Polycyclic Palaeozoic evolution of accretionary orogenic wedge in the southern Chinese Altai: Evidence from structural relationships and U–Pb geochronology

Broussolle, Arnaud; Aguilar, Carmen; Sun, Min; Schulmann, Karel; Štípská, Pavla; Jiang, Yingde; Yang, Yu; Xiao, Wenjiao; Wang, Sheng; Míková, Jitka

doi:10.1016/j.lithos.2018.06.005

Cited by 49 publications

(73 citation statements)

References 80 publications

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“…The correlation of magnetic and structural data shows that the magnetic highs reveal mainly a NW‐SE trend typical of Permian structures (Figures 11 and 12). In particular, the prominent and elongated magnetic high NW to SE of Altay city shows a good continuity at depth (Figures 6a and 8a) and correlates with a large‐scale Permian vertical and tabular deformation zone (Figures 12b and 12c) that is associated with extrusion of partially molten lower crust (Broussolle et al, 2018; Jiang et al, 2019). This deformation zone is composed of granulites and migmatites (Figure 13) where the decomposition of Fe‐rich biotite and the formation of magnetite imposed high magnetic susceptibility of these rocks (Martelat et al, 2014).…”

Section: Discussionmentioning

confidence: 88%

“…Synthesizing previous structural studies (Broussolle et al, 2018;Jiang et al, 2015;P. Li et al, 2015;P.…”

Section: Likely Sources Of Magnetic and Gravity Anomaliesmentioning

confidence: 85%

“…(b) Contacts between the Habahe Group and the Altai Formation, north of Altay city (modified from Jiang et al, 2019). (c) The Kalasu area and the Altai Formation (modified from Broussolle et al, 2018). (d) The Fuyun area and the Erqis Complex (modified from P. Li et al, 2017).…”

Section: Discussionmentioning

confidence: 99%

“…This general pattern can be interpreted in terms of terrane accretion, or, alternatively, it may have resulted from a Figure 2. Simplified geological map of the Chinese Altai and the East Junggar (modified from Broussolle et al, 2018;Liu et al, 2013) with terranes boundaries (thick dashed black curves) synthesized after Windley et al (2002) and Xiao et al (2004) and the different traces of the Erqis Zone from the literature (in red lines).…”

Section: 1029/2019tc006026mentioning

confidence: 99%

“…Tectonics Permian vertical and tabular deformation zone (Figures 12b and 12c) that is associated with extrusion of partially molten lower crust (Broussolle et al, 2018;Jiang et al, 2019). This deformation zone is composed of granulites and migmatites ( Figure 13) where the decomposition of Fe-rich biotite and the formation of magnetite imposed high magnetic susceptibility of these rocks (Martelat et al, 2014).…”

Section: 1029/2019tc006026mentioning

confidence: 99%

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Revision of the Chinese Altai‐East Junggar Terrane Accretion Model Based on Geophysical and Geological Constraints

et al. 2020

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Potential field data analysis, geology, and geochemistry are used to revise the terrane accretion model of the Chinese Altai and East Junggar. Major gradients of potential field data demarcate significant crustal structures and their continuity in depth. These data demonstrate that the distribution of geophysical anomalies does not match with terranes boundaries defined previously. Instead, heterogeneously developed NE/SW-trending gravity and NW-SE magnetic anomalies in both units correlate with Devonian and Permian tectonometamorphic zones, respectively. Geophysical data also indicate a dense lower crust of the East Junggar confirmed by previous igneous petrology studies and seismic experiment. The northern tip of this dense crust coincides with the main gravity gradient beneath the Chinese Altai and a prominent magnetic high located above a NW/SE-trending zone of Permian granulites. This zone forms a boundary between north-and south-dipping gravity and magnetic anomalies that are interpreted as reflecting quasi-symmetrical extrusion of the Chinese Altai crust. In contrast, all geophysical data show the absence of a prominent deep-seated discontinuity which can be correlated with the Erqis Zone. These data are compared with corresponding data sets from southern Mongolia allowing the proposition of a new geodynamic model for the studied area. This model involves (1) accretionary stage characterized by Late Devonian joint evolution of the East Junggar and Chinese Altai characterized by N-S trending orogenic fabrics and (2) Early Permian oroclinal bending associated with underthrusting of the dense Junggar basement beneath the Chinese Altai and the development of NW-SE trending deformation zones in both units.

