U–Th dating of zircons from Holocene potassic andesites (Maanshan volcano, Tengchong, SE Tibetan Plateau) by depth profiling: Time scales and nature of magma storage

Zou, Haibo; Fan, Qicheng; Schmitt, Axel K.; Sui, Jianli

doi:10.1016/j.lithos.2010.05.001

Cited by 63 publications

(20 citation statements)

References 49 publications

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“…Earlier isotopic studies suggested that the Tengchong lavas underwent very little contamination (Zhu et al 1983;Chen et al 2002;Zou et al 2010), despite the presence of abundant crustal xenocrysts (Fig. 3e, f).…”

Section: Crustal Contaminationmentioning

confidence: 90%

Heterogeneous mantle source and magma differentiation of quaternary arc-like volcanic rocks from Tengchong, SE margin of the Tibetan Plateau

Zhou

Robinson

Wang

et al. 2011

Contrib Mineral Petrol

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The Tengchong volcanic field north of the Burma arc comprises numerous Quaternary volcanoes in the southeastern margin of the Tibetan Plateau. The volcanic rocks are grouped into four units (1-4) from the oldest to youngest. Units 1, 3 and 4 are composed of olivine trachybasalt, basaltic trachyandesite and trachyandesite, and Unit 2 consists of hornblende dacite. The rocks of Units 1, 3, and 4 form a generally alkaline suite in which the rocks plot along generally linear trends on Harker diagrams with only slight offset from unit to unit. They contain olivine phenocrysts with Fo values ranging from 65 to 85 mol% and have Cr-spinel with Cr# ranging from 23 to 35. All the rocks have chondrite-normalized REE patterns enriched in LREE and primitive mantlenormalized trace element patterns depleted in Ti, Nb and Ta, but they are rich in Th, Ti and P relative to typical arc volcanics. Despite minor crustal contamination, 87 Sr/ 86 Sr ratios (0.706-0.709), eNd values (-3.2 to -8.7), and eHf values (?4.8 to -6.4) indicate a highly heterogeneous mantle source. The Pb isotopic ratios of the lavas ( 206 Pb/ 204 Pb = 18.02-18.30) clearly show an EMI-type mantle source. The underlying mantle source was previously modified by subduction of the Neo-Tethyan oceanic and Indian continental lithosphere. The present heterogeneous mantle source is interpreted to have formed by variable additions of fluids and sediments derived from the subducted Indian Oceanic lithosphere, probably the Ninety East Ridge. Magma generation and emplacement was facilitated by transtensional NS-trending strike-slip faulting.

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Section: Crustal Contaminationmentioning

confidence: 90%

Heterogeneous mantle source and magma differentiation of quaternary arc-like volcanic rocks from Tengchong, SE margin of the Tibetan Plateau

Zhou

Robinson

Wang

et al. 2011

Contrib Mineral Petrol

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“…Given the extremely low velocity of Layer A with little thickness variations across both profiles, the layer is most likely to represent heavily weathered crustal materials near the surface. Surface mapping shows that the study area is an igneous region with basalts, andesitic decites and basaltic andesites (e.g., Zou et al 2010), and borehole data confirm the igneous nature of the shallow crust (e.g., Tan et al 2013). The reduced velocity of Layer B therefore indicates that the layer contains relatively high levels of fracturing because lithological difference alone cannot account for the observed low seismic velocity.…”

Section: Near-surface Seismic Images Between Intra-plate Volcanic Clumentioning

confidence: 68%

“…The entire length of the IAVZ in the Tengchong area is around 50 km. Using results from geochronological studies (Zou et al 2010;Yu et al 2012), we observe that the ages of the volcanic rocks found in the vicinity of the volcanoes in Tengchong overlap considerably (\0.1-0.8 Ma) and do not show systematic spatial variations.…”

Section: Overview Of Tengchong As An Intra-plate Axial Volcanic Zone mentioning

confidence: 87%

“…1a) with significant volcanic activities in the Holocene (Wang et al 2006;Zou et al 2010). Although the most recent volcanic eruption took place in 1609, the area remains volcanically and hydrothermally active (Zhu et al 1983;Yin 2000;Wang et al 2001;Lei et al 2009).…”

Section: Overview Of Tengchong As An Intra-plate Axial Volcanic Zone mentioning

confidence: 99%

“…By considering the spatial distribution of all 25 volcanic craters in the study area (Fig. 1c) from the published literature (Jia 2005;Zou et al 2010), we are able to identify an elongated volcanic region with a consistently NNE-trending axis (Fig. 1c).…”

Section: Overview Of Tengchong As An Intra-plate Axial Volcanic Zone mentioning

confidence: 99%

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Crustal Structure of the Tengchong Intra-plate Volcanic Area

Qian

Tong

2015

Surv Geophys

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We here provide an overview of our current understanding of the crustal structure of Tengchong in southwest China, a key intra-plate volcanic area along the Himalayan geothermal belt. Given that there is hitherto a lack of information about the near-surface structure of intra-plate volcanic areas, we present the first seismic reflection and velocity constraints on the shallow crust between intra-plate volcanoes. Our nearsurface seismic images reveal the existence of dome-shaped seismic reflectors (DSRs) in the shallow crust between intra-plate volcanic clusters in Tengchong. The two DSRs are both *2 km wide, and the shallowest parts of the DSRs are found at the depth of 200-300 m. The velocity model shows that the shallow low-velocity layer (\4 km/s) is anomalously thick (*1 km) in the region where the DSRs are observed. The presence of DSRs indicates significant levels of intra-plate magmatism beneath the along-axis gap separating two volcano clusters. Along-axis gaps between volcano clusters are therefore not necessarily an indicator of lower levels of magmatism. The seismic images obtained in this technically challenging area for controlled-source seismology allow us to conclude that shallow crustal structures are crucial for understanding the along-axis variations of magmatism and hydrothermal activities in intra-plate volcanic areas.

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Zircon growth in (U)HP quartzo-feldspathic host gneisses exhumed in the Woodlark Rift of Papua New Guinea

Zirakparvar

Baldwin

Schmitt

2014

Geochem. Geophys. Geosyst.

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U–Th dating of zircons from Holocene potassic andesites (Maanshan volcano, Tengchong, SE Tibetan Plateau) by depth profiling: Time scales and nature of magma storage

Cited by 63 publications

References 49 publications

Heterogeneous mantle source and magma differentiation of quaternary arc-like volcanic rocks from Tengchong, SE margin of the Tibetan Plateau

Heterogeneous mantle source and magma differentiation of quaternary arc-like volcanic rocks from Tengchong, SE margin of the Tibetan Plateau

Crustal Structure of the Tengchong Intra-plate Volcanic Area

Zircon growth in (U)HP quartzo-feldspathic host gneisses exhumed in the Woodlark Rift of Papua New Guinea

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