The magma plumbing system of the Emeishan large igneous province and its role in basaltic magma differentiation in a continental setting

2015 ◽  
Vol 100 (11-12) ◽  
pp. 2509-2517 ◽  
Author(s):  
Yan Tao ◽  
Keith Putirka ◽  
Rui-Zhong Hu ◽  
Chusi Li
Keyword(s):  
Basaltic Magma ◽  
Large Igneous Province ◽  
Plumbing System ◽  
Magma Differentiation ◽  
Magma Plumbing System ◽  
Emeishan Large Igneous Province ◽  
Igneous Province ◽  
Magma Plumbing

Petrogenesis of Silicic Rocks from the Phan Si Pan - Tu Le region of the Emeishan Large Igneous Province, Northwestern Vietnam

2021 ◽  
pp. SP518-2020-253
Author(s):  
Thuy Thanh Pham ◽  
J. Gregory Shellnutt ◽  
Tuan-Anh Tran ◽  
Steven W. Denyszyn ◽  
Yoshiyuki Iizuka
Keyword(s):  
Basaltic Magma ◽  
Red River ◽  
Granitic Rocks ◽  
Large Igneous Province ◽  
Weighted Mean ◽  
Emeishan Large Igneous Province ◽  
Icp Ms ◽  
Igneous Province ◽  
Single Grain ◽  
Host Rocks

AbstractThe Permian silicic rocks in the Phan Si Pan (PSP) uplift area and Tu Le (TL) basin of NW Vietnam (collectively the PSP-TL region) are associated with the Emeishan Large Igneous Province (ELIP). The Permian Muong Hum, Phu Sa Phin, and Nam Xe - Tam Duong granites, and Tu Le rhyolites are alkali ferroan A1-type granitic rocks, which likely formed by fractional crystallization of high-Ti basaltic magma that was contaminated by melts derived from the Neoproterozoic host rocks. Zircon U-Pb LA-ICP-MS geochronology yielded weighted-mean 206Pb/238U ages of 246 ± 3 Ma to 259 ± 3 Ma for granites, and 249 ± 3 Ma and 254 ± 2 Ma for rhyolites. This is contrasted with previously-published high precision U-Pb ages, obtained using CA-ID-TIMS method applied on the same zircon grains, which suggest that the calculated LA-ICP-MS U-Pb ages are variably inaccurate by up to 10 Ma, though at the single-grain level dates generally agree within uncertainty. The similarity of rock texture, whole-rock geochemistry, emplacement ages, and fractionation phases between the PSP-TL region and silicic rocks in the Inner Zone ELIP (i.e., Panzhihua, Binchuan) suggests they were spatially proximal before being sinistrally displaced along the Ailao Shan-Red River shear zone.

scholarly journals The Temporal Variation of Magma Plumbing System of the Kattadake Pyroclastics in the Zao Volcano, Northeastern Japan

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 430
Author(s):  
Mirai Takebe ◽  
Masao Ban ◽  
Motohiro Sato ◽  
Yuki Nishi
Keyword(s):  
Basaltic Magma ◽  
Alkaline Rock ◽  
Plumbing System ◽  
Calc Alkaline ◽  
Magma Plumbing System ◽  
Shallow Magma Chamber ◽  
Northeastern Japan ◽  
Petrologic Study ◽  
Magma Plumbing ◽  
Ne Japan

The geologic and petrologic study of the Kattadake pyroclastics (around 10 ka) from the Zao volcano (NE Japan) revealed the structure of the magma plumbing system and the mixing behavior of the shallow chamber. The Kattadake pyroclastic succession is divided into lower and upper parts by a remarkable discontinuity. All rocks belong to medium-K, calc-alkaline rock series and correspond to ol-cpx-opx basaltic-andesite to andesite with 20–28 vol% phenocrystic modal percentage. All rocks were formed by mixing between andesitic magma and near aphyric basalt. The petrologic features of andesites of lower and upper parts are similar, 59–61 wt% SiO2, having low-An plagioclase and low-Mg pyroxenes, with pre-eruptive conditions corresponding to 960–980 °C, 1.9–3.5 kb, and 1.9–3.4 wt% H2O. However, the basalts were ca. 49.4 wt% SiO2 with Fo~84 olivine in the lower part and 51.8 wt% SiO2 with Fo~81 olivine and high-An plagioclase the in upper one. The percentage of basaltic magma in the mixing process was lower, but the temperature of the basalt was higher in the lower part than the upper one. This means that the shallow magma chamber was reactivated more efficiently by the hotter basalts and that the mixed magma with a 70–80% of melt fraction was formed by a smaller percentage of the basaltic magma.

scholarly journals Magma Plumbing System of Emeishan Large Igneous Province at the End-Permian: Insights from Clinopyroxene Compositional Zoning and Thermobarometry

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 979
Author(s):  
Jun-Hao Hu ◽  
Jing-Wen Liu ◽  
Tao Song ◽  
Bai-Shun Shi
Keyword(s):  
Tectonic Setting ◽  
Large Igneous Province ◽  
Magma Ascent ◽  
Magma Chambers ◽  
Flood Basalts ◽  
Compositional Zoning ◽  
Magma Plumbing System ◽  
Emeishan Large Igneous Province ◽  
Mafic Intrusions ◽  
Igneous Province

The end-Permian Emeishan Large Igneous Province (ELIP) in SW China is widely accepted to have formed by mantle plume activities, forming voluminous flood basalts and rare picrites. Although many studies were performed on the petrogenesis and tectonic setting, the detailed conditions and processes within the magma chamber(s) remain unsolved. In this study, we studied the sector-/oscillatory-zoned clinopyroxene (Cpx) phenocrysts and performed Cpx-liquid thermobarometric calculation to constrain the physicochemical processes within the magma chambers. The results show that Cpx phenocrysts from the high-Mg basalts were crystallized at 4–27 (average 17) km, whilst those from the low-Mg basalt were crystallized at 0–23 (average 9) km depth. The sector and oscillatory Cpx zoning in the high-Mg basalts show that the magma had experienced undercooling and multistage recharge events in the deep-staging chamber(s). The magma replenishments may have eventually led to the eruption of high-Mg basalts, and magma ascent to the upper crust for further fractionation to form the low-Mg basalts and mafic intrusions.

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