Paleoproterozoic ultrahigh-temperature granulite-facies metamorphism in the Sulu orogen, eastern China: Evidence from zircon and monazite in the pelitic granulite

Xu, Haijin; Lei, Hengcong; Xiong, Zhiwu; Zhang, Junfeng

doi:10.1016/j.precamres.2019.105430

Cited by 21 publications

(2 citation statements)

References 122 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Sulu UHP terrane is bounded by several faults, such as the Wulian–Qingdao and the Mishan faults in the north, the Jiashan – Xiangshui Fault in the south, and the Tanlu Fault in the west (Figure 1b). The Sulu UHP terrane is mainly composed of granitic migmatites (e.g., Chen et al, 2013a, 2013b; Song et al, 2014a, 2014b; Xu, Ye, et al, 2013; Ye, Yao, et al, 2000) with subordinate other lithologies, such as eclogite (e.g., Hirajima et al, 1990; Kato, Enami, & Zhai, 1997; Ye, Cong, et al, 2000; Zhang, Shen, Wang, & Dong, 2009), amphibolite (e.g., Liu, Gerdes, Zeng, & Xue, 2008), peridotite (e.g., Yang, Wooden, & Wu, 2003; Zhang, Hirajima, Banno, Cong, & Liou, 1995), jadeite quartzite, marble (e.g., Kato et al, 1997), paragneiss and pelitic granulite (e.g., Xiang et al, 2014; Xu, Lei, Xiong, & Zhang, 2019), which occur as scattered blocks or lenses within the regional granitic migmatites (e.g., review paper of Liu and Liou (2011)). Evidences of UHP metamorphism, for example, coesite and its pseudomorphs as inclusions in rock‐forming and accessory minerals are widely reported in these UHP rocks (Hirajima et al, 1990; Kato et al, 1997; Liu et al, 2008; Ye, Cong, et al, 2000; Zhang et al, 2009).…”

Section: Geological Setting and Petrologymentioning

confidence: 99%

Anatexis of the deeply subducted continental crust during exhumation: A case study of Rongcheng migmatite in the Sulu orogen

Yang

Wang

et al. 2020

Geological Journal

Self Cite

View full text Add to dashboard Cite

Migmatite in the Sulu ultra‐highpressure (UHP) terrane is an ideal sample to provide information on anatexis during the exhumation of the deeply subducted continental crust. The studied migmatite is composed of the leucosome and melanosome with strongly ductile shear deformation. Petrographic observations clearly show an anatexis process, for example, cuspate and triangular K‐feldspars in triple junction and along grain boundaries, felsic veinlets and pockets mainly consisting of K‐feldspar + quartz + plagioclase ± biotite. The zircon grains of the migmatite have a core‐rim structure: the inherited magmatic core and the anatectic overgrowth rim. The inherited cores exhibit oscillatory zonings in the cathodoluminescence (CL) images and display strong heavy rare earth element (HREE) enrichment with clearly positive Ce and negative Eu anomalies. The inherited cores have an upper intercept U‐Pb age of 814 ± 45 Ma with εHf(t) values of −5.6 to ‐10.6 (mean = −8.5 ± 0.8, n = 16). Thus, protolith of the migmatite is a mid‐Neoproterozoic granitic rock. The overgrowth rims exhibit a typical anatexis genesis, that is, a bright homogeneous luminescence in the CL images, very low Th/U ratios (<0.02) with low U (<100 ppm) and Th (<1 ppm) contents, and lower total REE and Y contents with lower (Gd/Lu)N ratios and higher Hf/Y ratios than the inherited cores. They are Late Triassic with ages ranging from 211 to 234 Ma (mean = 223 ± 8 Ma), which, combined with previous studies on the Sulu UHP terrane, suggests that the anatexis occurred during the early exhumation stage. They have higher Ti‐in‐zircon temperatures ranging from 760 to 813°C (mean = 791 ± 16°C) than the pre‐anatexis zircon (244 ± 5 Ma and 739°C), suggesting a ‘hot’ exhumation. They have εHf(t) values of −17.6 to −14.5 (mean = −15.5 ± 0.6) which are lower than the estimated value (~12.0) on the crustal evolution array, suggesting an addition of crustal fluid during the anatexis. The anatexis also dramatically affected the zircon Lu–Hf isotopic system, that is, 176Yb/177Hf and 176Lu/177Hf isotopic ratios are markedly decreased but initial 176Hf/177Hf ratios are increased from the inherited magmatic cores to the anatectic rims. Thus, we propose that the anatexis plays a critical role in the exhumation of the UHP metamorphic rocks. The anatexis could lubricate the subducted slices and further facilitate their buoyant rise from the mantle depth to the crustal level.

