Early Ordovician to Early Devonian tectonic development of the northern margin of Laurentia, Canadian Arctic Islands

2019 ◽  
Vol 131 (7-8) ◽  
pp. 1075-1094 ◽  
Author(s):  
Keith Dewing ◽  
Thomas Hadlari ◽  
D. Graham Pearson ◽  
William Matthews
Keyword(s):  
Canadian Arctic ◽  
Early Devonian ◽  
Northern Margin ◽  
Early Ordovician ◽  
Tectonic Development

scholarly journals The Wandel Valley Formation (Early - Middle Ordovician) of North Greenland and its correlatives

1988 ◽  
Vol 137 ◽  
pp. 61-92
Author(s):  
J.S Peel ◽  
M.P Smith
Keyword(s):  
Canadian Arctic ◽  
East Greenland ◽  
Middle Ordovician ◽  
Early Ordovician ◽  
Lowermost Part ◽  
North Greenland

Members are formally described within the Wandel Valley Formation (Early - Middle Ordovician) of the Ryder Gletscher Group in central and eastem North Greenland. In Peary Land the names Pyramideplateau Member (the combined lower and middle informal members of previous usage) and Vestervig Elv Member (the upper member) are proposed. In Kronprins Christian Land, the Alexandrine Bjerge Member (new) overlies the previously named Danmarks Fjord and Amdrup Members. Conodont studies, supported by the macrofauna, indicate that the Pyramideplateau, Danmarks Fjord and Amdrup Members are of late Canadian (Early Ordovician) age. The Canadian-Whiterockian boundary lies within the lowermost part of the Vestervig Elv and Alexandrine Bjerge Members. The top of the former is of earliest Late Whiterockian age while the Alexandrine Bjerge Member only extends into the late Middle Whiterockian. The members of the Wandel Valley Formation are correlated with coeval successions in western North Greenland, East Greenland, the Canadian Arctic Islands and Svalbard.

Composition, structure and tectonic analysis of the Shangrimuce arc-continent collision zone on the northern margin of the Central Qilian, NW China

2021 ◽  
Author(s):  
Hongyuan Zhang ◽  
Zhibin Lei ◽  
Bo Yang ◽  
Qing Liu ◽  
Haijun Zhang ◽  
...  
Keyword(s):  
Shear Zones ◽  
Oceanic Lithosphere ◽  
Late Ordovician ◽  
Island Arc ◽  
Qilian Mountain ◽  
Northern Margin ◽  
Early Ordovician ◽  
Collision Zone ◽  
Two Stages ◽  
Back Arc

