scholarly journals Tectonic setting of Middle Devonian to Lower Carboniferous rocks in the Magdalen Basin

10.4138/2008 ◽  
1993 ◽  
Vol 29 (3) ◽  
Author(s):  
P. Durling ◽  
F. Marillier
Keyword(s):  
Middle Devonian ◽  
Tectonic Setting ◽  
Lower Carboniferous

Stratigraphic evolution of the Paleozoic Stikine assemblage in the Stikine and Iskut rivers area, northwestern British Columbia

1991 ◽  
Vol 28 (6) ◽  
pp. 958-972 ◽  
Author(s):  
Derek A. Brown ◽  
James M. Logan ◽  
Michael H. Gunning ◽  
Michael J. Orchard ◽  
Wayne E. Bamber
Keyword(s):  
Middle Devonian ◽  
Tectonic Setting ◽  
Volcanic Rocks ◽  
Upper Permian ◽  
Lower Permian ◽  
Early Permian ◽  
Lower Carboniferous ◽  
Modern Analogue ◽  
Arc Setting ◽  
Coralline Limestone

The Stikine assemblage, the "basement" of Stikinia, extends 500 km along the western flank of the Intermontane Belt, east of younger Coast Belt plutons. Four different stratigraphic successions are characteristic of Lower to Middle Devonian, Carboniferous and Permian rocks in the Stikine and Iskut rivers area. West of Forrest Kerr Creek are penetratively deformed Lower to Middle Devonian island-arc volcaniclastic rocks, coralline limestone, and felsic tuff. Fringing carbonate buildups in an arc setting are best illustrated in the sequence at Round Lake where Lower Carboniferous mafic-dominated, bimodal submarine volcanic rocks grade upward into two distinctive coarse echinoderm limestone units and medial siliceous siltstone and limestone conglomerate. Conodont colour alteration indices for Lower Carboniferous rocks near Newmont Lake indicate an anomalously low-temperature thermal history. Upper Carboniferous–Permian polymictic volcanic conglomerate and Lower Permian limestone overlie these strata there. The Scud River sequence is distinguished by subgreenschist- to greenschist-grade Carboniferous(?) volcanic and sedimentary rocks overlain by a structurally thickened package (greater than 1000 m) of Lower Permian limestone. Local calcalkaline pyroclastic rocks interfinger with limestone near the top of the Scud River sequence. Basinal, shelf, and shallow-water carbonate facies developed in the Early Permian, giving way to calcalkaline volcanism in Late Permian followed by deposition of deep-water chert and argillite.The tectonic setting during the Devonian and Carboniferous is comparable with modern Pacific volcanic arcs and atolls, but there is no modern analogue for the shelf-carbonate accumulation during the Early Permian which characterizes the Stikine assemblage and permits Cordilleran-scale correlations. Permian fusulinid and coral species have very close affinity to those of the McCloud Limestone of the eastern Klamath Mountains, California. Other geologic events common to both Stikinia and the Eastern Klamath terrane are Devonian limestone breccia deposition, Lower Permian limestone accumulation with McCloud faunal affinity, Carboniferous and Permian calcalkaline volcanism, and Upper Permian tuffaceous limestone. Stratigraphic differences include the absence of quartz detritus in Devonian strata and lack of thick Upper Permian volcanic rocks in the Stikine River area.

Petrogenesis and tectonic setting of the Middle Devonian Beitashan Formation volcanic rocks in the northern East Junggar, NW China: Insights from geochemistry, zircon U–Pb dating, and Hf isotopes

2020 ◽  
Vol 55 (3) ◽  
pp. 1964-1983 ◽  
Author(s):  
Qian Xu ◽  
Yongjun Li ◽  
Gaoxue Yang ◽  
Wentao Ning ◽  
Lili Tong ◽  
...  
Keyword(s):  
Middle Devonian ◽  
Tectonic Setting ◽  
Volcanic Rocks ◽  
Hf Isotopes ◽  
Nw China

Integrated analyses constraining the provenance of sandstones, mudstones, and conglomerates, a case study: the Laojunshan conglomerate, Qilian orogen, northwest China

