scholarly journals Early Ediacaran Magmatism in the Yenisei Ridge and Evolution of the Southwestern Margin of the Siberian Craton

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 565 ◽  
Author(s):  
Antonina Vernikovskaya ◽  
Valery A. Vernikovsky ◽  
Nikolay Matushkin ◽  
Pavel Kadilnikov ◽  
Dmitry V. Metelkin ◽  
...  
Keyword(s):  
Continental Margin ◽  
Siberian Craton ◽  
Time Window ◽  
Active Continental Margin ◽  
Yenisei Ridge ◽  
Crustal Material ◽  
Intermediate Composition ◽  
Southwestern Margin ◽  
Material Forming ◽  
Felsic Rocks

We present the first comprehensive data for the early Ediacaran stage of evolution of the western active continental margin of the Siberian Craton (Yenisei Ridge). U-Pb (SHRIMP-II SIMS) data for zircons from dikes of picrodolerites, quartz diorites, and leucocratic granites show that they were emplaced at 625 ± 5, 623 ± 8, and 626 ± 5 Ma, respectively, which indicates a narrow time window of Ediacaran magmatic events. The mafic tholeiitic rocks have OIB and E-MORB mantle components in their magmatic sources. Mineralogical and geochemical observations showed that the mantle-sourced mafic melts assimilated some crustal material, forming Th-enriched dikes of intermediate composition and K- and Rb-enriched felsic rocks. The possible geodynamic conditions for the formation of these early Ediacaran dikes are shown and a geodynamic model is presented for the development of the Yenisei Ridge orogen from the late Cryogenian to the late Ediacaran.

scholarly journals Dyke magmatism in the evolution of the transform active continental margin of the Siberian Craton in the Ediacaran

2019 ◽  
Vol 489 (3) ◽  
pp. 267-271
Author(s):  
A. E. Vernikovskaya ◽  
V. A. Vernikovsky ◽  
N. Yu. Matushkin ◽  
P. I. Kadilnikov ◽  
D. V. Metelkin ◽  
...  
Keyword(s):  
Continental Margin ◽  
Siberian Craton ◽  
Active Continental Margin ◽  
Quartz Diorite ◽  
Igneous Rocks ◽  
Yenisei Ridge ◽  
Isotope Data ◽  
Slab Breakoff ◽  
Work Up ◽  
First Time

An Ediacaran complex of dyke rocks has been identified for the first time in the Yenisei Ridge orogen. These igneous rocks are represented by basic, intermediate and acid variants and formed in the conditions of the transform active continental margin at the stages of its development before and during the interruption of subduction and slab breakoff: from dykes of the picrodolerite - ​dolerite-quartz diorite - leucogranite association with age in the range of 626-623 Ma (U-Th-U isotope data for zircons, SHRIMP-II method, this work) up to adakite - gabbro-anorthosite magmatism at the end of the Ediacaran.

The Paleomagnetic Pole of the Siberian Paleocontinent at the Late Ediacaran Stage of Evolution of the Active Continental Margin (South Yenisei Ridge)

2018 ◽  
Vol 483 (1) ◽  
pp. 1394-1398 ◽  
Author(s):  
P. I. Kadilnikov ◽  
A. E. Vernikovskaya ◽  
N. E. Mikhaltsov ◽  
V. A. Vernikovsky ◽  
N. Yu. Matushkin
Keyword(s):  
Continental Margin ◽  
Active Continental Margin ◽  
Yenisei Ridge ◽  
Paleomagnetic Pole

scholarly journals The first petrological evidence of subduction at the western margin of the Siberian сraton

2019 ◽  
Vol 484 (2) ◽  
pp. 209-214
Author(s):  
I, I, Likhanov ◽  
P. S. Kozlov ◽  
K. A. Savko ◽  
S. V. Zinoviev ◽  
A. A. Krylov
Keyword(s):  
High Pressure ◽  
Continental Margin ◽  
Siberian Craton ◽  
Early Stage ◽  
Yenisei Ridge ◽  
Paleoasian Ocean ◽  
Western Margin ◽  
History Of ◽  
Western Side ◽  
Two Stages

The discovery of relics of glaucophane schist in high-pressure tectonites of the suture zone of Yenisei Ridge has provided evidence for a Cordillera-type convergent boundary controlled by subduction of the oceanic crust beneath the continental margin on the western side of the Siberian Craton. According to the microtextural patterns of rocks and the results of geothermobarometry, two stages of metamorphism were distinguished. The formation of high-pressure tectonites indicates the early stage in the evolution of the Paleoasian Ocean and the final stage in the Neoproterozoic history of the Yenisei Ridge including completion of the accretion–subduction processes on the western margin of the Siberian Craton.

