Skip to main content
Log in

Origin of the Low δ18O Signals in Zircons from the Early Cretaceous A-Type Granites in Eastern China: Evidence from the Kulongshan Pluton

  • Published:
Journal of Earth Science Aims and scope Submit manuscript

Abstract

The origin of low δ18O signals in zircons from the Early Cretaceous A-type granites in eastern China has long been disputed. It is uncertain whether the 18O-depleted features were inherited from high-temperature hydrothermal altered source rock or resulted from water-rock interaction after emplacement. In this paper, zircon oxygen isotopes in the ∼130 Ma Kulongshan A-type granites in the northern North China Craton are analyzed. The zircons could be subdivided into 5 types based on their luminescent intensity and internal structures in CL images. Their δ18O values also vary in different types and show negative correlation with U and Th contents and accompanying cumulative α-decay doses, implying that their δ18O values may have been modified to various degrees by meteoric water-rock interaction after the accumulation of radiation damage. The idea is further confirmed by oxygen isotopic equilibrium calculation between co-existing mineral pairs. It is inferred that only the least-influenced zircons, with slightly elevated δ18O values than normal mantle, have preserved the magmatic oxygen isotopes. In combination with other evidences, it is proposed that the A-type granites are lower-crustal-derived, unnecessarily invoking a high-temperature hydrothermal altered source. The proposition is applicable to many other Cretaceous A-type granites that have similar zircon behaviors.

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.

Institutional subscriptions

Similar content being viewed by others

References Cited

Download references

Acknowledgments

We would like to thank Xianhua Li, Qiuli Li, Hongxia Ma, Jiao Li and Guoqiang Tang for their assistance with zircon U-Pb and O isotopes, Xin Yan and Saihong Yang for zircon SEM, Yueheng Yang and Liewen Xie for LA-MC-ICPMS zircon Hf isotopes, Qian Mao and Di Zhang for EPMA, Jianqi Wang, Yongsheng Liu and Keqing Zong for whole rock geochemistry, Chaofeng Li, Youlian Li and Weiyi Li for Nd isotopes and for Hanbin Liu, Jun Yan and Mingyan Zhu for oxygen isotopes analysis. The anonymous reviewers are also thanked for their constructive comments. This study was supported by the National Natural Science Foundation of China (No. 41973034) and the Postdoctoral Initiation Fund of Northwestern University (No. 208521). The final publication is available at Springer via https://doi.org/10.1007/s12583-021-1515-y.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Wenbo Fan.

Electronic Supplementary Materials

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Fan, W., Jiang, N., Zhai, M. et al. Origin of the Low δ18O Signals in Zircons from the Early Cretaceous A-Type Granites in Eastern China: Evidence from the Kulongshan Pluton. J. Earth Sci. 32, 1415–1427 (2021). https://doi.org/10.1007/s12583-021-1515-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12583-021-1515-y

Key words

Navigation