2007 ◽  
Vol 44 (7) ◽  
pp. 961-986 ◽  
Author(s):  
Zhen Yan ◽  
Wenjiao Xiao ◽  
Zongqi Wang ◽  
Jilian Li
Keyword(s):  
Tibetan Plateau ◽  
Middle Devonian ◽  
Tectonic Setting ◽  
Active Continental Margin ◽  
Geochemical Data ◽  
The North ◽  
Northern Tibetan Plateau ◽  
Wide Range ◽  
Qilian Orogen ◽  
North Qilian

The Qilian orogenic belt in the northern Tibetan plateau connects the Altaids to the north with the Tethyan orogenic system to the south and occupies a key tectonic position in the evolution and assembly of Asia. The belt contains a wide range of subduction–accretion-related petrotectonic units. The Early–Middle Devonian Laojunshan conglomerate, deposited unconformably upon Cambrian–Silurian strata along the northern margin of the North Qilian terrane, contains a record of the late Paleozoic tectonism of the Qilian orogen. Its provenance and tectonic setting are critical in understanding not only the tectonic evolution of Tibetan plateau, but Paleozoic global reconstructions as well. The composition of clastic conglomerates and heavy mineral assemblages of sandstones suggests that coeval mafic, felsic, metamorphic, and sedimentary rocks were the main sources. The geochemistry of volcanic clasts and paleocurrent and paleogeographic data suggest derivation from subduction–accretion complexes in the North Qilian terrane. The geochemistry of siltstones and mudstones indicates that the Laojunshan conglomerate was derived from an arc and accumulated in an active continental margin. Geochemical data of granitoid clasts suggest that they were derived from Ordovician–Silurian subduction-related magmatic rocks. Mafic and ultramafic clasts, chromite, and magnetite decrease upwards in the stratigraphy whereas metamorphic, sedimentary and granitoid clasts, and garnet increase. These data imply that mafic rocks were the predominant source during initial deposition. Regional studies suggest that the North China plate subducted southwards and produced subduction-related arc magmatism along the southern margin of the North Qilian terrane during the Early–Middle Devonian. Therefore, we interpret the Laojunshan conglomerate as a fore-arc basin fill.

Petrography and geochemistry of lower carboniferous greywacke and mudstones in Northeast Junggar, China: Implications for provenance, source weathering, and tectonic setting

2014 ◽  
Vol 87 ◽  
pp. 11-25 ◽  
Author(s):  
Huifei Tao ◽  
Shu Sun ◽  
Qingchen Wang ◽  
Xiaofa Yang ◽  
Lin Jiang
Keyword(s):  
Tectonic Setting ◽  
Lower Carboniferous

Deformation history in part of the Lubec–Belleisle zone of southern New Brunswick

1970 ◽  
Vol 7 (3) ◽  
pp. 748-767 ◽  
Author(s):  
R. L. Brown ◽  
H. Helmstaedt
Keyword(s):  
New Brunswick ◽  
Middle Devonian ◽  
Maximum Principal Stress ◽  
Upper Devonian ◽  
Second Phase ◽  
Lower Carboniferous ◽  
The North ◽  
Principal Compressive Stress ◽  
Two Phases ◽  
Paleozoic Rocks

Rocks of the Proterozoic Coldbrook Group on the north shore of the Bay of Fundy, New Brunswick, are bounded to the north by a major northeast trending fault (Lubec–Belleisle). North of the fault Paleozoic rocks of the Mascarene Group are overlain unconformably by Upper Devonian and Lower Carboniferous strata.Both the Coldbrook and Mascarene Groups have been deformed by three phases of deformation. Deformation of the two Groups was coeval; penetrative fabrics first developed during the Acadian (Middle Devonian) orogeny.Pre-Acadian Paleozoic movements were limited to local or regional uplift with possible attendant warping and/or gentle tilting.Mylonitic fabrics formed in Coldbrook rocks during the first two phases of the Acadian polyphase deformation. These northeast trending s- surfaces lie normal to the direction of maximum finite shortening. Also from the orientation of synmylonization quartz deformation lamellae of the second phase, it is apparent that the local trajectory of the maximum principal stress was normal to the s-surfaces of the mylonites.No evidence for major northeast–southwest strike slip faulting has been found. Fracture analyses in Upper Devonian and Lower Carboniferous rocks in the northeast trending fault zone, point to a northwest trending principal compressive stress.It is contended that the bulk of the ductile strain (first two phases) occurred In response to northwest principal compressive stress during the Middle Devonian, and these stresses were re-established in post-Devonian times, resulting in the development of high angle oblique to dip slip movements on the northeast trending faults.