show abstract

Section: Geological Setting and Petrologymentioning

confidence: 99%

Anatexis of the deeply subducted continental crust during exhumation: A case study of Rongcheng migmatite in the Sulu orogen

Yang

Wang

et al. 2020

Geological Journal

Self Cite

View full text Add to dashboard Cite

show abstract

“…Growth of zircon and monazite requires system or local saturation in zirconium, phosphates and rare earth elements (REEs), and in HT rocks generally occurs as melt crystallizes (Fraser et al, 1997; Rubatto et al, 2001; Kelsey et al, 2008; Kelsey & Powell, 2010; Yakymchuk & Brown, 2014; T. E. Johnson et al, 2015). In HT terranes where melting does take place, U–Pb geochronology of monazite and zircon can therefore provide meaningful constraints for the timing and rate of tectono‐metamorphic processes (e.g., Asami et al, 2002; Cutts et al, 2011; Korhonen et al, 2013; Sajeev et al, 2010; Santosh et al, 2006; Schmitz & Bowring, 2003; Xu et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

The inhibited response of accessory minerals during high‐temperature reworking

March,

Hand,

Morrissey

et al. 2023

Journal Metamorphic Geology

View full text Add to dashboard Cite

U–Pb zircon and monazite geochronology are considered to be among the most efficient and reliable methods for constraining the timing of high‐temperature (HT) metamorphic events. However, the reliability of these chronometers is coupled to their ability to participate in reactions. A case study examining the responsiveness of zircon and monazite has been conducted using granulite facies metapelitic and metamafic lithologies in the Warumpi Province, central Australia. In some instances, metapelitic granulites from this locality are polymetamorphic, with an early M1 assemblage containing orthopyroxene, cordierite, biotite, quartz, ilmenite and magnetite, and an M2 assemblage represented by garnet, sillimanite, orthopyroxene, cordierite, biotite, sapphirine, ilmenite and magnetite. M2 metamorphism is linked to HT peak conditions of 8–10 kbar and 850–915°C. Detrital and metamorphic zircon and monazite from these rocks dominantly record U–Pb dates of 1670–1610 Ma and have trace element compositions suggesting they grew prior to peak M2 garnet in the rock. Lu–Hf geochronology from M2 garnet gives ages of c. 1150 Ma. Zircon and monazite are therefore suggested to have remained largely inert during HT metamorphism. We attribute the relatively minor response of zircon and monazite during high‐temperature Mesoproterozoic metamorphism to the localized development of refractory bulk compositions at c. 1630 Ma during M1 metamorphism. This created refractory Mg–Al‐rich bulk compositions that were unable to undergo significant partial melting, despite experiencing subsequent temperatures of ~900°C at c. 1150 Ma. In contrast, metapelitic and metamafic rocks in the area that did not develop refractory bulk compositions during M1 metamorphism were able to partially melt and record c. 1150 Ma accessory mineral U–Pb ages. These results contribute to a small, but growing number of case studies investigating the systematics of the U–Pb system in zircon and monazite in polymetamorphic HT terranes and their apparent resistance to isotopic resetting. Where disequilibrium is apparent, garnet Lu–Hf geochronology can form an important tool to interrogate the significance of accessory U–Pb ages. In the Warumpi Province in central Australia, c. 1640 Ma zircon U–Pb ages had previously been interpreted to reflect the formation of HT garnet‐bearing granulites during a collisional event. Instead, the garnet‐bearing assemblages formed at c. 1150 Ma during the Mesoproterozoic, calling into question the existence of a late Palaeoproterozoic collisional system in central Australia.

show abstract

Genesis of baddeleyite and high δ18O zircon in impure marble from the Tongbai orogen, Central China: insights from petrochronology and Hf–O isotope compositions

Zhou

et al. 2020

Contrib Mineral Petrol

View full text Add to dashboard Cite

Paleoproterozoic ultrahigh-temperature granulite-facies metamorphism in the Sulu orogen, eastern China: Evidence from zircon and monazite in the pelitic granulite

Cited by 21 publications

References 122 publications

Anatexis of the deeply subducted continental crust during exhumation: A case study of Rongcheng migmatite in the Sulu orogen

Anatexis of the deeply subducted continental crust during exhumation: A case study of Rongcheng migmatite in the Sulu orogen

The inhibited response of accessory minerals during high‐temperature reworking

Genesis of baddeleyite and high δ18O zircon in impure marble from the Tongbai orogen, Central China: insights from petrochronology and Hf–O isotope compositions

Contact Info

Product

Resources

About