<p>A 1:50000 regional survey, covering an area of about 2000 km<sup>2</sup>, was carried out in the Shangrimuce area of Qilian Mountain in Northwest China. The results show that during Caledonian, the northern margin of the Central Qilian block experienced collision with mature island arcs and subsequently northward expansion. In the Shangrimuce study area, five geological units have been identified; they are, form south to north, back-arc basin, early Ordovician island arc, inter arc basin, middle Late Ordovician island arc, and fore-arc and oceanic lithosphere amalgamation zone. </p><p>(1) back-arc basin. In the Yangyuchi- Shule River- Cuorigang- Wawusi area, there may be a back-arc spreading basin, and there should be spreading basins in this area. It is speculated that there was a northward reverse subduction in the late Ordovician, accompanied by a syenite body, a broad spectrum dyke swarms and an accretionary wedge zone in the whole area.</p><p>(2) early Ordovician island arc. In the Shangrimuce-Dander area, the Proterozoic basement granitic gneiss, the early Ordovician island arc block and the high-pressure geological body all occur in the form of thrust horses, forming a double metamorphic belt, which reveals the existence of ocean subduction to south in the early Ordovician. </p><p>(3) inter arc basin. On both banks of Tuolai River to the east of Yanglong Township, there are early Middle Ordovician inter-arc basins with oceanic crust. </p><p>(4) middle Late Ordovician island arc. To the north of Tuolai River, there is a middle Late Ordovician island arc belt. Both sides of the island arc zone experienced strong ductile shear deformation, which recorded a complex arc-continent collision. </p><p>(5) fore-arc and oceanic lithosphere amalgamation zone (Fig.1). The Yushigou area has developed a fore-arc and oceanic lithospheric amalgamation zone, with weakly deformed fore-arc flysch basin, strongly deformed siliceous rocks, pillow Basalt, diabase, gabbro, peridotite and other rock assemblages.</p><p>Combined with the characteristics of arc-continent collision zone in the Western Pacific, there are two stages of shear zone series (Fig.2). One is ductile shear zones formed by the South dipping gneissic belt, revealing the existence of oceanic subduction accretion wedge and emplacement of high-pressure rocks. Another superimposed one is north dipping. This indicates that the arc-continent collision caused by back-arc reverse subduction, which ultimately controls the overall geometric and kinematic characteristics of the shear zones in the region.</p><p><img src="https://contentmanager.copernicus.org/fileStorageProxy.php?f=gepj.8219836ca50067454890161/sdaolpUECMynit/12UGE&app=m&a=0&c=40b3389c641f2d0ca723e1527c32927e&ct=x&pn=gepj.elif&d=1" alt=""></p><p>Figure 1 United sections showing a Caledonian trench-arc system in the Qilian Mountain, NW China.</p><p><img src="https://contentmanager.copernicus.org/fileStorageProxy.php?f=gepj.8def566da50066084890161/sdaolpUECMynit/12UGE&app=m&a=0&c=e82258ecc235c4e618abd6c035b58232&ct=x&pn=gepj.elif&d=1" alt=""></p><p>Figure 2 Structural analysis at Hongyahuo, indicating two stages of deformation.</p><p>The research has been supported by projects from the Ministry of Land and Resources (No.201211024-04; 1212011121188) and the 2020 undergraduate class construction project from China University of Geosciences (Beijing) (No. HHSKE202003).</p><p> </p>

The Boothiaspidinae, a new agnathan subfamily (Heterostraci, Cyathaspididae) from the late Silurian and Early Devonian of the western United States and the Canadian Arctic

2016 ◽  
Vol 90 (6) ◽  
pp. 1212-1224
Author(s):  
David K. Elliott
Keyword(s):  
United States ◽  
New Genus ◽  
Canadian Arctic ◽  
Western United States ◽  
Early Devonian ◽  
Previous Evidence ◽  
Red Sandstone ◽  
The Family ◽  
Close Relationship ◽  
Three New Species

AbstractThree new species of the new genus Phyllonaspis are described from Early Devonian localities in the western United States. Phyllonaspis laevis, P. serratus, and P. taphensis are broad, flattened cyathaspids with lateral brims and fine dermal ornament, that show a close relationship to the cyathaspids Boothiaspis and Alainaspis from the late Silurian and Early Devonian of the Canadian Arctic. These taxa are here accommodated within the new subfamily Boothiaspidinae within the family Cyathaspididae. This relationship supports previous evidence of faunal connection between these two areas and indicates dispersal around the Old Red Sandstone Continent from a center in the Canadian Arctic. Isolated oral plates allow a reconstruction of the oral cover and increase our knowledge of the range of oral structures in this family.

New species of the cyathaspididPoraspis(Agnatha: Heterostraci) from the Late Silurian and Early Devonian of Northwest Territories, Canada

1998 ◽  
Vol 72 (2) ◽  
pp. 360-370 ◽  
Author(s):  
David K. Elliott ◽  
Elizabeth J. Loeffler ◽  
Yuhai Liu
Keyword(s):  
New Species ◽  
Eastern Europe ◽  
Northwest Territories ◽  
Canadian Arctic ◽  
Geographic Range ◽  
Center Of Origin ◽  
Early Devonian

Four new species of cyathaspidid extend the range of the genusPoraspisback into the Late Silurian and indicate that the Canadian arctic was its center of origin.Poraspis heintzaen. sp., P. cracens n. sp.,P. thulesn. sp. andP. parmulan. sp. also increase the known geographic range of the genus which had previously been reported only from the District of Mackenzie (NWT, Canada), Spitsbergen, western and eastern Europe. The identification ofP. sericeafrom the upper member of the Peel Sound Formation substantiates correlation of this interval with thecrouchizone of the Anglo-Welsh Borders, and provides another rare example of a species common to the Canadian arctic and European successions.

