Skip to main content
Log in

Formation and prolonged preservation of dense arc root cumulates: insights from retrograded eclogite xenoliths in the western Yangtze craton

  • Original Paper
  • Published:
Contributions to Mineralogy and Petrology Aims and scope Submit manuscript

Abstract

Delamination of dense mafic/ultramafic materials in arc roots has long been considered as the fundamental step in the paradigm of making an andesitic continental crust. However, the complexity in identifying ancient arc roots inherently with repeated modifications, poses a challenge in accurately determining the preservation time of the dense crustal materials and thus the delamination-driven model. Here, we conducted comprehensive petrographic, whole-rock, and mineral geochemical studies on 10 variably retrograded eclogite xenoliths from the ~ 35 Ma crustal-derived felsic porphyry in the Liuhe area, western Yangtze craton. Eclogite facies metamorphism is indicated by the fresh relic consisting of coarse-grained garnet, omphacite and rutile; the retrograde metamorphism is manifested by an additional assemblage of fine-grained diopside, amphibole, plagioclase, and biotite. Whole-rock element contents of the xenoliths generally display correlations with immobile Nb concentrations, suggestive of a dominant control from magmatic processes with negligible effects from the post-magmatic alteration. The protoliths of studied xenoliths are most likely accumulated garnet pyroxenites, where the negative correlation between heavy rare earth elements and Mg# (Mg/(Mg + Fe), atomic ratio), and the absence of positive Eu and Sr anomalies suggest the accumulation of garnet under high-pressure conditions. The parental magmas are inferred to be evolved and hydrous with arc-type trace-element patterns. Combined with studies on regional xenoliths, outcrops and tectonic history, the parental magmas likely record the melting of asthenospheric mantle wedge fluxed by recycled subducted slab in the Neoproterozoic (~ 800 Ma). The prolonged preservation (from ~ 800 Ma to at least 35 Ma) of the accumulated garnet pyroxenites with high densities in the deep continental crust can be ascribed to the support from the underlying refractory lithospheric mantle strengthened by plume head accretions. Therefore, we propose that the density-driven delamination of the arc root materials is more sluggish than previously expected and the longevity of dense crustal materials highlights the caution in understanding the role of arc root delamination in making an andesitic continental crust.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10

Similar content being viewed by others

Data availability

The authors confirm that the data supporting the findings of this study are available within the supplementary materials.

References

Download references

Acknowledgements

We would like to thank the editor Prof. Dante Canil and three reviewers (Prof. Emily J. Chin and two anonymous) for their constructive comments that greatly improved the manuscript. We also thank Hao-Qin Sun for assistance in SEM analysis, Fa-Bin Pan for assisting in EPMA analysis, and Di Zhang, Jia-Qi Liang, and Tao Luo for assisting in LA-ICP-MS analysis. This work was jointly supported by the Second Tibetan Plateau Scientific Expedition and Research Program (STEP) (2019QZKK0702), the National Natural Science Foundation of China (41930215, 42272053), and the MOST Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (MSFGPMR2022-6).

Funding

The Second Tibetan Plateau Scientific Expedition and Research Program (STEP), 2019QZKK0702, Jianping Zheng, the National Natural Science Foundation of China, 41930215, Jian-Ping Zheng, 42272053, Hong-Kun Dai, the MOST Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, MSFGPMR2022-6, Qing Xiong

Author information

Authors and Affiliations

Authors

Corresponding authors

Correspondence to Jian-Ping Zheng or Hong-Kun Dai.

Ethics declarations

Conflict of interest

The authors declare no competing interests.

Additional information

Communicated by Dante Canil.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (XLSX 59 KB)

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wang, M., Zheng, JP., Dai, HK. et al. Formation and prolonged preservation of dense arc root cumulates: insights from retrograded eclogite xenoliths in the western Yangtze craton. Contrib Mineral Petrol 179, 24 (2024). https://doi.org/10.1007/s00410-024-02099-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s00410-024-02099-z

Keywords

Navigation