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Section: Discussionmentioning

confidence: 88%

“…Synthesizing previous structural studies (Broussolle et al, 2018;Jiang et al, 2015;P. Li et al, 2015;P.…”

Section: Likely Sources Of Magnetic and Gravity Anomaliesmentioning

confidence: 85%

Section: Discussionmentioning

confidence: 99%

Section: 1029/2019tc006026mentioning

confidence: 99%

Section: 1029/2019tc006026mentioning

confidence: 99%

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Revision of the Chinese Altai‐East Junggar Terrane Accretion Model Based on Geophysical and Geological Constraints

et al. 2020

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Late Palaeozoic magmatism in the eastern Tseel Terrane of SW Mongolia evidenced by chronological and geochemical data

Hong

Gao

et al. 2020

Geological Journal

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The eastern Tseel Terrane of SW Mongolia, which is an important part of the Central Asian Orogenic Belt (CAOB), contains a segment of imbricated sheets of Late Palaeozoic granites as well as a bimodal volcanic suite. Late Devonian (380-382 Ma) granites that are enriched in Th, U, and K and depleted in Nb, Ta, P, Ba, Sr, and Ti indicate arc magmatism and are low-K tholeiitic to medium-K calc-alkaline series. Zircon εHf(t) values are of +8.30 to +14.1, with crustal model ages of 0.83-0.48 Ga. The bimodal volcanic suite is composed of N-MORB basalt and 302 ± 2 Ma rhyolite having A 2 -type granite affinities, εHf(t) values ranging from +9.9 to +11.9, and crustal model ages from 0.69 to 0.59 Ga. The rhyolite mighthave originated from partial melting of juvenile lower crust, rather than fractional crystallization of coeval basaltic magma. Late Carboniferous (299-303 Ma) granites are medium-K to high-K calc-alkaline series, crosscutting carbonaceous siltstone, emplaced into the deformed volcanic rocks and are characterized by enrichment in K, Th, and U accompanied by depletion in Ba, Nb, Ta, Sr, P, and Ti in a primitive mantle-normalized diagram with εHf(t) values ranging from +6.05 to +10.6 and crustal model ages from 0.70 to 0.65 Ga. Thus, LA-ICP-MS zircon ages in combination with geochemical data document a phase of arc-related magmatism in the Tseel Terrane at 380-382 Ma. These rocks were subsequently deformed under low-grade metamorphic conditions and intruded by undeformed granites at c. 299-303 Ma. The coeval 302 Ma rhyolite in bimodal volcanic suite shows typical A 2 -type granitic geochemical affinities and probably documents a back-arc basin extensional environment, which was probably related to the roll-back of the Palaeo-Asian Oceanic Plate during the northward subduction under the Central Mongolia microcontinent.

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Nd-Hf Isotopic Decoupling of the Silurian—Devonian Granitoids in the Chinese Altai: A Consequence of Crustal Recycling of the Ordovician Accretionary Wedge?

et al. 2019

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Polycyclic Palaeozoic evolution of accretionary orogenic wedge in the southern Chinese Altai: Evidence from structural relationships and U–Pb geochronology

Cited by 49 publications

References 80 publications

Revision of the Chinese Altai‐East Junggar Terrane Accretion Model Based on Geophysical and Geological Constraints

Revision of the Chinese Altai‐East Junggar Terrane Accretion Model Based on Geophysical and Geological Constraints

Late Palaeozoic magmatism in the eastern Tseel Terrane of SW Mongolia evidenced by chronological and geochemical data

Nd-Hf Isotopic Decoupling of the Silurian—Devonian Granitoids in the Chinese Altai: A Consequence of Crustal Recycling of the Ordovician Accretionary Wedge?

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