Metamorphic P-T path and SIMS zircon U-Pb dating of amphibolite of the Namche Barwa Complex, southeast Tibet, China

Peng, Tao; Zeng, Lingsen; Gao, Li-E; Gerdes, Axel; Gao, Jianjun; Hu, Zeng; Wu, Chun‐Ming

doi:10.1016/j.lithos.2018.10.002

Cited by 12 publications

(19 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…500 Ma) and the amphibolites were derived from mafic magmatic rocks of Late Paleoproterozoic age (1650–1600 Ma; Zhang et al, 2010, 2012). All the rocks of the HHC underwent high‐grade metamorphism and partial melting during the Cenozoic, with the metamorphic and magmatic zircon U‐Pb ages ranging from 40 to 7 Ma (Booth et al, 2004, 2009; Burg et al, 1998; Ding et al, 2001; Liu et al, 2007; Peng et al, 2018; Su et al, 2012; Tian et al, 2016; Xu et al, 2010; Zhang et al, 2010, 2012, 2015).…”

Section: Geological Setting and Sample Descriptionmentioning

confidence: 99%

“…55-50 Ma (Ding et al, 2016;Guillot et al, 2003;Meng et al, 2012;Najman et al, 2010;Yin & Harrison, 2000;Zhang et al, 2019;Zhu et al, 2015), and is typical of large hot orogens (Beaumont et al, 2006(Beaumont et al, , 2010. Available studies have shown that ultrahigh pressure (UHP) and high-pressure (HP) metamorphic rocks occur in the western Himalaya (Ahmad et al, 2006;Guillot et al, 2008;Kaneko et al, 2003;Kouketsu et al, 2015;Lanari et al, 2013;O'Brien, 2019;O'Brien et al, 2001) and HP granulites and retrogressed eclogites occur throughout the central Himalaya (Chakungal et al, 2010;Cottle，Jessup, et al, 2009;Groppo et al, 2007;Kohn, 2014;Li et al, 2018;Lombardo et al, 2016;Lombardo & Rolfo, 2000;Wang et al, 2017), whereas only HP granulites are exposed in the eastern Himalayan syntaxis (EHS) (Booth et al, 2009;Ding et al, 2001;Guilmette et al, 2011;Liu & Zhong, 1997;Peng et al, 2018;Su et al, 2012;Tian et al, 2016;Xu et al, 2010;Zhang et al, 2010;Zhu et al, 2015). The Higher Himalayan Crystallines (HHC) and leucogranites in the metamorphic core of the Himalayan orogen provide an excellent natural laboratory for studying the tectonic evolution of large hot orogens.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Prolonged Partial Melting of Garnet Amphibolite from the Eastern Himalayan Syntaxis: Implications for the Tectonic Evolution of Large Hot Orogens

et al. 2020

View full text Add to dashboard Cite

The Himalayan orogen, which formed due to collision of the Indian and Asian continents during the Early Tertiary, is a prime example of a large, hot collisional orogen. Despite decades of study, the duration of partial melting of migmatitic rocks exposed in the Himalayan orogenic core remains highly controversial. As such, we have performed detailed petrological and geochronological analyses of garnet amphibolite from the eastern Himalayan syntaxis in order to reveal the thermal conditions, tectonometamorphic mechanisms, and timing and duration of anatexis in metabasic rocks that form a major component of the thickened lower crust of the eastern Himalayan orogen. Phase equilibrium modeling and geothermobarometry show that the studied sample underwent high-pressure granulite-facies metamorphism and partial melting at 15−17 kbar and 805−840°C. Dehydration melting of amphibole during prograde metamorphism generated up to 20 vol. % partial melt with a granitic composition, which thus represents a potential source for Himalayan syn-to post-orogenic crustal-derived granites. Zircon U-Pb geochronology shows that the garnet amphibolite witnessed a long-lived anatectic and melt crystallization process lasting more than 30 Myr. Prolonged anatexis from ca. 40 to ca. 20 Ma predates initiation of the extrusion of Himalayan metamorphic core by up to 15 Myr, indicating that the thick and weak crust of the Himalayan-Tibetan orogen must have remained stationary for this length of time, despite the ongoing continental collision. This study thus provides new insight into the tectonic evolution of hot orogens. Plain Language Summary We have conducted petrological and geochronological studies of garnet amphibolite from the eastern segment of Himalayan-Tibetan orogen. Our results show that the rock experienced a prolonged high-pressure and high-temperature metamorphic and partial melting process from ca. 40 to ca. 20 Ma, indicating that the thickened, molten lower crust of the large hot orogen remained stationary for 15 Myr and then extruded toward the surface during ongoing continental collisional orogeny.

show abstract

Section: Geological Setting and Sample Descriptionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Prolonged Partial Melting of Garnet Amphibolite from the Eastern Himalayan Syntaxis: Implications for the Tectonic Evolution of Large Hot Orogens

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Otherwise, monazite shows a general trend to a stronger negative Eu anomaly (decrease in Eu N /Eu N * value, Figure 8) at younger ages, which could result from the K‐feldspar growth when melting occurred in metapelitic rocks (Rubatto et al, 2013). Therefore, the youngest age yielded by monazite may indicate that the decompressional melting in the NBC ensued to as young as ~ 3 Ma, which is consistent with the protracted high‐ T metamorphism in the NBC (e.g., Koons et al, 2013; Peng et al, 2018; Zeitler et al, 2001; Zhang et al, 2018).…”

