Abstract
The metamorphosed Early Paleoproterozoic granitoids in the Quanji massif, Northwestern China provide constraints for relationship between the Tarim Craton and North China Craton. Among granitoids batholiths, rocks of the Mohe quartz-diorite show typically adakitic geochemical characteristics, with medium K2O/Na2O ratios (0.56-1.17) and high Sr (519-619 ppm) low Y (9.37-20.40 ppm) and Yb (0.97-1.77 ppm) concentrations. The rocks have e{open} Nd(t) values between +2.4 and +4.4 and depleted mantle Nd model ages of 2.43-2.59 Ga. The magmatic zircons have positive e{open} Hf(t) values ranging from +0.40 to +7.60 and depleted mantle Hf model ages of 2.43-2.70 Ga, with major peaks at ∼2.54 and ∼2.65 Ga. The geochemical and Nd-Hf isotopic characteristics indicate that the Mohe quartz-dioritic rocks might be formed by partial melting of high-pressure metamorphosed juvenile crustal rocks in post-orogenic extensional regime in the Early Paleoproterozoic. It suggests that important crustal growth occurred in the Quanji massif and the Tarim Craton at ∼2.4 and 2.5-2.7 Ga. The Quanji massif and Tarim Craton might share a similar crustal evolution history with the North China Craton in the Neoarchean.
Original language | English |
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Pages (from-to) | 74-86 |
Number of pages | 13 |
Journal | Journal of Earth Science |
Volume | 25 |
Issue number | 1 |
Early online date | 24 Jan 2014 |
DOIs | |
Publication status | Published - Feb 2014 |
Externally published | Yes |
Bibliographical note
We appreciated Prof. Timothy M Kusky for his carefully polishing work and valuable comments to the revised manuscript. Two anonymous reviewers were thanked for their critical and constructive suggestions.Funding
This study was supported by the National Natural Science Foundation of China (Nos. 40972042 and 41172069), Hong Kong RGC (No. HKU704312P) and the Fundamental Research Funds for the Central Universities of of Ministry of Education, China.
Keywords
- crustal growth
- high-Sr and low-Y granitoid
- North China Craton
- Quanji massif
- Tarim Craton
- zircon Hf isotope