Dike Magmatism in the Evolution of the Transform Active Continental Margin of the Siberian Craton in the Ediacaran

2019 ◽  
Vol 489 (1) ◽  
pp. 1285-1288
Author(s):  
A. E. Vernikovskaya ◽  
V. A. Vernikovsky ◽  
N. Yu. Matushkin ◽  
P. I. Kadilnikov ◽  
D. V. Metelkin ◽  
...  
Keyword(s):  
Continental Margin ◽  
Siberian Craton ◽  
Active Continental Margin

Magmatism evolution and carbonatite-granite association in the neoproterozoic active continental margin of the Siberian craton: Thermochronological reconstructions

2013 ◽  
Vol 448 (2) ◽  
pp. 161-167 ◽  
Author(s):  
A. E. Vernikovskaya ◽  
V. M. Datsenko ◽  
V. A. Vernikovsky ◽  
N. Yu. Matushkin ◽  
Yu. M. Laevsky ◽  
...  
Keyword(s):  
Continental Margin ◽  
Siberian Craton ◽  
Active Continental Margin ◽  
Magmatism Evolution

scholarly journals Rheological Contrast between Quartz and Coesite Generates Strain Localization in Deeply Subducted Continental Crust

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 842
Author(s):  
Kouhei Asano ◽  
Katsuyoshi Michibayashi ◽  
Tomohiro Takebayashi
Keyword(s):  
Rheological Behavior ◽  
Strain Localization ◽  
Shear Zones ◽  
Ultrahigh Pressure ◽  
Ultramafic Rocks ◽  
Crustal Material ◽  
Orientation Data ◽  
Crystallographic Preferred Orientation ◽  
Dabie Shan ◽  
Felsic Rocks

Deformation microstructures of peak metamorphic conditions in ultrahigh-pressure (UHP) metamorphic rocks constrain the rheological behavior of deeply subducted crustal material within a subduction channel. However, studies of such rocks are limited by the overprinting effects of retrograde metamorphism during exhumation. Here, we present the deformation microstructures and crystallographic-preferred orientation data of minerals in UHP rocks from the Dabie–Shan to study the rheological behavior of deeply subducted continental material under UHP conditions. The studied samples preserve deformation microstructures that formed under UHP conditions and can be distinguished into two types: high-strain mafic–ultramafic samples (eclogite and garnet-clinopyroxenite) and low-strain felsic samples (jadeite quartzite). This distinction suggests that felsic rocks are less strained than mafic–ultramafic rocks under UHP conditions. We argue that the phase transition from quartz to coesite in the felsic rocks may explain the microstructural differences between the studied mafic–ultramafic and felsic rock samples. The presence of coesite, which has a higher strength than quartz, may result in an increase in the bulk strength of felsic rocks, leading to strain localization in nearby mafic–ultramafic rocks. The formation of shear zones associated with strain localization under HP/UHP conditions can induce the detachment of subducted crustal material from subducting lithosphere, which is a prerequisite for the exhumation of UHP rocks. These findings suggest that coesite has an important influence on the rheological behavior of crustal material that is subducted to coesite-stable depths.

Nature and origin of the volcanic ash beds near the Permian–Triassic boundary in South China: new data and their geological implications

2019 ◽  
Vol 157 (4) ◽  
pp. 677-689 ◽  
Author(s):  
Binsong Zheng ◽  
Chuanlong Mou ◽  
Renjie Zhou ◽  
Xiuping Wang ◽  
Zhaohui Xiao ◽  
...  
Keyword(s):  
Trace Element ◽  
Continental Margin ◽  
South China ◽  
Volcanic Ash ◽  
Active Continental Margin ◽  
Main Body ◽  
Early Triassic ◽  
Late Permian ◽  
Triassic Boundary ◽  
Permian Triassic Boundary

AbstractPermian–Triassic boundary (PTB) volcanic ash beds are widely distributed in South China and were proposed to have a connection with the PTB mass extinction and the assemblage of Pangea. However, their source and tectonic affinity have been highly debated. We present zircon U–Pb ages, trace-element and Hf isotopic data on three new-found PTB volcanic ash beds in the western Hubei area, South China. Laser ablation inductively coupled plasma mass spectrometry U–Pb dating of zircons yields ages of 252.2 ± 3.6 Ma, 251.6 ± 4.9 Ma and 250.4 ± 2.4 Ma for these three volcanic ash beds. Zircons of age c. 240–270 Ma zircons have negative εHf(t) values (–18.17 to –3.91) and Mesoproterozoic–Palaeoproterozoic two-stage Hf model ages (THf2) (1.33–2.23 Ga). Integrated with other PTB ash beds in South China, zircon trace-element signatures and Hf isotopes indicate that they were likely sourced from intermediate to felsic volcanic centres along the Simao–Indochina convergent continental margin. The Qinling convergent continental margin might be another possible source but needs further investigation. Our data support the model that strong convergent margin volcanism took place around South China during late Permian – Early Triassic time, especially in the Simao–Indochina active continental margin and possibly the Qinling active continental margin. These volcanisms overlap temporally with the PTB biocrisis triggered by the Siberian Large Igneous Province. In addition, our data argue that the South China Craton and the Simao–Indochina block had not been amalgamated with the main body of Pangea by late Permian – Early Triassic time.

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