Petrogenesis of the Triassic Bayan-Ulan alkaline granitic pluton in the North Gobi rift of central Mongolia: Implications for the evolution of Early Mesozoic granitoid magmatism in the Central Asian Orogenic Belt

Dostál, J.; Owen, J. Victor; Shellnutt, J. Gregory; Keppie, J. Duncan; Gerel, Ochir; Corney, R.

doi:10.1016/j.jseaes.2015.04.021

Cited by 10 publications

(8 citation statements)

References 52 publications

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“…An Andean‐type arc setting could plausibly account for their petrogenesis (e.g., Li et al, ; Tang et al, , ). In the modern Andes, active continental margin low‐angle or flat‐slab subduction occurs, and the following observations also indicate the existence of the low‐angle or flat‐slab subduction during the Triassic for the southwards subduction of the Mongol–Okhotsk oceanic plate: Late Triassic I‐type granite (Arynnur granite; Jiang, Nie, Su, Cai, & Ding, ; Liu et al, ), A‐type granites, and bimodal volcanics (Baga–Gazriin granites; Olzit granites, basalts, and rhyolites; Kharkhorin basalts and rhyolites; Yarmolyuk et al, ; Machowiak & Stawikowski, ; Machowiak et al, ; Ochir & Dostal, ; Dostal et al, ; Zhu et al, ) crop out in the Central Mongolia Massif (Figures a, , , and a), which is located approximately >200 km (Olzit, Tumurtin Ovoo, Arynnur, Badaguan, Shanghulin‐Mordaoga; Figure ) south‐east of the Mongol–Okhotsk Suture Zone. Such a long distance requires long‐lasting low‐angle or flat‐slab subduction.…”

Section: Discussionmentioning

confidence: 81%

Southward subduction of the Mongolia–Okhostk Ocean: Insights from Early–Middle Triassic intrusive rocks from the Jiawula–Tsagenbulagen area in NE China

et al. 2019

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New zircon U-Pb age data, Hf isotopes, whole-rock major and trace elements, and Sr-Nd isotopic data for Early-Middle Triassic intrusive rocks from the Jiawula and Tsagenbulagen area in the southern part of the Erguna Massif provide valuable constraints on the southward subduction of the Mongolia-Okhostk Ocean lithosphere. The Jiawula-Tsagenbulagen granitoids mainly consist of granodiorite, quartz monzonite, and biotite granite. These granitoids, long believed to be mainly Late Jurassic-Early Cretaceous (ca. 150-139 Ma) and minor Permian (ca. 278 Ma and 254-253 Ma), are newly found to contain a latest Early Triassic to Middle Triassic generation (zircon U-Pb age: ca. 248-244 Ma). Geochemically, the Early to Middle Triassic granitoids are characterized by high SiO 2 (74-77 wt.%) and Al 2 O 3 (12.2-15.95 wt.%), low Mg # values (12.98-37.32), and variable Na 2 O/K 2 O ratios (0.62-1.75). They are metaluminous to peraluminous and belong to the high-K calcalkaline series. Moreover, they show enrichment in light rare earth elements and large-ion lithophile elements and depletion in heavy rare earth elements and highfield-strength elements (e.g., Nb, Ta, and Ti). They have an increased amount of SiO 2 /Al 2 O 3 but lower V/Th ratios and negative correlations between V/Th and SiO 2 / Al 2 O 3 ratios, indicating that the magmas experienced various degrees of biotite and/or plagioclase fractional crystallization. Their whole-rock ε Nd (t) and zircon ε Hf (t)values ranged from +1.07 to +4.15 and from +0.5 to +2.9, respectively, indicating that the primary magmas were probably generated by partial melting of juvenile crustal material with the help of mantle-derived mafic magmas. These magmas subsequently underwent fractional crystallization, magma mixing, and a small amount of crustal contamination during their emplacement. The geochemical characteristics of these Early-MiddleTriassic intrusive rocks have affinities with intrusive rocks from active continental margin settings. Therefore, we conclude that the Early-Middle Triassic magmatism in the Erguna Massif was generated within an Andean-type arc setting related to the southwards subduction of the Mongol-Okhotsk oceanic plate beneath the Erguna Massif. We summarized previous age data of the Early to Late Triassic magmatic rocks from Erguna and Central Mongolia and identified arc setting granites and post-orogenic granites. Thus, a tectonic evolutionary model was proposed for the geological observations in the Erguna and Central Mongolia massifs, involving the Triassic continuous

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Section: Discussionmentioning

confidence: 81%

Southward subduction of the Mongolia–Okhostk Ocean: Insights from Early–Middle Triassic intrusive rocks from the Jiawula–Tsagenbulagen area in NE China

et al. 2019

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“…In addition to the TP rocks, 12 samples from the Bayan-Ulan granitic intrusion (see section "Relationship between petrogenesis and mineralization") were also analyzed ( Supplementary Table S2). These samples do not appear to be noticeably affected by secondary processes (Dostal et al, 2015b).…”

