Stability of zircon in dunite at 1400–1550°C

Anfilogov, V. N.; Краснобаев, А. А.; Ryzhkov, V. M.; Kabanova, Larisa Ya.; Valizer, P. M.; Blinov, Ivan A.

doi:10.1134/s1028334x15090159

Cited by 14 publications

(5 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, zircon is being increasingly reported within mantlederived xenoliths (Liati and Gebauer, 2002;Liati et al, 2004;Zheng et al, 2006aZheng et al, , 2006bLi et al, 2016), mafic granulites (Zhang et al, 2018), and peridotites (Grieco et al, 2001;Katayama et al, 2003;Zhang et al, 2011;Zheng et al, 2014), or even within rodingites and their blackwalls (Dubinska et al, 2004;Li et al, 2010;Fukuyama et al, 2014;Zhang et al, 2014). With the exception of rodingites, zircon coexists in all other types of rocks with mineral assemblages equilibrated at high mantle temperatures, which is consistent with experimental results that point to the stability of zircon in dunite at 1400-1550 °C (Anfilogov et al, 2015). In these cases, the formation of the zircon is linked to melt-peridotite metasomatism due to the migration of fluids/melts during the upwelling of the asthenosphere or downgoing of the lithosphere.…”

Section: Zircon Originsupporting

confidence: 79%

Geochemistry and origin of zircon in chlorite schists of the Ronda peridotites (Betic Cordilleras, southern Spain)

2019

View full text Add to dashboard Cite

This work deals with scarce chlorite schists scattered through the Ronda peridotites (Betic Cordilleras, Spain). These schists have unusually high zircon contents, which contrast with the usual lack of this mineral in ultramafic rocks. From field data and detailed petrographic, geochemical, and geothermometric studies, we focused on the origin of the zircon, a relevant issue for the interpretation of geochronological results. The chlorite schists appear as concordant sheets with granite dikes and as blackwall zones between dikes and serpentinized peridotites. As the intrusion age of the dikes and chlorite schist zircon crystallization (ca. 22 Ma) is slightly older than the age of serpentinization and related chlorite schist formation (ca. 19 Ma), we propose that the chlorite schists are tied to the intrusion of the granite dikes and the subsequent serpentinization of peridotites. Trace and rare earth elements alone are not indicative of the magmatic or hydrothermal origin of the zircon, but the combination of information about zircon morphology, melt inclusions, geothermometry, and the structural relationships between granite dikes and chlorite schists points to late magmatic melts for the zircon origin. We suggest that high-temperature melts saturated in F and Cl acted as Zr carriers under low-pH conditions. A change of the pH conditions, due to hydrothermal alkaline fluids incoming for the concomitant peridotite serpentinization, would have led to zircon crystallization and concentration at the apical zones of the dikes, and to rodingitization before the extensive observed chloritization.

show abstract

Section: Zircon Originsupporting

confidence: 79%

Geochemistry and origin of zircon in chlorite schists of the Ronda peridotites (Betic Cordilleras, southern Spain)

2019

View full text Add to dashboard Cite

show abstract

“…Unfortunately, the experimental temperature is limited by the thermal decomposition of zircon, which may hinder, or even prevent, work with natural specimens. At atmospheric pressure pure ZrSiO 4 decomposes to SiO 2 + ZrO 2 at 1673 ± 10 °C 30 , but the transformation occurs at much lower temperature, around 1400 °C, if: zircon contains impurities 31 ; or reacts with a silica-subsaturated phase such as forsteritic olivine to form baddeleyite + orthopyroxene 32 . Váczi et al .…”

Section: Methodsmentioning

confidence: 99%

Experimental evidence for the preservation of U-Pb isotope ratios in mantle-recycled crustal zircon grains

Беа

Montero

Molina

2018

Sci Rep

View full text Add to dashboard Cite

Zircon of crustal origin found in mantle-derived rocks is of great interest because of the information it may provide about crust recycling and mantle dynamics. Consideration of this requires understanding of how mantle temperatures, notably higher than zircon crystallization temperatures, affected the recycled zircon grains, particularly their isotopic clocks. Since Pb2+ diffuses faster than U4+ and Th+4, it is generally believed that recycled zircon grains lose all radiogenic Pb after a few million years, thus limiting the time range over which they can be detected. Nonetheless, this might not be the case for zircon included in mantle minerals with low Pb2+ diffusivity and partitioning such as olivine and orthopyroxene because these may act as zircon sealants. Annealing experiments with natural zircon embedded in cristobalite (an effective zircon sealant) show that zircon grains do not lose Pb to their surroundings, although they may lose some Pb to molten inclusions. Diffusion tends to homogenize the Pb concentration in each grain changing the U-Pb and Th-Pb isotope ratios proportionally to the initial 206Pb, 207Pb and 208Pb concentration gradients (no gradient-no change) but in most cases the original age is still recognizable. It seems, therefore, that recycled crustal zircon grains can be detected, and even accurately dated, no matter how long they have dwelled in the mantle.

show abstract

“…The preservation of zircons that spent such a long time within the extreme P -T conditions of the mantle also needs an explanation. Recent (Anfilogov et al, 2015) experimental studies elucidate the interaction between zircon crystals and dunite at 1400-1550 • C. It was shown that at 1400 • C, no interaction of zircon with dunite takes place, and only at higher temperatures does an interaction between zircon and olivine occur, forming an eutectoid mixture of baddeleyite and pyroxene grains. Therefore zircon is very resistant to metamorphic changes, and it explains the coexistence of zircons of different ages, formed under repeating high-temperature processes.…”

Section: Geology Of Ophiolitesmentioning

confidence: 99%

New data on geology of the Southern Urals: a concise summary of research after the period of EUROPROBE activity

Puchkov¹

2016

Preprint

View full text Add to dashboard Cite

Abstract. The period of an official activity of the EUROPROBE commission was inconnected in the Urals with implementation of the URALIDES Program, that stimulated many qualified geologists from the Western research institutes and Universities to come to the region and work with local geologists at actual problems of the Uralian geology. The author tries to answer a question: what interesting results had been obtained in the Southern Urals in the last decade, when the most of foreign researchers left the Urals, and how these results correspond to the scientific conclusions that had been done before.

show abstract

Stability of zircon in dunite at 1400–1550°C

Cited by 14 publications

References 7 publications

Geochemistry and origin of zircon in chlorite schists of the Ronda peridotites (Betic Cordilleras, southern Spain)

Geochemistry and origin of zircon in chlorite schists of the Ronda peridotites (Betic Cordilleras, southern Spain)

Experimental evidence for the preservation of U-Pb isotope ratios in mantle-recycled crustal zircon grains

New data on geology of the Southern Urals: a concise summary of research after the period of EUROPROBE activity

Contact Info

Product

Resources

About