The Early Devonian (Pragian) zosterophyll Bathurstia denticulata Hueber

2000 ◽  
Vol 78 (2) ◽  
pp. 193-207 ◽  
Author(s):  
Michele E Kotyk ◽  
James F Basinger
Keyword(s):  
Phylogenetic Relationships ◽  
Lower Devonian ◽  
Canadian Arctic ◽  
Land Plants ◽  
Canadian Arctic Archipelago ◽  
Large Collection ◽  
Early Devonian ◽  
Northern Canada ◽  
Early Land

Approximately 86 specimens of Bathurstia denticulata Hueber were collected from upper Bathurst Island and lower Stuart Bay beds of Bathurst Island, Canadian Arctic Archipelago. Bathurstia was a component of a zosterophyll-dominated flora of Pragian age (Lower Devonian) that existed at low paleolatitudes in northern Canada. The large collection of well-preserved materials permits reconstruction of the plant as a robust scrambler of about 30 cm in height. Stems bear short, shelf-like emergences in two rows, and branch isotomously, although sparsely. Rooting organs, representing some of the oldest known for land plants, arise from the main aerial axes, although they are also associated with small, subordinate shoots interpreted as plantlets. Numerous specimens are fertile, with sporangia borne in dense terminal spikes. Spikes include two rows of overlapping, discoid sporangia. Isospores are round and featureless, and assignable to the genus Calamospora. While Bathurstia apparently originated from among the isotomously branching bilaterally symmetrical zosterophylls, the phylogenetic relationships of Bathurstia to known taxa is unclear, although some resemblance to Serrulacaulis, Barinophytaceae, and the Gosslingiaceae can be documented. Bathurstia denticulata is now one of the best known of early land plants, and contributes significantly to our understanding of zosterophylls and their role in Early Devonian vegetation.Key words: Bathurstia, zosterophyll, Devonian, Canada, Arctic, evolution.

Early Devonian eurypterids from the Northwest Territories of Arctic Canada

2000 ◽  
Vol 37 (8) ◽  
pp. 1167-1175 ◽  
Author(s):  
Simon J Braddy ◽  
Jason A Dunlop
Keyword(s):  
Northwest Territories ◽  
Marine Environment ◽  
Plant Material ◽  
Canadian Arctic ◽  
Arctic Canada ◽  
Early Devonian ◽  
Rock Formation

A new eurypterid fauna from the Lower Bear Rock Formation (Early Devonian, Emsian) of Anderson River, in the Northwest Territories of the Canadian Arctic, is described. The material comprises an almost complete specimen and five isolated carapaces of Erieopterus microphthalmus; an incomplete carapace and telson referred to Drepanopterus sp.; and an isolated prosomal appendage of Carcinosoma sp. Associations include actinopterygian, sarcopterygian, and acanthodian fish, as well as lingulids, conchostracans, ostracodes, coprolites, and plant material. A nearshore marine environment is inferred. This assemblage provides the first Canadian record of Drepanopterus and the youngest Canadian occurrences of erieopterid and carcinosomatid eurypterids.

scholarly journals Furongian (Jiangshanian) occurrences of radiodonts in Poland and South China and the fossil record of the Hurdiidae

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11800
Author(s):  
Xuejian Zhu ◽  
Rudy Lerosey-Aubril ◽  
Javier Ortega-Hernández
Keyword(s):  
South China ◽  
Fossil Record ◽  
Marine Ecosystems ◽  
Middle Cambrian ◽  
Early Devonian ◽  
Early Ordovician ◽  
Marine Life ◽  
Oral Cone ◽  
The Family ◽  
Sandstone Formation