Section: Discussionmentioning

confidence: 65%

“…Sample NB31 (29°32′35.58″N, 94°53′29.71″E ) is from the transitional zone of the Zhibai and Paixiang formations, between the Namu–La and Namche Barwa thrusts (Figure 1 and 2a), whereas the other three samples NB12, NB13 (29°28′37.53″N, 94°44′10.68″E) and X15 (29°28′15″N, 94°43′41″E) collected from the Paixiang formation, on the footwall of the Namu–La thrust (Figure 1 and 2b,c). The two amphibolite samples from within (X20) and outside (NB06) of the ‘pop‐up’ structure were previously investigated by Peng et al (2018), and in this study, we obtained additional in situ titanite U–Pb ages.…”

Section: Geological Settingsmentioning

confidence: 94%

“…Reported metamorphic peak P–T conditions range from 11 to 18 kbar and 750°C to 950°C (Booth et al, 2009; Ding et al, 2001; Guilmette et al, 2011; Liu & Zhang, 2014; Liu & Zhong, 1997; Palin Ding & Zhong, 1999; Tian et al, 2016, 2017; Zhang et al, 2015). The different constraints on metamorphic ages (from ~40 to 1 Ma, Booth et al, 2009; Ding et al, 2001; Peng et al, 2018; Su et al, 2012; Tian et al, 2017; Xu et al, 2012; Zeitler et al, 2014; Zeng et al, 2012; Zhang et al, 2010, 2012, 2018), and limited in situ dating of accessory minerals of the NBC (Booth et al, 2009; Liu et al, 2011) impede our understanding of the tectono‐metamorphic evolution of the NBC and obscure the relationship between the various driving forces that formed this area. In this study, we applied in situ laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) U–Th–Pb dating, trace element analyses of monazite and conventional geothermobarometry to retrieve the metamorphic P–T–t path of metapelite exposed in the NBC and to shed a light on the discrepancy among the reported metamorphic ages.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Divergent metamorphism within the Namche Barwa Complex, the Eastern Himalaya, Southeast Tibet, China: Insights from in situ U–Th–Pb dating of metamorphic monazite

Peng

Gerdes

Zeng

et al. 2021

Journal Metamorphic Geology

Self Cite

View full text Add to dashboard Cite

Geothermobarometry shows that metapelite samples from Namche Barwa Complex (NBC) reached upper amphibolite to near‐granulite facies during the peak metamorphic stage, with similar conditions of ~700–750°C/8–10 kbar, and then experienced retrograde metamorphism at ~630–700°C/4–7 kbar. In situ monazite laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) U–Th–Pb dating suggests divergent metamorphism in the NBC: metapelite on the hanging wall of Namu–La thrust preserved a continuous metamorphic record of >19–3 Ma, whereas metapelite on the footwall yielded age ranges of >18–14 and 8–3 Ma, with a gap in recorded ages between 14 and 8 Ma. Monazite grains in the garnet porphyroblasts, more depleted in the heavy rare earth elements (HREE), yielded the youngest age of ~14 Ma. This is interpreted as the timing of upper amphibolite facies peak metamorphism in the metapelite from the NBC, with the NBC being exhumed coherently thereafter. Furthermore, the discrepancy between reported peak metamorphic ages of high‐pressure granulite (~40–30 Ma, ~25–20 Ma) and mid‐pressure metapelite (~14 Ma, this study) indicate asynchronous subduction–exhumation processes in the NBC. We suggest that crustal flow has played an essential role in exhumation since ~40 Ma, and recent surficial erosion (<8 Ma) intensified the exhumation of the NBC, with young leucogranite (<10 Ma) resulting from decompression melting. From ~3 Ma to the present, the interplay of erosion and tectonic movement caused ubiquitous rapid uplift, resulting in the concomitant exhumation of various types of rocks and the formation of the spectacular high relief between Yarlung Tsangpo Gorge and Namche Barwa Peak.

show abstract

Contrasting CW and CCW tectono-metamorphic belts in the eastern Himalayan syntaxis: quantification of P–T–t paths and tectonic interpretation

et al. 2020

View full text Add to dashboard Cite

Metamorphic P-T path and SIMS zircon U-Pb dating of amphibolite of the Namche Barwa Complex, southeast Tibet, China

Cited by 12 publications

References 67 publications

Prolonged Partial Melting of Garnet Amphibolite from the Eastern Himalayan Syntaxis: Implications for the Tectonic Evolution of Large Hot Orogens

Prolonged Partial Melting of Garnet Amphibolite from the Eastern Himalayan Syntaxis: Implications for the Tectonic Evolution of Large Hot Orogens

Divergent metamorphism within the Namche Barwa Complex, the Eastern Himalaya, Southeast Tibet, China: Insights from in situ U–Th–Pb dating of metamorphic monazite

Contrasting CW and CCW tectono-metamorphic belts in the eastern Himalayan syntaxis: quantification of P–T–t paths and tectonic interpretation

Contact Info

Product

Resources

About