added to the Mesozoic Laurentian continental margin during Cordilleran orogenesis. Despite their tectonic importance, few systematic studies of these complexes have been conducted. Detailed studies of the pseudostratigraphy, age, geochemistry, and structural setting of ophiolitic rocks in the northern Cordillera indicate that ophiolites formed in Permian to Middle Triassic suprasubduction zone settings and were obducted onto passive margin sequences. Re-evaluation of ophiolite complexes highlights fundamental gaps in the understanding of the tectonic framework of the northern Cordillera. The previous inclusion of ophiolite complexes into generic 'oceanic' terranes resulted in significant challenges for stratigraphic nomenclature, led to incorrect terrane definitions, and resulted in flawed tectonic reconstructions.

Peace River Arch of Western Canada: ABSTRACT

AAPG Bulletin ◽  
1964 ◽  
Vol 48 ◽  
Author(s):  
George de Mille
Keyword(s):  
Western Canada ◽  
Peace River ◽  
Peace River Arch

Peace River Arch: ABSTRACT

AAPG Bulletin ◽  
1964 ◽  
Vol 48 ◽  
Author(s):  
George de Mille
Keyword(s):  
Peace River ◽  
Peace River Arch

Évolution paléogéographique de la marge nord-ouest de l'Afrique du Cambrien à la fin du Carbonifère (du Maroc au Libéria)

1991 ◽  
Vol 28 (7) ◽  
pp. 1121-1130 ◽  
Author(s):  
Michel Villeneuve ◽  
Jean-Jacques Cornée
Keyword(s):  
West African ◽  
The West ◽  
Lower Paleozoic ◽  
West African Craton ◽  
Middle Cambrian ◽  
Early Devonian ◽  
Middle Ordovician ◽  
The North ◽  
Marine Platform ◽  
General Regression

Paleogeographic reconstructions of Paleozoic time are presented for the northwest margin of the West-African Craton. An extensional regime and a marine transgression were dominant during the Early Cambrian. During the Middle Cambrian, the Rokélides orogen was responsible for the sea regression to the south, while the proto-Atlantic opening was active to the north of the Reguibat shield. A large stable marine platform was present during Early and Middle Ordovician. A general regression and the formation of the West-African Inlandsis took place during the Late Ordovician. During Silurian time, this sea transgressed over most of the African platform. Incipient Hercynian deformations during the Early Devonian produced horsts and grabens in Morocco. At the end of the Devonian and the beginning of the Carboniferous, the sea was restricted to isolated basins and tectonic trenches. Collision between West Africa and North America during the Late Carboniferous transformed the Lower Paleozoic margin into an Hercynian orogenic belt, whose structure is controlled by the presence of crustal blocks, generated as early as the Cambrian, and probably reflecting, in turn, older Panafrican zones of weakness. [Translated by the Journal]

The last pteraspids (Vertebrata, Heterostraci): new material from the Middle Devonian of Alberta and Idaho

2020 ◽  
Vol 94 (4) ◽  
pp. 758-772
Author(s):  
David K. Elliott ◽  
Linda S. Lassiter ◽  
Kathryn E. Geyer
Keyword(s):  
Middle Devonian ◽  
New Genus ◽  
New Combination ◽  
Additional Material ◽  
Lower Paleozoic ◽  
Early Devonian ◽  
Red Sandstone ◽  
Large Channel ◽  
New Material ◽  
Paleozoic Rocks

AbstractThis report documents the last pteraspids, (armored, jawless members of the Heterostraci), which are otherwise only known from the Early Devonian of the Old Red Sandstone Continent. Tuberculate pteraspid heterostracans are described from the Middle Devonian beds of two formations in western North America. The late Givetian Yahatinda Formation of Alberta and British Columbia consists of channels cut into lower Paleozoic rocks and represents deposition in marine to littoral environments. Clavulaspis finis (Elliott et al., 2000a) new combination is redescribed from additional material from the Yahatinda Formation and reassigned to the new genus Clavulaspis because the original genus name is invalid. The Eifelian Spring Mountain beds of Idaho consist of a large channel that represents a clastic-dominated estuarine environment. It contains Scutellaspis wilsoni new genus new species, and the previously described species from the Spring Mountain beds is redescribed and reassigned to Ecphymaspis new genus, which was prompted by new material and a review of the validity of the original genus name. Phylogenetic analysis shows that these three new taxa form part of the derived clade Protaspididae.UUID: http://zoobank.org/9cf09b21-cec1-4ce4-bc2b-658d0b515e10

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