The Furongian period represents an important gap in the fossil record of most groups of non-biomineralizing organisms, owing to a scarcity of Konservat-Lagerstätten of that age. The most significant of these deposits, the Jiangshanian strata of the Sandu Formation near Guole Township (Guangxi, South China), have yielded a moderately abundant, but taxonomically diverse soft-bodied fossil assemblage, which provides rare insights into the evolution of marine life at that time. In this contribution, we report the first discovery of a radiodont fossil from the Guole Konservat-Lagerstätte. The specimen is an incomplete frontal appendage of a possibly new representative of the family Hurdiidae. It is tentatively interpreted as composed of seven podomeres, six of which bearing laminiform endites. The best preserved of these endites is especially long, and it bears short auxiliary spines that greatly vary in size. This is the second occurrence of hurdiids and more generally radiodonts in the Furongian, the first being the external mould of an oral cone from Jiangshanian strata of the Wiśniówka Sandstone Formation in Poland. Restudy of this Polish specimen confirms that it belongs to a hurdiid radiodont and best compares to Peytoia. The family Hurdiidae includes the oldest (basal Cambrian Epoch 2) and youngest (Early Ordovician, possibly Early Devonian) representatives of the Radiodonta and as such, has the longest stratigraphical range of the group. Yet, hurdiids only became prominent components of marine ecosystems during the middle Cambrian (Miaolingian), and their fossil record in younger strata remains limited.

The ichnofauna of the Skiddaw Group (early Ordovician) of the Lake District, England

1996 ◽  
Vol 133 (2) ◽  
pp. 193-216 ◽  
Author(s):  
Patrick J. Orr
Keyword(s):  
Marine Environment ◽  
Lake District ◽  
Northern Margin ◽  
Early Ordovician ◽  
Marine Strata ◽  
High Diversity

AbstractDeep-marine strata of the Skiddaw Group, deposited in high southerly palaeolatitudes on the northern margin of Eastern Avalonia in the early Ordovician, contain a diverse ichnofauna dominated by examples of fodinichnia. This includes Alcyonidiopsis pharmaceus, several ichnospecies of Chondrites, Dictyodora zimmermani, Glockerichnus radiatus, Gordia marina, Ixalichnus enodius, two or possibly three ichnospecies of Phycodes, Planolites montanus, Volkichnium volki, an ‘arthropod-produced? repichnion’, ‘paired pits’, ?Gordia aff. marina, ‘thinly-walled, looping, burrows’ and burrows of Planolites/Palaeophycus affinity. Stellascolites radiatus Etheridge, 1876 is reassigned to the ichnogenus Glockerichnus Pickerill, 1982 as Glockerichnus radiatus (Etheridge, 1876).Several of the ichnotaxa are present in other ichnofaunal assemblages of early Ordovician age which were also emplaced at high southerly palaeolatitudes. The relatively high diversity of this ichnofaunal assemblage supports suggestions that models of the rate at which the deep-marine environment was colonized during the early Phanerozoic are in need of revision.

Structure of the Dingle Peninsula, SW Ireland: evidence for the nature and timing of Caledonian, Acadian and Variscan tectonics

2014 ◽  
Vol 152 (2) ◽  
pp. 242-268 ◽  
Author(s):  
S.P. Todd
Keyword(s):  
Deep Water ◽  
Volcanic Rocks ◽  
Fault Zones ◽  
Early Devonian ◽  
Shallow Marine ◽  
Red Sandstone ◽  
Early Ordovician ◽  
The North ◽  
Tectonic History ◽  
Extensional Structures

AbstractThe Palaeozoic rocks of the Dingle Peninsula provide a record of the evolution of the Caledonides, Acadides and Variscides. The succession ranges from Early Ordovician deep-water sediments, through Silurian shallow marine to non-marine sediments and volcanic rocks to an Old Red Sandstone (ORS) succession topped by Carboniferous marine shales. Comparison of structural styles in the unconformity-bounded groups, together with a detailed analysis of fault zones, allows the tectonic history to be deduced. The older rocks record Caledonian processes on the margin of Avalonia during Early Ordovician time and convergence then soft collision with Laurentia during Silurian time. The Dingle Basin was developed during the late Silurian – Early Devonian transtension in the Iapetus suture zone and was inverted in the latest Emsian Acadian orogenic episode. Post-Dingle Group ORS groups in the north of the peninsula were deposited in a syn-rift footwall block to the main Munster Basin. The Acadian transpressional and Munster Basin extensional structures were reactivated or overprinted in the Variscan deformation such that Acadian folds are transected by Variscan cleavage in both plan and vertical views. After Iapetus closure, changes in the tectonic regime are believed to be a result of adjustments in the geometry of subduction of the Rheic Ocean.

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