Section: Sampling and Alterationmentioning

confidence: 83%

“…The intrusions of the megadome show a concentrically zoned arrangement (Figure 2) where the Khentei batholith is in the center of the bulge and is surrounded by three rift zones: Western Transbaikalian, Kharkhorin (Karakorum), and North Gobi. The rift zones consist of horsts, grabens, and depressions containing Upper Permian to Upper Triassic clastic sedimentary rocks and bimodal volcanic suites (Yarmolyuk et al, 2002) and Mesozoic granitic plutons (e.g., Dostal et al, 2014Dostal et al, , 2015bAntipin et al, 2016). The age of the plutons of the rift zones range typically between 221 and 186 Ma (Yarmolyuk et al, 2002;Dostal et al, 2014).…”

Section: Geological Settingmentioning

confidence: 99%

“…To evaluate the differences between the granitic rocks of the TP, a representative intrusion of the Khentei batholith, and those of the rift zones, the TP rocks are compared with those of the Bayan-Ulan pluton (221 Ma; Dostal et al, 2015b) from the North Gobi rift zone (Figure 2). For comparison, which might also reveal a contrast between the ore-bearing and barren granites, we have augmented the Bayan-Ulan whole-rock analyses of Dostal et al (2015b) with the new data (Supplementary Table S2). The Bayan-Ulan pluton (BU), located about 200 km east of Ulaanbaatar, outcrops over an area of ∼1000 km 2 .…”

Section: Comparison With Granites Of the Rift Zonesmentioning

confidence: 99%

“…The Bayan-Ulan pluton (BU), located about 200 km east of Ulaanbaatar, outcrops over an area of ∼1000 km 2 . The intrusion (Dostal et al, 2015b) is composed mainly of coarse-grained leucocratic granite containing mesoperthite with interstitial quartz and minor to trace amounts of Fe-rich alkali amphiboles and, rarely, Fe-rich biotite. The granites have relatively uniform chemical compositions; they are highly fractionated alkaline A2-type granites with silica ranging from 75 to 78.5 wt.% (Figure 7).…”

Section: Comparison With Granites Of the Rift Zonesmentioning

confidence: 99%

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Early Jurassic Rare Metal Granitic Pluton of the Central Asian Orogenic Belt in North-Central Mongolia: Tungsten Mineralization, Geochronology, Petrogenesis and Tectonic Implications

et al. 2020

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The Tukhum granitic pluton is a part of the Mesozoic composite Khentei batholith of north-central Mongolia, which belongs to the Central Asian Orogenic Belt. The shallowseated pluton (∼900 km 2) is made up of two distinct biotite granite intrusions dated at ∼191 and 183 Ma and hosts a tungsten deposit associated with the younger phase. Both intrusions are composed of ferroan A2-type granites, which are fractionated and silica-rich (>71 wt.%). Their mantle-normalized plots are relatively enriched in Cs, Rb, U, and Th and depleted in Ba, Sr, Eu, Nb, and Ti. They have ε Nd (t) ranging from ∼0 to +1 and Nd model ages ∼650-900 Ma. The granites were derived by partial melting of a Neoproterozoic middle/lower crustal source of felsic/intermediate composition, followed by fractional crystallization. The younger intrusion also contains leucogranites with a trace element composition indicative of a combined crystal and fluid fractionation. The source of this younger intrusion was enriched in rare metals (W, Sn). The tungsten deposit is associated with the last stages of the evolution of the granitic magma. The origin of the pluton as well as the Khentei batholith is related to a mantle plume, which provided the heat triggering a crustal melting. The plume resulted in the eastward movement of large-scale magmatism over time, from the Tarim traps (300-275 Ma) through the large Khangai magmatic center (270-240 Ma) to the Khentei batholith (230-180 Ma) in north-central Mongolia.

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Late Neoproterozoic to Carboniferous genesis of A-type magmas in Avalonia of northern Nova Scotia: repeated partial melting of anhydrous lower crust in contrasting tectonic environments

Murphy

Shellnutt

Collins

2017

Int J Earth Sci (Geol Rundsch)

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Petrogenesis of the Triassic Bayan-Ulan alkaline granitic pluton in the North Gobi rift of central Mongolia: Implications for the evolution of Early Mesozoic granitoid magmatism in the Central Asian Orogenic Belt

Cited by 10 publications

References 52 publications

Southward subduction of the Mongolia–Okhostk Ocean: Insights from Early–Middle Triassic intrusive rocks from the Jiawula–Tsagenbulagen area in NE China

Southward subduction of the Mongolia–Okhostk Ocean: Insights from Early–Middle Triassic intrusive rocks from the Jiawula–Tsagenbulagen area in NE China

Early Jurassic Rare Metal Granitic Pluton of the Central Asian Orogenic Belt in North-Central Mongolia: Tungsten Mineralization, Geochronology, Petrogenesis and Tectonic Implications

Late Neoproterozoic to Carboniferous genesis of A-type magmas in Avalonia of northern Nova Scotia: repeated partial melting of anhydrous lower crust in contrasting tectonic environments

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