scholarly journals Geochemistry of the Lower Carboniferous mudrocks in the Dulate arc, northeastern Junggar, China: Implications for paleoweathering, provenance and tectonic setting

2018 ◽  
Vol 52 (4) ◽  
pp. 299-316
Author(s):  
Huifei Tao ◽  
Zhen Qiu ◽  
Hongjie Ji ◽  
Junli Qiu
Keyword(s):  
Tectonic Setting ◽  
Lower Carboniferous

Upper Devonian miospores from the Escuminac Formation, eastern Québec, Canada

1970 ◽  
Vol 7 (1) ◽  
pp. 29-45 ◽  
Author(s):  
Wayne W. Brideaux ◽  
Norman W. Radforth
Keyword(s):  
Middle Devonian ◽  
Russian Platform ◽  
Upper Devonian ◽  
New Combinations ◽  
Lower Carboniferous ◽  
The Third ◽  
Large Size ◽  
Assem Blages ◽  
Small Spore ◽  
Orcadian Basin

Miospores of early Frasnian age are described from the third unit of the Escuminac Formation in eastern Québec, Canada. The assemblage comprises 34 species, including 8 species proposed as new, 2 new combinations, and 12 sparsely represented forms not considered synonymous with previously described species.The assemblage is most closely comparable to a Middle Devonian assemblage from the Orcadian Basin, Scotland. Similarities are also noted with European and Russian assemblages, particularly from the Eifelian–Givetian of the Russian Platform. Except for five long-ranging species, elements of Lower Carboniferous assemblages are lacking. Evidence suggests a transitional nature for this Escuminac assemblage. Miospores of relatively large size, a feature of Middle Devonian assemblages, are present. Marked differentiation of large and small spore types, found in several other Upper Devonian assem blages is absent. Apiculate and anchor-spined species dominate the Escuminac assemblage.

Petrogenesis and tectonic setting of Late Devonian high-Mg andesites in the Beishan orogen, NW China

2021 ◽  
pp. 1-16
Author(s):  
Guo-Qiang Wang ◽  
Xiang-Min Li ◽  
Ji-Yuan Yu ◽  
Tao Bu ◽  
Bo-Tao Huang ◽  
...  
Keyword(s):  
Middle Devonian ◽  
Plate Tectonics ◽  
Tectonic Setting ◽  
Late Devonian ◽  
Nd Isotope ◽  
Central Asian ◽  
Mantle Peridotites ◽  
Regional Tectonic ◽  
Southern Central ◽  
Early Late

Abstract High-Mg andesites (HMAs) are crucial for the reconstruction of plate tectonics, continental margin formation and lithospheric evolution. In this study, we present new fossil age, whole-rock geochemical and Sr–Nd isotope data on the newly discovered Dundunshan Group HMAs in the Dundunshan area of the Beishan orogen (central-southern Central Asian Orogenic Belt). The Dundunshan HMA samples are characterized by high MgO (6.47–7.02 wt%) contents and high Mg# values (67.27–68.77), with SiO2 (58.57–62.13 wt%), Al2O3 (14.49–16.07 wt%) and CaO (5.05–6.24 wt%) resembling typical HMAs. The Dundunshan HMA samples are calc-alkaline and strongly enriched in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs), with slightly negative Eu anomaly and high-field-strength element (HFSE) depletions. Their (87Sr/86Sr)i ratios (0.7041–0.7057) and ϵNd(t) (3.73–5.59) indicate that the Dundunshan HMAs were mainly formed by the interactions between subducted oceanic sediment-derived melts and mantle peridotites. Fossil evidence and published radiometric age data constrain the formation of the Dundunshan HMAs to early Late Devonian time. Sedimentological features of the Middle Devonian Sangejing Formation and regional tectonic correlation suggest that the Hongliuhe–Niujuanzi–Xichangjing Ocean in the Dundunshan area was likely closed during late Middle Devonian time, and that the Dundunshan HMAs were formed in a post-collision extensional setting.

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